| Diagnosis and Testing Refer to Wiring Diagrams Section 417-01, for schematic and connector information. Special Tool(s) | | Terminal Probe Kit 29-011A | Inspection and Checking NOTE:The generic electronic module (GEM) forms part of the central junction box (CJB). NOTE:If the generic electronic module (GEM) 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: Kommunikations-Netzwerk (418-00, Diagnosis and Testing), Zentralelektrikmodul (GEM) (419-10, Diagnosis and Testing). 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 damage.
Visual Inspection | Electrical | - Fuse(s)
- Bulb(s)
- Fog lamps
- Connectors
- Switches
- Wiring harness
| - 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 | | Fog lamps are inoperative | * Fuse(s) * Circuit(s) * Headlight switch * Rear fog lamp cut-off relay | * | | One fog lamp is inoperative | * Circuit(s) * Fog lamps * Rear fog lamp | * | | Rear fog lamps or front fog lamps illuminate continuously | * Circuit(s) * Headlight switch * Rear fog lamp cut-off relay | * | System Checks NOTE:Use a digital multimeter for all electrical measurements. | PINPOINT TEST A : FOG LAMPS ARE INOPERATIVE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: DETERMINE THE FAULT CONDITION | NOTE:Vehicles with trailer socket: Ensure that no adapters are connected to the trailer socket. | | | 1 Ignition switch in position II. | | | 2 SWITCH ON the front and rear fog lamps. | | | 3 Check the fog lamps. | | | Are all fog lamps inoperative? Yes No - Front fog lamps inoperative: GO to A5. | | A2: CHECK FUSE F62 (15 A) (CJB). | | | 1 Ignition switch in position 0. | | | 2 Disconnect fuse F62 (15 A) (CJB). | | | 3 CHECK Fuse F62 (15 A) (CJB). | | | Is the fuse OK.? Yes No RENEW fuse F62 (15 A) (CJB). CHECK the operation of the system. If the fuse blows again, LOCATE and RECTIFY the short to ground using the Wiring Diagrams. CHECK the operation of the system. | | A3: CHECK THE VOLTAGE SUPPLY TO FUSE F62 (15 A) (CJB) FOR OPEN CIRCUIT | | | 1 Connect fuse F62 (15 A) (CJB). | | | 2 Ignition switch in position II. | | | 3 Measure the voltage between fuse F62 (15 A) (CJB) and ground. | | | Is battery voltage measured? Yes No RENEW the CJB. CHECK the operation of the system. | | A4: CHECK FOR OPEN CIRCUIT BETWEEN FUSE F62 (15 A) (CJB) AND THE HEADLIGHT SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect Headlight switch from connector C478. | | | 3 Measure the resistance between the headlight switch, connector C478, pin 7, circuit 15-LD10 (GN/OG), wiring harness side and fuse F62 (CJB). | | | Is a resistance of less than 2 Ohms registered? Yes RENEW the headlight switch. CHECK the operation of the system. No LOCATE and RECTIFY the break in the circuit between fuse F62 (CJB) and the headlight switch using the Wiring Diagrams. CHECK the operation of the system. | | A5: CHECK THE HEADLIGHT SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect Headlight switch from connector C478. | | | 3 Using a fused bridging cable (15 A) at the headlight switch, connect between connector C478, pin 7, circuit 15-LD10 (GN/OG) and pin 3, circuit 15S-LD10 (GN/OG), wiring harness side. | | | 4 Ignition switch in position II. | | | 5 Check the front fog lamps. | | | Do the front fog lamps illuminate? Yes RENEW the headlight switch. CHECK the operation of the system. No | | A6: CHECK CIRCUITS 15S-LD10 (GN/OG) AND 15S-LD9 (GN/BK) BETWEEN THE HEADLIGHT SWITCH AND SOLDERED CONNECTION S733 FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Connect Headlight switch to connector C478. | | | 3 Disconnect left-hand front fog lamp from connector C208. | | | 4 Ignition switch in position II. | | | 5 Switch on the front fog lamps. | | | 6 Vehicles built up to 04/2005 | | | 7 Measure the voltage between the left-hand front fog lamp, connector C208, pin 2, circuit 15S-LD17 (GN/WH), wiring harness side and ground. | | | 8 Vehicles built from 04/2005 | | | 9 Measure the voltage between the left-hand front fog lamp, connector C208, pin 1, circuit 15S-LD17 (GN/WH), wiring harness side and ground. | | | Is battery voltage measured? Yes LOCATE and RECTIFY the break in the circuit between soldered connection S734 and ground connection G104 using the Wiring Diagrams. CHECK the operation of the system. No LOCATE and RECTIFY the break in circuit 15S-LD10 (GN/OG) or 15S-LD9 (GN/BK), between the headlight switch and soldered connection S733 using the Wiring Diagrams. CHECK the operation of the system. | | A7: CHECK THE HEADLIGHT SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect Headlight switch from connector C478. | | | 3 Using a fused bridging cable (15 A) at the headlight switch, connect between connector C478, pin 7, circuit 15-LD10 (GN/OG) and pin 2, circuit 15S-LD16 (GN/RD), wiring harness side. | | | 4 Ignition switch in position II. | | | 5 If the rear fog lamps are still inoperative, remove the bridging wire (estate versions without trailer socket only). | | | 6 Check the rear fog lamps. | | | Do the rear fog lamps illuminate? Yes RENEW the headlight switch. CHECK the operation of the system. No -4/5 door without trailer socket: GO to A8. - Estate version, without trailer socket: LOCATE and REPAIR the break in circuit 15S-LD16 (GN/RD) or 15S-LD6 (GN/YE) between the headlight switch and intermediate connector C540a, pin 7 using the Wiring Diagrams. CHECK the operation of the system. - Vehicles with trailer socket: GO to A9. | | A8: CHECK CIRCUITS 15S-LD16 (GN/RD) AND 15S-LD6 (GN/YE) FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Left-hand rear lamp assembly. - 4/5-door version, without trailer socket and without parking aid: from connector C540
- 4/5-door version, without trailer socket and with parking aid: from connector C1038
| | | 3 Ignition switch in position II. | | | 4 Measure the voltage between left-hand rear lamp assembly: - 4/5-door version, without trailer socket and without parking aid: connector C540, pin 7, circuit 15S-LD6 (GN/YE), wiring harness side and ground.
- 4/5-door version, without trailer socket and with parking aid: connector C1038, pin 7, circuit 15S-LD12 (GN/YE), wiring harness side and ground.
| | | Is battery voltage measured? Yes LOCATE and RECTIFY the break in circuit 31-DA7 (BK), between soldered connection S211 and ground G300 using the Wiring Diagrams. CHECK the operation of the system. No -4/5-door version, without trailer socket and without parking aid: LOCATE and RECTIFY the break in the circuit between the headlight switch and the left-hand rear lamp assembly using the Wiring Diagrams. CHECK the operation of the system. -4/5-door version, without trailer socket and with parking aid: LOCATE and RECTIFY the break in the circuit between headlight switch and intermediate connector C540, pin 7 using the Wiring Diagrams. CHECK the operation of the system. | | A9: CHECK CIRCUITS 15S-LD16 (GN/RD) AND 15S-LD6 (GN/YE) BETWEEN THE HEADLIGHT SWITCH AND THE REAR FOG LAMP CUT-OFF RELAY FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Rear fog lamp cut-off relay from socket C2008. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the rear fog lamp cut-off relay, socket C2008, circuit (RD/WH), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and RECTIFY the break in circuit 15S-LD16 (GN/RD), 15S-LD6 (GN/YE), 15S-LD12 (GN/YE) or (RD/WH) between the headlight switch and the rear fog lamp cut-off relay using the Wiring Diagrams. CHECK the operation of the system. | | A10: CHECK THE GROUND CONNECTION OF THE REAR FOG LAMP CUT-OFF RELAY FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the rear fog lamp cut-off relay, socket C2008, circuit (BN), wiring harness side and ground. | | | Is a resistance of less than 2 Ohms registered? Yes No LOCATE and RECTIFY the break in the circuit between the rear fog lamp cut-off relay and soldered connection S811 using the Wiring Diagrams. CHECK the operation of the system. | | A11: CHECK CIRCUIT (RD/YE) BETWEEN THE REAR FOG LAMP CUT-OFF RELAY AND THE TRAILER SOCKET FOR SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the rear fog lamp cut-off relay, socket C2008, circuit (RD/YE), wiring harness side and ground. | | | Is a resistance of more than 10,000 ohms measured? Yes RENEW the rear fog lamp cut-off relay CHECK the operation of the system. No LOCATE and RECTIFY the short to ground in the circuit between the rear fog lamp cut-off relay and the trailer socket using the Wiring Diagrams. CHECK the operation of the system. | | PINPOINT TEST B : ONE FOG LAMP IS INOPERATIVE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: DETERMINE INOPERATIVE LAMP(S) | | | 1 Ignition switch in position II. | | | 2 SWITCH ON the front and rear fog lamps. | | | 3 Check the fog lamps. | | | Is a single fog lamp inoperative? Yes No - Left-hand rear fog lamp, estate and 4/5-door with parking aid: GO to B8. - Left-hand rear fog lamp, 4/5-door without trailer socket and without parking aid: GO to B9. | | B2: CHECK THE VOLTAGE SUPPLY OF THE LEFT-HAND FRONT FOG LAMP FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect left-hand front fog lamp from connector C208. | | | 3 Ignition switch in position II. | | | 4 Switch on the front fog lamps. | | | 5 Vehicles built up to 04/2005 | | | 6 Measure the voltage between the left-hand front fog lamp, connector C208, pin 2, circuit 15S-LD17 (GN/WH), wiring harness side and ground. | | | 7 Vehicles built from 04/2005 | | | 8 Measure the voltage between the left-hand front fog lamp, connector C208, pin 1, circuit 15S-LD17 (GN/WH), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and RECTIFY the break in the circuit between soldered connection S733 and the left-hand front fog lamp using the Wiring Diagrams. CHECK the operation of the system. | | B3: CHECK THE GROUND CONNECTION OF THE LEFT-HAND FRONT FOG LAMP FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Vehicles built up to 04/2005 | | | 3 Measure the resistance between the left-hand front fog lamp, connector C208, pin 1, circuit 31-LD17 (BK), wiring harness side and ground. | | | 4 Vehicles built from 04/2005 | | | 5 Measure the resistance between the left-hand front fog lamp, connector C208, pin 2, circuit 31-LD17 (BK), wiring harness side and ground. | | | Is a resistance of less than 2 Ohms registered? Yes CHECK and if necessary RENEW the left-hand front fog lamp. CHECK the operation of the system. No LOCATE and RECTIFY the break in the circuit between the left-hand front fog lamp and soldered connection S734 using the Wiring Diagrams. CHECK the operation of the system. | | B4: CHECK THE VOLTAGE SUPPLY OF THE RIGHT-HAND FRONT FOG LAMP FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect right-hand front fog lamp from connector C207. | | | 3 Ignition switch in position II. | | | 4 Switch on the front fog lamps. | | | 5 Vehicles built up to 04/2005 | | | 6 Measure the voltage between the right-hand front fog lamp, connector C207, pin 2, circuit 15S-LD11 (GN/WH), wiring harness side and ground. | | | 7 Vehicles built from 04/2005 | | | 8 Measure the voltage between the right-hand front fog lamp, connector C207, pin 1, circuit 15S-LD11 (GN/WH), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and RECTIFY the break in the circuit between soldered connection S733 and the right-hand front fog lamp using the Wiring Diagrams. CHECK the operation of the system. | | B5: CHECK THE GROUND CONNECTION OF THE RIGHT-HAND FRONT FOG LAMP FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Vehicles built up to 04/2005 | | | 3 Measure the resistance between the right-hand front fog lamp, connector C207, pin 1, circuit 31-LD11 (BK), wiring harness side and ground. | | | 4 Vehicles built from 04/2005 | | | 5 Measure the resistance between the right-hand front fog lamp, connector C207, pin 2, circuit 31-LD11 (BK), wiring harness side and ground. | | | Is a resistance of less than 2 Ohms registered? Yes CHECK and if necessary RENEW the right-hand front fog lamp. CHECK the operation of the system. No LOCATE and RECTIFY the break in the circuit between the right-hand front fog lamp and soldered connection S734 using the Wiring Diagrams. CHECK the operation of the system. | | B6: CHECK THE VOLTAGE SUPPLY TO THE RIGHT-HAND REAR LAMP ASSEMBLY FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Right-hand rear lamp assembly. - 4/5-door version, without trailer socket: from connector C541
- 4/5-door version, with trailer socket: from connector C2007
- Estate version: from connector C1553
| | | 3 Ignition switch in position II. | | | 4 SWITCH ON the rear fog lamp. | | | 5 Measure the voltage between the right-hand rear lamp assembly: - 4/5-door version, without trailer socket: connector C541, pin 7, circuit 15S-LD12 (GN/YE), wiring harness side and ground.
- 4/5-door version, with trailer socket: Connector C2007, pin 7, circuit (VT/YE), wiring harness side and ground.
- Estate version: connector C1553, pin 3, circuit 15S-LD6 (GN/YE), wiring harness side and ground.
| | | Is battery voltage measured? Yes No -4/5-door without trailer socket and without parking aid: LOCATE and RECTIFY the break in circuit 15S-LG12 (GN/YE) between the left-hand rear lamp assembly and the right-hand rear lamp assembly using the Wiring Diagrams. CHECK the operation of the system. -4/5-door version, without trailer socket and with parking aid: LOCATE and RECTIFY the break in circuit 15S-LD12 (GN/YE) between the right-hand rear lamp assembly and intermediate connector C540, pin 7 using the Wiring Diagrams. CHECK the operation of the system. - Estate version, without trailer socket: LOCATE and RECTIFY the break in circuit 15S-LD6 (GN/YE) or 15S-LD12 (GN/YE) between the right-hand rear lamp assembly and intermediate connector C540a, pin 7 using the Wiring Diagrams. CHECK the operation of the system. - Vehicles with trailer socket: LOCATE and RECTIFY the break in the circuit between the rear fog lamp cut-off relay, connector C2008 and the right-hand rear lamp assembly using the Wiring Diagrams. CHECK the operation of the system. | | B7: CHECK THE GROUND CONNECTION TO THE RIGHT-HAND REAR LAMP ASSEMBLY FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the right-hand rear lamp assembly: - 4/5-door version, without trailer socket: connector C541, pin 6, circuit 31-LF20 (BK), wiring harness side and ground.
- 4/5-door version, with trailer socket: connector C2007, pin 6, circuit (GN), wiring harness side and ground.
- Estate version: connector C1553, pin 1, circuit 31-LF11 (BK), wiring harness side and ground.
| | | Is a resistance of less than 2 Ohms registered? Yes CHECK and if necessary RENEW the right-hand rear lamp assembly. CHECK the operation of the system. No LOCATE and RECTIFY the break in the circuit between the right-hand rear lamp assembly and soldered connection S211 (4/5 door) or S713 (estate) using the Wiring Diagrams. CHECK the operation of the system. | | B8: CHECK THE VOLTAGE SUPPLY TO THE LEFT-HAND REAR LAMP ASSEMBLY FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Left-hand rear lamp assembly. - 4/5-door version, without trailer socket and with parking aid: from connector C1038
- 4/5-door version with trailer socket: from connector C2005
- Estate version: from connector C1543
| | | 3 Ignition switch in position II. | | | 4 SWITCH ON the rear fog lamp. | | | 5 Measure the voltage between left-hand rear lamp assembly: - 4/5-door version, without trailer socket and with parking aid: connector C1038, pin 7, circuit 15S-LD12 (GN/YE), wiring harness side and ground.
- 4/5-door version with trailer socket: connector C2005, pin 7, circuit (VT/YE), wiring harness side and ground.
- Estate version: connector C1543, pin 3, circuit 15S-LD6 (GN/YE), wiring harness side and ground.
| | | Is battery voltage measured? Yes No -4/5-door version, without trailer socket and with parking aid: LOCATE and RECTIFY the break in the circuit between the left-hand rear lamp assembly and intermediate connector C1037, pin 7 using the Wiring Diagrams. CHECK the operation of the system. -4/5-door version with trailer socket: LOCATE and RECTIFY the break in the circuit between the left-hand rear lamp assembly and the rear fog lamp cut-off relay using the Wiring Diagrams. CHECK the operation of the system. - Estate version, without trailer socket: LOCATE and RECTIFY the break in the circuit between the left-hand rear lamp assembly and intermediate connector C540a, pin 7 using the Wiring Diagrams. CHECK the operation of the system. - Estate with trailer socket: LOCATE and RECTIFY the break in circuit (VT/YE) between the left-hand rear lamp assembly and the rear fog lamp cut-off relay using the Wiring Diagrams. CHECK the operation of the system. | | B9: CHECK THE GROUND CONNECTION TO THE LEFT-HAND REAR LAMP ASSEMBLY FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Left-hand rear lamp assembly. - 4/5-door version, without trailer socket and without parking aid: from connector C540
| | | 3 Measure the resistance between the left-hand rear lamp assembly: - 4/5-door version, without trailer socket and without parking aid: connector C540, pin 6, circuit 31-LF11 (BK), wiring harness side and ground.
- 4/5-door version, without trailer socket and with parking aid: connector C1038, pin 6, circuit 31-LF20 (BK), wiring harness side and ground.
- 4/5-door version, with trailer socket: connector C2005, pin 6, circuit (BN), wiring harness side and ground.
- Estate version: connector C1543, pin 1, circuit 31-LF11 (BK), wiring harness side and ground.
| | | Is a resistance of less than 2 Ohms registered? Yes CHECK and if necessary RENEW the left-hand rear lamp assembly. CHECK the operation of the system. No LOCATE and RECTIFY the break in the circuit between the left-hand rear lamp assembly and soldered connection S211 (4/5 door) or S712 (estate) using the Wiring Diagrams. CHECK the operation of the system. | | PINPOINT TEST C : REAR FOG LAMPS OR FRONT FOG LAMPS ILLUMINATE CONTINUOUSLY | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | C1: CHECK THE HEADLIGHT SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect Headlight switch from connector C478. | | | 3 Ignition switch in position II. | | | 4 Check the fog lamps. | | | Do the fog lamps illuminate? Yes - Rear fog lamps permanently lit, vehicles without trailer socket: LOCATE and RECTIFY the short to battery voltage in circuit 15S-LD16 (GN/RD), 15S-LD6 (GN/YE) or 15S-LD12 (GN/YE) between the headlight switch and the rear fog lamps using the Wiring Diagrams. CHECK the operation of the system. - Rear fog lamps illuminate continuously, vehicles with trailer socket: GO to C2. - Front fog lamps permanently lit: LOCATE and REPAIR the short to battery voltage in circuit 15S-LD9 (GN/BK), 15S-LD10 (GN/OG), 15S-LD11 (GN/WH) or 15S-LD17 (GN/WH) between the headlight switch and the front fog lamps using the Wiring Diagrams. CHECK the operation of the system. No RENEW the headlight switch. CHECK the operation of the system. | | C2: NARROW DOWN THE FAULT CONDITION | | | 1 Ignition switch in position 0. | | | 2 Disconnect rear fog lamp cut-off relay from socket 2008. | | | 3 Ignition switch in position II. | | | 4 Check the fog lamps. | | | Do the rear fog lamps illuminate? Yes LOCATE and RECTIFY the short to battery voltage in circuit (VT/YE) or 15S-LD6 (GN/YE) (estate) between the rear fog lamp cut-off relay and the rear fog lamp using the Wiring Diagrams. CHECK the operation of the system. No | | C3: CHECK THE REAR FOG LAMP CUT-OFF RELAY | | | 1 Measure the voltage between the rear fog lamp cut-off relay, socket C2008, circuit (RD/WH), wiring harness side and ground. | | | Is battery voltage measured? Yes LOCATE and RECTIFY the short to battery voltage in the circuits connected to the headlamp switch, connector C478, pin 2 using the Wiring Diagrams. CHECK the operation of the system. No RENEW the rear fog lamp cut-off relay CHECK the operation of the system. | |
