| Diagnosis and Testing Refer to Wiring Diagrams Section 417-01, for schematic and connector information. Special Tool(s) | | Terminal Probe Kit 29-011A | Diagnosis and Testing NOTE:The generic electronic module (GEM) forms part of the central junction box (CJB). NOTE:If the generic electronic module (GEM) or the gas discharge headlamp control module is changed, the new one must be reinitialised. For this purpose, the vehicle-specific data is read out of the module to be replaced using WDS and is transferred to the new module. REFER to: Module Configuration (418-01 Module Configuration, General Procedures), Generic Electronic Module (GEM) (419-10 Multifunction Electronic Modules, Removal and Installation). NOTE:Before reading out the vehicle-specific data, remake all the electrical connections to the module to be removed, so that communication between the module and WDS is ensured. - Verify the customer concern.
- Visually inspect for obvious signs of electrical (or mechanical) damage.
Visual Inspection | Mechanical | Electrical | - Headlamp
- Headlamp adjuster unit
| - Fuse(s)
- Connector(s)
- Switches
- Wiring harness
- Headlamp levelling sensors
- Gas discharge headlamp control module
| - Resolve any obvious causes or concerns found during the visual inspection before carrying out any further tests.
- If the concern is not visually evident, refer to the Symptom Chart.
Symptom Chart Symptom Chart | Symptom | Possible Sources | Action | | Headlamp levelling system is inoperative, vehicles with conventional headlamps. | * Fuse * Circuit(s) * Headlamp adjust variable resistor * Adaptive front lighting module * Left/right-hand headlamp * Central Junction Box (CJB) | * | | Headlamp levelling system is inoperative, vehicles with gas discharge headlamps. | * Fuse * Circuit(s) * Gas discharge headlamp control module * Front/rear headlamp levelling sensor * Gas discharge headlamp left-/right-hand side | * | Pinpoint Tests NOTE:Use a digital multimeter for all electrical measurements. | PINPOINT TEST A : HEADLAMP LEVELLING SYSTEM IS INOPERATIVE, VEHICLES WITH CONVENTIONAL HEADLAMPS. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: DETERMINE THE FAULT CONDITION | | | 1 Determine the fault condition. | | | Does the headlamp range control of both headlamps function incorrectly? Yes INSTALL A NEW headlight switch. CHECK the operation of the system. No - Left or right-hand side malfunctioning: CHECK the headlamp levelling unit in the relevant headlamp and if necessary RENEW. CHECK the operation of the system. | | A2: DETERMINE THE EQUIPMENT LEVEL OF THE CENTRAL JUNCTION BOX (CJB). | | | 1 Unfasten the CJB and fold it down. | | | Is the location for connector C100 on the top of the CJB? Yes No | | A3: CHECK FUSE F115 (CJB) | | | 1 Ignition switch in position 0. | | | 2 Disconnect Fuse F115 (7.5 A) (CJB). | | | 3 CHECK Fuse F115 (7.5 A) (CJB). | | | Is the fuse OK.? Yes No RENEW fuse F115 (7.5 A) and CHECK the operation of the system. If fuse blows again, LOCATE and REMEDY the short to ground with the aid of the wiring diagrams. CHECK the operation of the system. | | A4: CHECK VOLTAGE AT FUSE F115 (CJB) | | | 1 Connect Fuse F115 (7.5 A) (CJB). | | | 2 Ignition switch in position II. | | | 3 Measure the voltage between fuse F115 (7.5 A) (CJB) and ground. | | | Does the meter display battery voltage? Yes No RECTIFY the break in the voltage supply to fuse F115 (CJB) with the aid of the wiring diagrams. CHECK the operation of the system. CHECK and RENEW the CJB if necessary. CHECK the operation of the system. | | A5: CHECK FUSE F66 (CJB) | | | 1 Ignition switch in position 0. | | | 2 Disconnect fuse F66 (7.5 A) (CJB). | | | 3 CHECK fuse F66 (7.5 A) (CJB). | | | Is the fuse OK.? Yes No RENEW fuse F66 (7.5 A) and CHECK the operation of the system. If fuse blows again, LOCATE and REMEDY the short to ground with the aid of the wiring diagrams. CHECK the operation of the system. | | A6: CHECK THE VOLTAGE AT FUSE F66 (CJB) | | | 1 Connect fuse F66 (7.5 A) (CJB). | | | 2 Ignition switch in position II. | | | 3 Measure the voltage between fuse F66 (7.5 A) (CJB) and ground. | | | Does the meter display battery voltage? Yes No RECTIFY the break in the voltage supply of fuse F66 (CJB) with the aid of the wiring diagrams. CHECK the operation of the system. CHECK and RENEW the CJB if necessary. CHECK the operation of the system. | | A7: CHECK THE VOLTAGE SUPPLY OF THE HEADLIGHT SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect Headlight switch from connector C320. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the headlight switch, connector C320, pin 8, circuit 15-LE29 (GN/BK), wiring harness side and ground. | | | Does the meter display battery voltage? Yes No LOCATE and RECTIFY the break in the circuit between fuse F66 (CJB) and the headlight switch using the wiring diagrams. CHECK the operation of the system. | | A8: CHECK THE GROUND CONNECTION OF THE HEADLAMP ADJUSTMENT VARIABLE RESISTOR IN THE HEADLAMP SWITCH | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the headlamp switch, connector C320, pin 10, circuit 31-LE29 (BK), wiring harness side and ground. | | | Is the resistance less than 2 Ohm? Yes No LOCATE and RECTIFY the break in the circuit between the headlight switch and soldered connection S7 using the wiring diagrams. CHECK the operation of the system. | | A9: CHECK THE HEADLIGHT SWITCH | | | 1 CHECK the headlamp switch according to the component check at the end of this section. | | | Is the headlight switch OK? Yes - vehicles without adaptive front lighting: GO to A14. - vehicles with adaptive front lighting: GO to A10. No INSTALL A NEW headlight switch. CHECK the operation of the system. | | A10: CHECK CONTROL CIRCUIT OF HEADLAMP RANGE CONTROL FOR OPEN CIRCUIT | | | 1 Connect Headlight switch with connector C320. | | | 2 Disconnect Adaptive front lighting module from connector C838. | | | 3 Ignition switch in position II. | | | 4 SWITCH ON dipped beam. | | | 5 CHANGE the SETTING of the headlamp leveling system during the measurement (UP/DOWN). | | | 6 Measure the voltage between adaptive front lighting module, connector C838, pin 14, circuit 8-LE46B (WH/RD), wiring harness side and ground. | | | Does the voltage measured vary proportionally with the setting of the variable resistor? Yes No - Constant battery voltage is measured: LOCATE and RECTIFY the short to battery voltage in the circuits connected to the headlamp switch, C320, pin 1 using the Wiring Diagrams. CHECK the operation of the system. | | A11: CHECK VOLTAGE SUPPLY TO ADAPTIVE FRONT LIGHTING MODULE FOR OPEN CIRCUIT | | | 1 Measure the voltage between adaptive front lighting module, connector C838, pin 23, circuit 15-LE58 (GN/OG), wiring harness side and ground. | | | Does the meter display battery voltage? Yes No LOCATE and RECTIFY the break in the circuit between fuse F66 (CJB) and the adaptive front lighting module using the Wiring Diagrams. CHECK the operation of the system. | | A12: CHECK GROUND CONNECTION TO ADAPTIVE FRONT LIGHTING MODULE FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between adaptive front lighting module, connector C838, pin 24, circuit 91-LE58 (BK/RD), wiring harness side and ground. | | | Is less than 2 Ohm measured? Yes CHECK the adaptive front lighting module using WDS, RENEW if necessary. CHECK the operation of the system. No LOCATE and RECTIFY break in circuit between adaptive front lighting module and soldered connection S12 with the aid of the wiring diagrams. CHECK the operation of the system. | | A13: CHECK CONTROL CIRCUIT OF HEADLAMP LEVELLING SYSTEM FOR SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Disconnect Headlight switch from connector C320. | | | 3 Measure the resistance between adaptive front lighting module, connector C838, pin 14, circuit 8-LE46B (WH/RD), wiring harness side and ground. | | | Is the resistance more than 10,000 Ohm? Yes LOCATE and RECTIFY the break in the circuit between the headlight switch and adaptive front lighting module using the wiring diagrams. CHECK the operation of the system. No LOCATE and RECTIFY the short to ground in the circuit connected to the light switch, connector C320, pin 1 using the Wiring Diagrams. CHECK the operation of the system. | | A14: CHECK CONTROL CIRCUIT OF HEADLAMP RANGE CONTROL FOR OPEN CIRCUIT | | | 1 Connect Headlight switch with connector C320. | | | 2 Disconnect left-hand headlamp from connector C836. | | | 3 Disconnect right-hand headlamp from connector C837. | | | 4 Ignition switch in position II. | | | 5 SWITCH ON dipped beam. | | | 6 CHANGE the SETTING of the headlamp leveling system during the measurement (UP/DOWN). | | | 7 Measure the voltage between left-hand headlamp, connector C836, pin 9, circuit 8-LE56 (WH/BU), wiring harness side and ground. | | | Does the voltage measured vary proportionally with the setting of the variable resistor? Yes No - Constant battery voltage is measured: LOCATE and RECTIFY the short to battery voltage in the circuits connected to the headlamp switch, C320, pin 1 using the Wiring Diagrams. CHECK the operation of the system. | | A15: CHECK THE COMMON GROUND OF THE HEADLAMP ADJUSTMENT UNITS FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between left-hand headlamp, connector C836, pin 7, circuit 9-LE45 (BN), wiring harness side and ground. | | | Is the resistance less than 2 Ohm? Yes No LOCATE and RECTIFY the break in the circuit between soldered connection S7 and ground connection G20 using the Wiring Diagrams. CHECK the operation of the system. | | A16: CHECK RIGHT-HAND HEADLAMP FOR SHORT TO BATTERY VOLTAGE | | | 1 Connect right-hand headlamp to connector C837. | | | 2 Ignition switch in position II. | | | 3 SWITCH ON dipped beam. | | | 4 CHANGE the SETTING of the headlamp range control (UP/DOWN). | | | 5 Check the right-hand headlamp position. | | | Can the headlamp range be adjusted correctly? Yes CHECK and if necessary INSTALL A NEW left-hand headlamp. CHECK the operation of the system. No CHECK and if necessary INSTALL A NEW right-hand headlamp. CHECK the operation of the system. | | A17: CHECK CONTROL CIRCUIT OF HEADLAMP LEVELLING SYSTEM FOR SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between left-hand headlamp, connector C836, pin 9, circuit 8-LE56 (WH/BU), wiring harness side and ground. | | | Is the resistance more than 10,000 Ohm? Yes No | | A18: CHECK HEADLAMP SWITCH FOR SHORT TO GROUND | | | 1 Disconnect Headlight switch from connector C320. | | | 2 Measure the resistance between left-hand headlamp, connector C836, pin 9, circuit 8-LE56 (WH/BU), wiring harness side and ground. | | | Is the resistance more than 10,000 Ohm? Yes INSTALL A NEW headlight switch. CHECK the operation of the system. No LOCATE and RECTIFY the short to ground in the circuits connected to the headlight switch, connector C320, pin 1 using the Wiring Diagrams. CHECK the operation of the system. | | A19: CHECK CONTROL CIRCUIT OF HEADLAMP RANGE CONTROL FOR OPEN CIRCUIT | | | 1 Disconnect Headlight switch from connector C320. | | | 2 Measure resistance between headlamp switch, connector C320, pin 1, circuit 8-LE46A (WH/RD), wiring harness side and headlamp, left, connector C836, pin 9, circuit 8-LE56 (WH/BU), wiring harness side. | | | Is the resistance less than 2 Ohm? Yes No LOCATE and RECTIFY break in circuit between headlamp switch and intermediate connection C111 with the aid of the wiring diagrams. CHECK the operation of the system. | | A20: CHECK RIGHT-HAND HEADLAMP FOR SHORT TO GROUND | | | 1 Connect right-hand headlamp to connector C837. | | | 2 Connect Headlamp switch with C320. | | | 3 Ignition switch in position II. | | | 4 SWITCH ON dipped beam. | | | 5 CHANGE the SETTING of the headlamp range control (UP/DOWN). | | | 6 Check the right-hand headlamp position. | | | Can the headlamp range be adjusted correctly? Yes CHECK and if necessary INSTALL A NEW left-hand headlamp. CHECK the operation of the system. No CHECK and if necessary INSTALL A NEW right-hand headlamp. CHECK the operation of the system. | | A21: CHECK CONTROL VOLTAGE AT LEFT-HAND HEADLAMP | | | 1 Ignition switch in position 0. | | | 2 Disconnect Left-hand headlamp from connector. - Vehicles without adaptive front lighting: C836
- Vehicles with adaptive front lighting: C842
| | | 3 Ignition switch in position II. | | | 4 SWITCH ON dipped beam. | | | 5 CHANGE the SETTING of the headlamp leveling system during the measurement (UP/DOWN). | | | 6 Measure voltage between the left-hand headlamps: - Vehicles without adaptive front lighting: Connector C836, pin 9, circuit 8-LE56 (WH/BU), wiring harness side and ground.
- Vehicles with adaptive front lighting: Connector C842, pin 2, circuit 7-LE56 (YE/BU), wiring harness side and ground.
| | | Does the voltage measured vary proportionally with the setting of the variable resistor? Yes No Vehicles without adaptive front lighting: LOCATE and RECTIFY break in circuit(s) between headlamp and intermediate connection C111 with the aid of the wiring diagrams. CHECK the operation of the system. Vehicles with adaptive front lighting: GO to A22. | | A22: CHECK CONTROL CIRCUIT OF LEFT HEADLAMP LEVELING FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Adaptive front lighting module from connector C838. | | | 3 Measure resistance between adaptive front lighting module, connector C838, pin 9, circuit 7-LE56 (YE/BU), wiring harness side and headlamp, left, connector C842, pin 2, circuit 7-LE56 (YE/BU), wiring harness side. | | | Is the resistance less than 2 Ohm? Yes CHECK the adaptive front lighting module using WDS, RENEW if necessary. CHECK the operation of the system. No LOCATE and RECTIFY break in circuit(s) between adaptive front lighting module and headlamp with the aid of the wiring diagrams. CHECK the operation of the system. | | A23: CHECK GROUND CONNECTION TO LEFT-HAND HEADLAMP | | | 1 Ignition switch in position 0. | | | 2 Measure resistance between the left-hand headlamp: - Vehicles without adaptive front lighting: Connector C836, pin 7, circuit 9-LE45 (BN), wiring harness side and ground.
- Vehicles with adaptive front lighting: Connector C842, pin 1, circuit 31-LE56 (BK), wiring harness side and ground.
| | | Is the resistance less than 2 Ohm? Yes Visually inspect and if necessary RENEW the headlamp and headlamp adjuster unit. CHECK the operation of the system. No - vehicles without adaptive front lighting: LOCATE and REPAIR the break in the circuit(s) between headlamp and soldered connection S7 using the Wiring Diagrams. CHECK the operation of the system. - vehicles with adaptive front lighting: LOCATE and REPAIR the break in the circuit(s) between headlamp and soldered connection S121 using the Wiring Diagrams. CHECK the operation of the system. | | A24: CHECK CONTROL VOLTAGE AT RIGHT-HAND HEADLAMP | | | 1 Ignition switch in position 0. | | | 2 Disconnect Right-hand headlamp from connector. - Vehicles without adaptive front lighting: C837
- Vehicles with adaptive front lighting: C843
| | | 3 Ignition switch in position II. | | | 4 SWITCH ON dipped beam. | | | 5 CHANGE the SETTING of the headlamp leveling system during the measurement (UP/DOWN). | | | 6 Measure voltage between the right-hand headlamps: - Vehicles without adaptive front lighting: Connector C837, pin 9, circuit 8-LE57 (WH/GN), wiring harness side and ground.
- Vehicles with adaptive front lighting: Connector C843, pin 2, circuit 7-LE57 (YE/GN), wiring harness side and ground.
| | | Does the voltage measured vary proportionally with the setting of the variable resistor? Yes No - vehicles without adaptive front lighting: LOCATE and RECTIFY break in circuit(s) between headlamp and intermediate connection C111 with the aid of the wiring diagrams. CHECK the operation of the system. - vehicles with adaptive front lighting: GO to A25. | | A25: CHECK CONTROL CIRCUIT OF RIGHT-HAND HEADLAMP LEVELING FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Adaptive front lighting module from connector C838. | | | 3 Measure resistance between adaptive front lighting module, connector C838, Pin 5, circuit 7-LE57 (YE/GN), wiring harness side and headlamp, right, connector C843, pin 2, circuit 7-LE57 (YE/GN), wiring harness side. | | | Is the resistance less than 2 Ohm? Yes CHECK the adaptive front lighting module using WDS, RENEW if necessary. CHECK the operation of the system. No LOCATE and RECTIFY break in circuit(s) between adaptive front lighting module and headlamp with the aid of the wiring diagrams. CHECK the operation of the system. | | A26: CHECK GROUND CONNECTION AT THE RIGHT-HAND HEADLAMP | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the right-hand headlamp: - Vehicles without adaptive front lighting: Connector C837, pin 7, circuit 9-LE46 (BN/RD), wiring harness side and ground.
- Vehicles with adaptive front lighting: Connector C843, pin 1, circuit 31-LE57 (BK), wiring harness side and ground.
| | | Is the resistance less than 2 Ohm? Yes Visually inspect and if necessary RENEW the headlamp and headlamp adjuster unit. CHECK the operation of the system. No - vehicles without adaptive front lighting: LOCATE and REPAIR the break in the circuit(s) between headlamp and soldered connection S7 using the Wiring Diagrams. CHECK the operation of the system. - vehicles with adaptive front lighting: LOCATE and REPAIR the break in the circuit(s) between headlamp and soldered connection S109 using the Wiring Diagrams. CHECK the operation of the system. | | PINPOINT TEST B : HEADLAMP LEVELLING SYSTEM IS INOPERATIVE, VEHICLES WITH GAS DISCHARGE HEADLAMPS. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: DETERMINE THE FAULT CONDITION | | | 1 Determine the fault condition. | | | Is the headlamp leveling system inoperative for both headlamps? Yes No | | B2: DETERMINE THE EQUIPMENT LEVEL OF THE CENTRAL JUNCTION BOX (CJB). | | | 1 Unfasten the CJB and fold it down. | | | Is the location for connector C100 on the top of the CJB? Yes No | | B3: CHECK FUSE F115 (CJB) | | | 1 Ignition switch in position 0. | | | 2 Disconnect Fuse F115 (7.5 A) (CJB). | | | 3 CHECK Fuse F115 (7.5 A) (CJB). | | | Is the fuse OK.? Yes No RENEW fuse F115 (7.5 A) and CHECK the operation of the system. If fuse blows again, LOCATE and REMEDY the short to ground with the aid of the wiring diagrams. CHECK the operation of the system. | | B4: CHECK VOLTAGE AT FUSE F115 (CJB) | | | 1 Connect Fuse F115 (CJB). | | | 2 Ignition switch in position II. | | | 3 Measure the voltage between fuse F115 (7.5 A) (CJB) and ground. | | | Does the meter display battery voltage? Yes No RECTIFY the break in the voltage supply to fuse F115 (CJB) with the aid of the wiring diagrams. CHECK the operation of the system. CHECK and RENEW the CJB if necessary. CHECK the operation of the system. | | B5: CHECK FUSE F66 (CJB) | | | 1 Ignition switch in position 0. | | | 2 Disconnect fuse F66 (7.5 A) (CJB). | | | 3 CHECK fuse F66 (7.5 A) (CJB). | | | Is the fuse OK.? Yes No RENEW fuse F66 (7.5 A) and CHECK the operation of the system. If fuse blows again, LOCATE and REMEDY the short to ground with the aid of the wiring diagrams. CHECK the operation of the system. | | B6: CHECK THE VOLTAGE AT FUSE F66 (CJB) | | | 1 Connect Fuse F66 (CJB). | | | 2 Ignition switch in position II. | | | 3 Measure the voltage between fuse F66 (7.5 A) (CJB) and ground. | | | Does the meter display battery voltage? Yes No RECTIFY the break in the voltage supply of fuse F66 (CJB) with the aid of the wiring diagrams. CHECK the operation of the system. CHECK and RENEW the CJB if necessary. CHECK the operation of the system. | | B7: CHECK THE VOLTAGE SUPPLY TO THE GAS DISCHARGE HEADLAMP CONTROL MODULE | | | 1 Ignition switch in position 0. | | | 2 Disconnect Gas discharge headlamp control module from connector C838. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between gas discharge headlamp control module, connector C838, pin 23, circuit 15-LE58 (GN/OG), wiring harness side and ground. | | | Does the meter display battery voltage? Yes No LOCATE and RECTIFY the break in the circuit between fuse F66 (CJB) and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. | | B8: CHECK THE GROUND SUPPLY TO THE GAS DISCHARGE HEADLAMP CONTROL MODULE | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between gas discharge headlamp control module, connector C838, pin 24, circuit 91-LE58 (BK/RD), wiring harness side and ground. | | | Is the resistance less than 2 Ohm? Yes No LOCATE and RECTIFY the break in the circuit between the gas discharge headlamp control module and soldered connection S12 using the wiring diagrams. CHECK the operation of the system. | | B9: CHECK FOR BREAK IN CIRCUITS TO FRONT HEADLAMP LEVELLING SENSOR | | | 1 Ignition switch in position 0. | | | 2 Disconnect front headlamp levelling sensor from connector C323. | | | 3 Measure the resistance between the headlamp levelling sensor, front, connector C323, pin 1, circuit 9-LE53 (BN/BU), wiring harness side and gas discharge headlamp control module, connector C838, pin 11, circuit 9-LE53 (BN/BU), wiring harness side. | | | 4 Measure the resistance between the headlamp levelling sensor, front, connector C323, pin 4, circuit 8-LE53 (WH/BU), wiring harness side and gas discharge headlamp control module, connector C838, pin 6, circuit 8-LE53 (WH/BU), wiring harness side. | | | 5 Measure the resistance between the headlamp levelling sensor, front, connector C323, pin 5, circuit 7-LE53 (YE/BU), wiring harness side and gas discharge headlamp control module, connector C838, pin 25, circuit 7-LE53 (YE/BU), wiring harness side. | | | Is the resistance in all the measurements less than 2 Ohms? Yes No LOCATE and RECTIFY the break in the relevant circuit between the headlamp levelling sensor and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. | | B10: CHECK FOR BREAK IN CIRCUITS TO REAR HEADLAMP LEVELLING SENSOR | | | 1 Disconnect rear headlamp levelling sensor from connector C839. | | | 2 Measure the resistance between the headlamp levelling sensor, rear, connector C839, pin 1, circuit 9-LE54 (BN/YE), wiring harness side and gas discharge headlamp control module, connector C838, pin 12, circuit 9-LE54 (BN/YE), wiring harness side. | | | 3 Measure the resistance between the headlamp levelling sensor, rear, connector C839, pin 4, circuit 8-LE54 (WH/BK), wiring harness side and gas discharge headlamp control module, connector C838, pin 7, circuit 8-LE54 (WH/BK), wiring harness side. | | | 4 Measure the resistance between the headlamp levelling sensor, rear, connector C839, pin 5, circuit 7-LE54 (YE/BK), wiring harness side and gas discharge headlamp control module, connector C838, pin 10, circuit 7-LE54 (YE/BK), wiring harness side. | | | Is the resistance in all the measurements less than 2 Ohms? Yes No LOCATE and RECTIFY the break in the relevant circuit between the headlamp levelling sensor and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. | | B11: CHECK VOLTAGE SUPPLY TO FRONT HEADLAMP LEVELLING SENSOR | | | 1 Connect Gas discharge headlamp control module with connector C838. | | | 2 Ignition switch in position II. | | | 3 SWITCH ON dipped beam. | | | 4 Measure the voltage between the headlamp levelling sensor, front, connector C323, pin 5, circuit 7-LE53 (YE/BU), wiring harness side and pin 1, circuit 9-LE53 (BN/BU), wiring harness side. | | | Is a voltage of 5 Volts measured? Yes No CHECK the gas discharge headlamp control module using WDS, RENEW if necessary. CHECK the operation of the system. | | B12: CHECK VOLTAGE SUPPLY TO REAR HEADLAMP LEVELLING SENSOR. | | | 1 Measure the voltage between the headlamp levelling sensor, rear, connector C839, pin 5, circuit 7-LE54 (YE/BK), wiring harness side and pin 1, circuit 9-LE54 (BN/YE), wiring harness side. | | | Is a voltage of 5 Volts measured? Yes No CHECK the gas discharge headlamp control module using WDS, RENEW if necessary. CHECK the operation of the system. | | B13: CHECK THE SIGNAL CABLE OF THE HEADLAMP LEVELLING SENSOR (FRONT) FOR A SHORT TO BATTERY VOLTAGE | | | 1 Measure the voltage between the headlamp levelling sensor, front, connector C323, pin 4, circuit 8-LE53 (WH/BU), wiring harness side and ground. | | | Does the meter display battery voltage? Yes LOCATE and RECTIFY the short to battery voltage in the circuits connected to the headlamp levelling sensor, front, connector C323, pin 4 with the aid of the Wiring Diagrams. CHECK the operation of the system. No | | B14: CHECK THE SIGNAL CABLE OF THE HEADLAMP LEVELLING SENSOR (FRONT) FOR A SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the headlamp levelling sensor, front, connector C323, pin 4, circuit 8-LE53 (WH/BU), wiring harness side and ground. | | | Is the resistance more than 10,000 Ohm? Yes No LOCATE and RECTIFY the short to ground in the circuits connected to the headlamp levelling sensor, front, connector C323, pin 4 with the aid of the Wiring Diagrams. CHECK the operation of the system. | | B15: CHECK THE SIGNAL CABLE OF THE HEADLAMP LEVELLING SENSOR (REAR) FOR A SHORT TO BATTERY VOLTAGE | | | 1 Ignition switch in position II. | | | 2 SWITCH ON dipped beam. | | | 3 Measure the voltage between the headlamp levelling sensor, rear, connector C839, pin 4, circuit 8-LE54 (WH/BK), wiring harness side and ground. | | | Does the meter display battery voltage? Yes LOCATE and RECTIFY the short to battery voltage in the circuits connected to the headlamp levelling sensor, rear, connector C839, pin 4 with the aid of the Wiring Diagrams. CHECK the operation of the system. No | | B16: CHECK THE SIGNAL CABLE OF THE HEADLAMP LEVELLING SENSOR (REAR) FOR A SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the headlamp levelling sensor, rear, connector C839, pin 4, circuit 8-LE54 (WH/BK), wiring harness side and ground. | | | Is the resistance more than 10,000 Ohm? Yes CHECK the front and rear headlamp levelling sensors and RENEW if necessary. CHECK the operation of the system. If the concern persists, CHECK the gas discharge headlamp control module using WDS and RENEW if necessary. CHECK the operation of the system. No LOCATE and RECTIFY the short to ground in the circuits connected to the headlamp levelling sensor, rear, connector C839, pin 4 with the aid of the Wiring Diagrams. CHECK the operation of the system. | | B17: CHECK FOR BREAK IN CIRCUITS TO LEFT-HAND ADJUSTER UNIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Gas discharge headlamp control module from connector C838. | | | 3 Disconnect Left-hand gas discharge headlamp from connector C836. | | | 4 Measure the resistance between the gas discharge headlamp, left, connector C836, pin 5, circuit 8-LE45 (WH), wiring harness side and gas discharge headlamp control module, connector C838, pin 17, circuit 8-LE45 (WH), wiring harness side. | | | 5 Measure the resistance between the gas discharge headlamp, left, connector C836, pin 7, circuit 9-LE45 (BN), wiring harness side and gas discharge headlamp control module, connector C838, pin 19, circuit 9-LE45 (BN), wiring harness side. | | | 6 Measure the resistance between the gas discharge headlamp, left, connector C836, pin 9, circuit 8-LE56 (WH/BU), wiring harness side and gas discharge headlamp control module, connector C838, pin 16, circuit 8-LE56 (WH/BU), wiring harness side. | | | 7 Measure the resistance between the gas discharge headlamp, left, connector C836, pin 10, circuit 9-LE56 (BN/BU), wiring harness side and gas discharge headlamp control module, connector C838, pin 18, circuit 9-LE56 (BN/BU), wiring harness side. | | | Is the resistance in all the measurements less than 2 Ohms? Yes No LOCATE and RECTIFY the break in the relevant circuit between the gas discharge headlamp, left, and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. | | B18: CHECK CIRCUITS FOR SHORT TO BATTERY VOLTAGE | | | 1 Ignition switch in position II. | | | 2 Measure the voltage between the gas discharge headlamp, left, connector C836: - pin 5, circuit 8-LE45 (WH), wiring harness side and ground.
- pin 7, circuit 9-LE45 (BN), wiring harness side and ground.
- pin 9, circuit 8-LE56 (WH/BU), wiring harness side and ground.
- pin 10, circuit 9-LE56 (BN/BU), wiring harness side and ground.
| | | Does the meter display battery voltage? Yes LOCATE and RECTIFY the short to battery voltage in the relevant circuit between the gas discharge headlamp, left, and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. No | | B19: CHECK CIRCUITS FOR SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the gas discharge headlamp, left, connector C836: - pin 5, circuit 8-LE45 (WH), wiring harness side and ground.
- pin 7, circuit 9-LE45 (BN), wiring harness side and ground.
- pin 9, circuit 8-LE56 (WH/BU), wiring harness side and ground.
- pin 10, circuit 9-LE56 (BN/BU), wiring harness side and ground.
| | | Is the resistance more than 10,000 Ohm? Yes Continue fault finding using WDS and if necessary CHECK and RENEW the headlamp and gas discharge headlamp control module. CHECK the operation of the system. No LOCATE and RECTIFY the short to ground in the relevant circuit between the gas discharge headlamp, left, and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. | | B20: CHECK FOR BREAK IN CIRCUITS TO RIGHT-HAND ADJUSTER UNIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Gas discharge headlamp control module from connector C838. | | | 3 Disconnect Gas discharge headlamp, right from connector C837. | | | 4 Measure the resistance between the gas discharge headlamp, right, connector C837, pin 5, circuit 8-LE46 (WH/RD), wiring harness side and gas discharge headlamp control module, connector C838, pin 15, circuit 8-LE46 (WH/RD), wiring harness side. | | | 5 Measure the resistance between the gas discharge headlamp, right, connector C837, pin 7, circuit 9-LE46 (BN/RD), wiring harness side and gas discharge headlamp control module, connector C838, pin 21, circuit 9-LE46 (BN/RD), wiring harness side. | | | 6 Measure the resistance between the gas discharge headlamp, right, connector C837, pin 9, circuit 8-LE57 (WH/GN), wiring harness side and gas discharge headlamp control module, connector C838, pin 22, circuit 8-LE57 (WH/GN), wiring harness side. | | | 7 Measure the resistance between the gas discharge headlamp, right, connector C837, pin 10, circuit 9-LE57 (BN/GN), wiring harness side and gas discharge headlamp control module, connector C838, pin 20, circuit 9-LE57 (BN/GN), wiring harness side. | | | Is the resistance in all the measurements less than 2 Ohms? Yes No LOCATE and RECTIFY the break in the relevant circuit between the gas discharge headlamp, right, and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. | | B21: CHECK CIRCUITS FOR SHORT TO BATTERY VOLTAGE | | | 1 Ignition switch in position II. | | | 2 Measure the voltage between the gas discharge headlamp, right, connector C837: - pin 5, circuit 8-LE46 (WH/RD), wiring harness side and ground.
- pin 7, circuit 9-LE46 (BN/RD), wiring harness side and ground.
- pin 9, circuit 8-LE57 (WH/GN), wiring harness side and ground.
- pin 10, circuit 9-LE57 (BN/GN), wiring harness side and ground.
| | | Does the meter display battery voltage? Yes LOCATE and RECTIFY the short to battery voltage in the relevant circuit between the gas discharge headlamp, right, and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. No | | B22: CHECK CIRCUITS FOR SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the gas discharge headlamp, right, connector C837: - pin 5, circuit 8-LE46 (WH/RD), wiring harness side and ground.
- pin 7, circuit 9-LE46 (BN/RD), wiring harness side and ground.
- pin 9, circuit 8-LE57 (WH/GN), wiring harness side and ground.
- pin 10, circuit 9-LE57 (BN/GN), wiring harness side and ground.
| | | Is the resistance more than 10,000 Ohm? Yes Continue fault finding using WDS and if necessary CHECK and RENEW the headlamp and gas discharge headlamp control module. CHECK the operation of the system. No LOCATE and RECTIFY the short to ground in the relevant circuit between the gas discharge headlamp, right, and the gas discharge headlamp control module using the Wiring Diagrams. CHECK the operation of the system. | Component Tests Headlight switch - Test the resistance of the headlamp levelling control switch:
- Measure the resistance at the headlamp switch between pin 8, component side, and pin 10, component side.
- Test the resistance of the headlamp levelling control switch during adjustment:
- Measure the resistance at the headlamp switch between pin 8, component side, and pin 1, component side.
- Adjust the headlamp levelling control switch from min. to max.
- Does the resistance measured change smoothly from 0 to 4.7 kOhm?
1. If yes, the headlamp levelling control switch is OK. 2. If no, RENEW the headlamp switch. |
