| Diagnosis and Testing Special Tool(s) | | 73III Automotive Meter 105-R0057 or equivalent | | | SABRE Premium Battery and Electrical System Tester 010-00736 or equivalent | | | Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool | | | Flex Probe Kit 105-R025B | Principles of Operation This vehicle is equipped with a powertrain control module (PCM)-controlled charging system which determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator. This system is unique in that it has 2 unidirectional communication lines between the PCM and the generator/regulator. Both of these communication lines are pulse-width modulated (PWM). The generator communication (GEN COM) line communicates the desired setpoint from the PCM to the voltage regulator. The generator monitor (GEN MON) line communicates the generator load and error conditions to the PCM. The third pin on the voltage regulator, the A circuit pin, is a dedicated battery voltage sense line. The PCM uses a calibratable algorithm to estimate battery temperature and to reduce battery damage caused by over and under charging. Using this algorithm, the PCM determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator on the GEN COM circuit. While this is occurring, the PCM is also monitoring the GEN MON circuit for charging system information, such as transient electrical loads or errors. If the PCM senses when the charging system receives a transient electrical load (which may cause poor idle quality, such as an idle roll) the PCM can then adjust the injectors opening time to account for the transient electrical load. In this manner, the PCM can maintain a consistent idle speed. If the PCM detects a charging system error, it broadcasts a CHARGING SYSTEM STATE STATUS message through the controller area network (CAN) communication link, causing the instrument cluster to illuminate the charging system warning indicator. The charging system warning indicator is illuminated if the PCM fails to see a signal on the GEN MON circuit for a time period greater than 500 ms. This telltale is used to indicate over-voltage conditions detected by the PCM. The PCM also reduces the mechanical load on the starter by initially commanding a low voltage setpoint (using the GEN COM circuit) in order to improve start times and reduce load on the starter and its related system. Each time the key is cycled to the ON position, the instrument cluster initiates a bulb check by illuminating the charging system warning indicator. This operation is called prove-out. The PCM then issues a CHARGING SYSTEM STATE STATUS - OK message if the charging system is functioning properly. This message is sent once the engine is running and the charging system is determined to be operating correctly. If the cluster does not receive an OK message, the cluster lights the charging system warning indicator indefinitely. Vehicles equipped with a message center display CHECK CHARGING SYSTEM any time a charging system error is present. This is a System 4 charging system, which uses the GEN MON and GEN COM lines to control and monitor the charging system through the PCM. System 4 charging systems are virtually identical in design and therefore, share the same diagnostics. The circuit numbers and colors may be different, but the functions are the same. System 4 charging systems may use any type of generator, as the generator type usually depends on the engine packaging and/or output requirements versus cost. Circuit Description Positive Battery Output (B+) Terminal Circuit 38 (BK/OG) (2.3L) The generator output voltage is supplied through the positive battery output (B+) terminal circuit 38 (BK/OG) on the rear of the generator to the battery and electrical system. Positive Battery Output (B+) Terminal Circuit 36 (YE/WH) (3.0L) The generator output voltage is supplied through the positive battery output (B+) terminal circuit 36 (YE/WH) on the rear of the generator to the battery and electrical system. A Circuit 112 (BK/YE) This is the A terminal battery voltage sense circuit and it is used to sense battery voltage. Circuit 921 (GY/OG) The generator monitor (GEN MON) circuit communicates the generator load and error conditions to the powertrain control module (PCM). Circuit 920 (BN/WH) This is the generator communication (GEN COM) circuit. The PCM determines the optimal voltage setpoint for the charging system and communicates this information to the voltage regulator through the GEN COM circuit. Inspection and Verification WARNING:Batteries contain sulfuric acid. Avoid contact with skin, eyes, or clothing. Also, shield your eyes when working near batteries to protect against possible splashing of the acid solution. In case of acid contact with skin or eyes, flush immediately with water for a minimum of 15 minutes and get prompt medical attention. If acid is swallowed, call a physician immediately. Failure to follow these instructions may result in personal injury. WARNING:Batteries normally produce explosive gases. Therefore, do not allow flames, sparks or lighted substances to come near the battery. When charging or working near a battery, always shield your face and protect your eyes. Always provide ventilation. Failure to follow these instructions may result in personal injury. WARNING:When lifting a battery, excessive pressure on the end walls could cause acid to spew through the vent caps, resulting in personal injury, damage to the vehicle or battery. Lift with a battery carrier or with your hands on opposite corners. Failure to follow these instructions may result in personal injury. CAUTION:Do not make jumper connections except as directed. Incorrect connections may damage the voltage regulator test terminals, fuses, or fusible links. CAUTION:Do not allow any metal object to come in contact with the generator housing and internal diode cooling fins. A short circuit may result and burn out the diodes. NOTE:While carrying out any pinpoint test, disregard any diagnostic trouble codes (DTCs) set while following a specific pinpoint test. After the completion of a test, be sure to clear all DTCs in the PCM. NOTE: All voltage measurements are referenced to the negative (-) battery post unless otherwise specified. - Verify the customer concern.
- Visually inspect for obvious signs of mechanical or electrical damage.
Visual Inspection Chart | Mechanical | Electrical | - Battery
- Generator drive belt
- Generator pulley
| - Battery junction box (BJB) fuse 9 (15A)
- Circuitry
- Fusible links
- Cables
- Generator
- Powertrain control module (PCM)
- Charging system warning indicator
| - If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- Check the operation of the charging system warning indicator (instrument cluster). Normal operation is as follows:
- With the key OFF, the charging system warning indicator should be off.
- With the key ON and the engine OFF, the charging system warning indicator should be on.
- With the engine running, the charging system warning indicator should be off.
- Turn off the headlamps and the A/C system (if equipped). Turn the climate control blower to low/off. Check the battery voltage before and after starting the engine to determine if the battery voltage increases.
-
NOTE:Make sure to use the latest scan tool software release. If the cause is not visually evident, connect the scan tool to the data link connector (DLC). -
NOTE:The vehicle communication module (VCM) LED prove out confirms power and ground from the DLC are provided to the VCM. If the scan tool does not communicate with the VCM: - check the VCM connection to the vehicle.
- check the scan tool connection to the VCM.
- If the scan tool does not communicate with the vehicle:
- verify the ignition key is in the ON position.
- verify the scan tool operation with a known good vehicle.
- Carry out the network test.
- If the network test passes, retrieve and record continuous memory diagnostic trouble codes (DTCs).
- Clear the continuous DTCs and carry out the self-test diagnostics for the powertrain control module (PCM) and the instrument cluster.
- If the DTCs retrieved are related to the concern, go to Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index. For all other DTCs, refer to Section 419-10 Multifunction Electronic Modules.
- If no DTCs related to the concern are retrieved, GO to Symptom Chart.
NOTE:DTC P0622 can be set by the loss of the communication lines between the generator and the PCM. The charging system warning indicator then illuminates until the engine is operated at greater than 4,500 rpm (approximately wide open throttle [WOT]) for a minimum of 3 seconds. At this time, the generator self-excites. The charging system warning indicator remains illuminated, and the generator operates in a default mode (approximately 13.5 volts) until the engine is turned off. Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index | DTC | Description | Source | Action | | P0622 | Generator Field Term Cir | PCM | GO to Symptom Chart. | | All Other DTCs | — | PCM | REFER to the REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual.. | Instrument Cluster Diagnostic Trouble Code (DTC) Index Symptom Chart Symptom Chart | Symptom | Possible Sources | Action | | The battery is discharged or battery voltage is low | * Battery * Generator * High key-off current drain(s) * Engine, generator and battery grounds * Positive battery cable | * | | The charging system warning indicator is on with the engine running (the charging system voltage does not increase) | * Circuitry * Generator * Powertrain control module (PCM) | * | | The charging system overcharges (battery voltage is greater than 15.5 volts) | * Circuitry * Generator * Powertrain control module (PCM) | * | | The charging system warning indicator is on with the engine running and the battery increases voltage | * Generator * Instrument cluster * Powertrain control module (PCM) | * | | The charging system warning indicator is off with the ignition switch in the RUN position and the engine off | * Instrument cluster * Powertrain control module (PCM) | * | | The charging system warning indicator flickers or is intermittent | * Instrument cluster | * | | The generator is noisy | * Loose bolts/brackets * Accessory drive belt * Generator/pulley | * | | Radio interference | * Generator * In-vehicle entertainment system | * | Pinpoint Tests Pinpoint Test A: The Battery Is Discharged or Battery Voltage Is Low Refer to Wiring Diagrams Cell 12, for schematic and connector information. Normal Operation The generator output is supplied through the battery positive output (B+) circuit 38 (BK/OG) (2.3L), 36 (YE/WH) (3.0L), terminal on the rear of the generator to the battery and electrical system. During normal operation the charging system warning indicator is off with the key in the ON position and the engine running. The charging system warning indicator is on with the key in the ON position and the engine off. Possible Causes - Battery
- Generator
- Generator B+ circuit 38 (BK/OG) (2.3L) high resistance
- Generator B+ circuit 36 (YE/WH) (3.0L) high resistance
- High key-off current drain(s)
- Engine, generator and battery grounds
- Positive battery cable
| PINPOINT TEST A : THE BATTERY IS DISCHARGED OR BATTERY VOLTAGE IS LOW | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: CHECK THE BATTERY CONDITION | | | 1 | | | Does the battery pass the condition test? Yes No | | A2: CHECK THE GENERATOR OUTPUT | | | 1 Carry out the Generator On-Vehicle Load Test and No Load Test. Refer to Component Tests in this section. | | | Does the generator pass the component tests? Yes No | | A3: CHECK FOR CURRENT DRAINS | | | 1 Carry out the Battery — Drain Testing. Refer to Component Tests in this section. | | | Are any circuits causing excessive current drains? Yes REPAIR as necessary. TEST the system for normal operation. No | | A4: CHECK THE VEHICLE GROUNDS | | | 1 Ignition switch in position III. | | | 2 With the engine running, measure the voltage drop between the generator housing and the negative battery terminal. | | | Is the voltage drop less than 0.1 volt? Yes No CHECK the engine ground, generator ground and the battery ground for corrosion. TEST the system for normal operation. | | A5: CHECK THE VOLTAGE DROP IN THE B+ CIRCUIT | | | 1 With the engine running, measure the voltage drop between generator B+ C102c-, circuit 38 (BK/OG) (2.3L), or C102b-, circuit 36 (YE/WH) (3.0L), and the positive battery terminal. | | | Is the voltage drop less than 0.1 volt? Yes VERIFY if the customer left any component(s) on or if there is an intermittent excessive battery draw. TEST the system for normal operation. No CHECK for any corrosion in the positive battery cable and/or connections. REPAIR as necessary. TEST the system for normal operation. | Pinpoint Test B: The Charging System Warning Indicator Is On With The Engine Running (The Charging System Voltage Does Not Increase) Refer to Wiring Diagrams Cell 12, for schematic and connector information. Normal Operation With the engine running, the charging system warning indicator is off. The sense A circuit 112 (BK/YE) to the generator field coil is 13-15 volts. The S (stator) circuit (internal to the generator) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage is used by the powertrain control module (PCM) to turn off the charging system warning indicator. The battery positive output (B+) circuit 38 (BK/OG) (2.3L), circuit 36 (YE/WH) (3.0L), is the generator output supplied to the battery and electrical system. Possible Causes - Generator B+ circuit 38 (BK/OG) (2.3L) open or high resistance
- Generator B+ circuit 36 (YE/WH) (3.0L) open or high resistance
- GEN MON circuit 921 (GY/OG) open or shorted to ground
- GEN COM circuit 920 (BN/WH) open or shorted to ground
- Generator
- PCM
| PINPOINT TEST B : THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING (THE CHARGING SYSTEM VOLTAGE DOES NOT INCREASE) | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: CHECK THE FAULT CODES IN THE PCM | | | 1 Connect the diagnostic tool. | | | 2 Ignition switch in position II. | | | 3 Enter the following diagnostic mode: Retrieve PCM DTCs. | | | 4 Check the recorded PCM DTCs from the continuous and on-demand self tests. | | | Are any PCM DTCs recorded? Yes REFER to the REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual.. If referred here by the REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual., GO to B2. . No | | B2: CHECK THE GENERATOR B+ CIRCUIT FOR VOLTAGE | | | 1 Ignition switch in position 0. | | | 2 Measure the voltage between generator C102c-, circuit 38 (BK/OG) (2.3L), C102b-, circuit 36 (YE/WH) (3.0L), and ground. | | | Is the voltage approximately equal to battery positive voltage? Yes No REPAIR the circuit. TEST the system for normal operation. | | B3: CHECK THE GENERATOR INTEGRITY | | | 1 Disconnect Generator C102a. | | | 2 Key in the ON position, engine OFF. | | | 3 Measure and record the battery voltage. | | | 4 Ignition switch in position III. | | | NOTE:If the generator communication lines are disconnected (DTC P0622 may set), the generator self-excites if it is operated at greater than 4,500 rpm (approximately wide open throttle [WOT]) for a minimum of 3 seconds. It then operates in a default mode at 13.5 volts until the engine is turned off. 5 With the engine running (after the brief WOT is carried out), measure the battery voltage. | | | Does the battery voltage increase a minimum of 0.5 volt from the key ON, engine OFF measurement to the key ON, engine running measurement (after the brief WOT or snap acceleration is carried out)? Yes No | | B4: CHECK CIRCUIT 920 (BN/WH) FOR AN OPEN OR SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Disconnect PCM C175e. | | | 3 Measure the resistance between generator C102a-2, circuit 920 (BN/WH), harness side and PCM C175e-7, circuit 920 (BN/WH), harness side and between generator C102a-2, circuit 920 (BN/WH), harness side and ground | | | Is the resistance less than 5 ohms between the generator and the PCM, and greater than 10,000 ohms between the generator and ground? Yes No REPAIR the circuit. TEST the system for normal operation. | | B5: CHECK CIRCUIT 921 (GY/OG) FOR AN OPEN OR SHORT TO GROUND | | | 1 Measure the resistance between generator C102a-1, circuit 921 (GY/OG), harness side and PCM C175e-16, circuit 921 (GY/OG), harness side and between generator C102a-1, circuit 921 (GY/OG), harness side and ground | | | Is the resistance less than 5 ohms between the generator and the PCM, and greater than 10,000 ohms between the generator and ground? Yes No REPAIR the circuit. TEST the system for normal operation. | | B6: CHECK FOR CORRECT PCM OPERATION | | | 1 Disconnect all PCM connectors. | | | 2 Check for: | | | 3 Connect all PCM connectors and make sure they seat correctly. | | | 4 Operate the system and verify the concern is still present. | | | Is the concern still present? Yes No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. | Pinpoint Test C: The Charging System Overcharges (Battery Voltage Is Greater Than 15.5 Volts) Refer to Wiring Diagrams Cell 12, for schematic and connector information. Normal Operation The generator output is determined by the voltage of the A circuit 112 (BK/YE). The A circuit voltage is compared to a set voltage internal to the regulator and the regulator controls the generator field current to maintain the correct generator output. The set voltage varies with temperature and is typically higher in cold temperatures and lower in warm temperatures. Possible Causes - A circuit 112 (BK/YE) high resistance
- Generator
- Powertrain control module (PCM)
| PINPOINT TEST C : THE CHARGING SYSTEM OVERCHARGES (BATTERY VOLTAGE IS GREATER THAN 15.5 VOLTS) | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | C1: CHECK THE FAULT CODES IN THE PCM | | | 1 Connect the diagnostic tool. | | | 2 Ignition switch in position II. | | | 3 Enter the following diagnostic mode: Retrieve PCM DTCs. | | | 4 Check the recorded PCM DTCs from the continuous and on-demand self tests. | | | Are any PCM DTCs recorded? Yes REFER to the REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual.. If referred here by the REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual., GO to C2. . No | | C2: CHECK THE BATTERY VOLTAGE | | | 1 Ignition switch in position 0. | | | 2 Disconnect the diagnostic tool. | | | 3 Ignition switch in position III. | | | 4 With the engine running and all the accessories turned off, measure the voltage at the battery while varying the engine rpm. | | | Is the voltage greater than 15.5 volts? Yes No | | C3: CHECK FOR A VOLTAGE DROP IN CIRCUIT 112 (BK/YE) | | | 1 Ignition switch in position 0. | | | 2 Disconnect Generator C102a. | | | 3 Measure the voltage between generator C102a-3, circuit 112 (BK/YE), harness side and ground. | | | Is the voltage within 0.5 volt from battery voltage? Yes No REPAIR the circuit for high resistance. TEST the system for normal operation. | | C4: CHECK THE GENERATOR PIDS | | | 1 Connect the diagnostic tool. | | | 2 Ignition switch in position III. | | | 3 Enter the following diagnostic mode: Monitor PCM PIDs. | | | 4 With the engine running, monitor the generator output fault PID in the PCM. | | | Does the PID read YES? Yes No | | C5: CHECK THE GENERATOR INTEGRITY | | | 1 Ignition switch in position 0. | | | 2 Disconnect Generator C102a. | | | 3 Key in the ON position, engine OFF. | | | 4 Measure and record the battery voltage. | | | 5 Ignition switch in position III. | | | NOTE:If the generator communication lines are disconnected (DTC P0622 may set), the generator self-excites if it is operated at greater than 4,500 rpm (approximately wide open throttle [WOT]) for a minimum of 3 seconds. It then operates in a default mode at 13.5 volts until the engine is turned off. 6 With the engine running (after the brief WOT is carried out), measure the battery voltage. | | | Does the battery voltage increase a minimum of 0.5 volt from the key ON, engine OFF measurement to the key ON, engine running measurement (after the brief WOT or snap acceleration is carried out)? Yes No | | C6: CHECK FOR CORRECT PCM OPERATION | | | 1 Disconnect all the PCM connectors. | | | 2 Check for: | | | 3 Connect all the PCM connectors and make sure they seat correctly. | | | 4 Operate the system and verify the concern is still present. | | | Is the concern still present? Yes No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. | Pinpoint Test D: The Charging System Warning Indicator Is On With The Engine Running And The Battery Increases Voltage Refer to Wiring Diagrams Cell 12, for schematic and connector information. Normal Operation With the engine running, the charging system warning indicator is off. The sense A circuit 112 (BK/YE) to the generator field coil is 13-15 volts. The S (stator) circuit (internal to the generator) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage is monitored by the powertrain control module (PCM) to turn off the charging system warning indicator. The battery positive output (B+) circuit 38 (BK/OG) (2.3L), or circuit 36 (YE/WH) (3.0L), is the generator output supplied to the battery and electrical system. Possible Causes - Generator
- Instrument cluster
- PCM
| PINPOINT TEST D : THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING AND THE BATTERY INCREASES VOLTAGE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | D1: CHECK THE FAULT CODES IN THE PCM | | | 1 Connect the diagnostic tool. | | | 2 Ignition switch in position II. | | | 3 Enter the following diagnostic mode: Retrieve PCM DTCs. | | | 4 Check the recorded PCM DTCs from the continuous and on-demand self tests. | | | Are any PCM DTCs recorded? Yes REFER to the REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual.. If referred here by the REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual., GO to D2. . No | | D2: CHECK THE SYSTEM FOR OVERCHARGING | | | 1 Ignition switch in position III. | | | 2 With the engine running and all accessories off, measure the voltage at the battery terminals while varying the engine rpm. | | | Is the voltage greater than 15.5 volts? Yes No | | D3: CHECK THE CHARGING SYSTEM WARNING INDICATOR OPERATION | | | 1 Enter the following diagnostic mode: Monitor PCM PIDs. | | | 2 With the engine running, monitor the generator output fault PID in the PCM. | | | Does the PID read YES? Yes No REFER to Section 413-01 Instrument Cluster to diagnose the charging system warning indicator. TEST the system for normal operation. | | D4: CHECK THE GENERATOR OUTPUT | | | 1 Verify the generator output. Refer to Component Tests, Generator On-Vehicle Tests in this section. | | | Does the generator pass the component tests? Yes No | | D5: CHECK FOR CORRECT PCM OPERATION | | | 1 Ignition switch in position 0. | | | 2 Disconnect all the PCM connectors. | | | 3 Check for | | | 4 Connect all the PCM connectors and make sure they seat correctly. | | | 5 Operate the system and verify the concern is still present. | | | Is the concern still present? Yes No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. | Pinpoint Test E: The Charging System Warning Indicator Is Off With The Ignition Switch In The RUN Position And The Engine Off Refer to Wiring Diagrams Cell 12, for schematic and connector information. Normal Operation Under normal operation, the charging system warning indicator is on with the key on and the engine off. Possible Causes - Instrument cluster
- Powertrain control module (PCM)
| PINPOINT TEST E : THE CHARGING SYSTEM WARNING INDICATOR IS OFF WITH THE IGNITION SWITCH IN THE RUN POSITION AND THE ENGINE OFF | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | E1: CHECK THE CHARGING SYSTEM WARNING INDICATOR OPERATION | | | 1 Connect the diagnostic tool. | | | 2 Ignition switch in position II. | | | 3 Enter the following diagnostic mode: Instrument Cluster Active Commands. | | | 4 Using Active Commands, turn on the charging system warning indicator in the instrument cluster. | | | Is the charging system warning indicator on? Yes No REFER to Section 413-01 Instrument Cluster to diagnose the charging system warning indicator. TEST the system for normal operation. | | E2: CHECK FOR CORRECT PCM OPERATION | | | 1 Ignition switch in position 0. | | | 2 Disconnect all the PCM connectors. | | | 3 Check for | | | 4 Connect all the PCM connectors and make sure they seat correctly. | | | 5 Operate the system and verify the concern is still present. | | | Is the concern still present? Yes No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. | Pinpoint Test F: The Generator Is Noisy Refer to Wiring Diagrams Cell 12, for schematic and connector information. Normal Operation The generator is belt-driven by the engine accessory drive system. Possible Causes - Loose bolts/brackets
- Accessory drive belt
- Generator/pulley
| PINPOINT TEST F : THE GENERATOR IS NOISY | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | F1: CHECK FOR ACCESSORY DRIVE NOISE AND MOUNTING BRACKETS | | | 1 Ignition switch in position 0. | | | 2 | | | 3 Check the accessory mounting brackets and generator pulley for looseness or misalignment. | | | Is the accessory drive OK? Yes No | | F2: CHECK THE GENERATOR FOR EXCESSIVE ELECTRICAL NOISE | | | 1 Disconnect Generator C102c (2.3L), C102b (3.0L). | | | 2 Ignition switch in position III. | | | 3 With the engine running, determine if the generator is still noisy. | | | Is the noise still present? Yes No | | F3: CHECK THE GENERATOR FOR MECHANICAL NOISE | | | 1 Turn all the accessories off. With the engine running, use a stethoscope or equivalent listening device to probe the generator for unusual mechanical noise. | | | Is the generator the noise source? Yes No | Pinpoint Test G: Radio Interference Refer to Wiring Diagrams Cell 12, for schematic and connector information. Normal Operation The generator radio suppression equipment reduces interference transmitted through the speakers by the vehicle electrical system. Possible Causes - Generator
- In-vehicle entertainment system
| PINPOINT TEST G : RADIO INTERFERENCE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | G1: VERIFY THE GENERATOR IS THE SOURCE OF THE RADIO INTERFERENCE | NOTE:If the original equipment manufactured (OEM) audio unit has been replaced with an aftermarket unit, the vehicle may not pass this test. Return the vehicle to OEM condition before following this pinpoint test. | | | 1 Ignition switch in position III. | | | 2 Tune the radio to a station where the interference is present. | | | 3 Ignition switch in position 0. | | | 4 Disconnect Generator C102c (2.3L), C102b (3.0L). | | | 5 Ignition switch in position III. 6 With the engine running, determine if the interference is still present. | | | Is the interference present with the generator disconnected? Yes No | Component Tests Battery — Drain Testing WARNING: Do not attempt this test on a lead-acid battery that has recently been recharged. Explosive gases may cause personal injury. Failure to follow these instructions may result in personal injury. CAUTION: To prevent damage to the meter, do not crank the engine or operate accessories that draw more than 10A. NOTE: No factory-equipped vehicle should have more than a 50 mA (0.050 amp) draw. Check for current drains on the battery in excess of 50 mA (0.050 amp) with all the electrical accessories off and the vehicle at rest for at least 40 minutes. Current drains can be tested with the following procedure. NOTE: Many electronic modules draw 10 mA (0.010 amp) or more continuously. NOTE:Use an in-line ammeter between the negative battery post and its respective cable. NOTE: Typically, a drain of approximately one amp is attributed to an engine compartment lamp, glove compartment lamp or interior lamp staying on continually. Other component failures or wiring shorts are located by selectively pulling fuses to pinpoint the location of the current drain. When the current drain is found, the meter reading falls to an acceptable level. If the drain is still not located after checking all the fuses, it is due to the generator. NOTE: To accurately test the drain on a battery, an in-line ammeter must be used. Use of a test lamp or voltmeter is not an accurate method due to the number of electronic modules. - Make sure the junction box(es)/fuse panel(s) is accessible without turning on the interior lights or the underhood lights.
- Drive the vehicle at least 5 minutes and over 48 km/h (30 mph) to turn on and activate the vehicle systems.
- Allow the vehicle to sit with the key off for at least 40 minutes to allow the modules to time out/power down.
- Connect a fused jumper wire (30A) between the negative battery cable and the negative battery post to prevent modules from resetting and to catch capacitive drains.
- Disconnect the negative battery cable from the negative battery post without breaking the connection of the jumper wire.
-
NOTE: It is very important that continuity is not broken between the battery and the negative battery cable when connecting the meter. If this happens, the entire procedure must be repeated. Connect the battery tester between the negative battery cable and the post. The meter must be capable of reading milliamps and should have a 10 amp capability. -
NOTE: If the meter settings need to be switched or the test leads need to be moved to another jack, the jumper wire must be reinstalled to avoid breaking continuity. NOTE: Amperage draw varies from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference. NOTE: No factory-equipped vehicle should have more than a 50 mA (0.050 amp) draw. Remove the jumper wire. - Note the amperage draw. Draw varies from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference.
- If the draw is found to be excessive, remove the fuses from the smart junction box (SJB) one at a time and note the current reading. Do not reinstall the fuses until you have finished testing. To correctly isolate each of the circuits, all of the fuses may need to be removed and then install one fuse, note the amperage draw, remove the fuse and install the next fuse. Continue this process with each fuse.
- If the current draw is still excessive, remove the fuses from the battery junction box (BJB) one at a time and note the current drop. Do not reinstall the fuses until you have finished testing. To correctly isolate each of the circuits, all of the fuses may need to be removed, then install one fuse, note the amperage draw, remove the fuse and install the next fuse. Continue this process with each fuse. When the current level drops to an acceptable level after removing a fuse, the circuit containing the excessive draw has been located.
- Check the wiring diagrams for any circuits that run from the battery without passing through the BJB or the SJB. If the current draw is still excessive, disconnect these circuits until the draw is found. Also, disconnect the generator electrical connections if the draw cannot be located. The generator may be internally shorted, causing the current drain.
Generator On-Vehicle Tests CAUTION: To prevent damage to the generator, do not make the jumper wire connections except as directed. CAUTION: Do not allow any metal object to come in contact with the housing and the internal diode cooling fins with the key on or off. A short circuit may result and burn out the diodes. NOTE: Battery posts and cable clamps must be clean and tight for accurate meter indications. NOTE: Refer to the battery tester manual for complete directions for testing the charging system. - Turn off all lamps and electrical components.
- Place the transmission in NEUTRAL and apply the parking brake.
- Carry out the Load Test and No-Load Test according to the following component tests:
Generator On-Vehicle Tests — Load Test - Switch the tester to the ammeter function.
- Connect the positive and negative leads of the tester to the corresponding battery terminals.
- Connect the current probe to the generator B+ output terminal, circuit 38 (BK/OG) (2.3L), or circuit 36 (YE/WH) (3.0L).
Generator On-Vehicle Tests — No-Load Test - Switch the tester to the voltmeter function.
- Connect the voltmeter positive lead to the generator B+ terminal, circuit 38 (BK/OG) (2.3L), or circuit 36 (YE/WH) (3.0L), and the negative lead to ground.
- Turn all electrical accessories off.
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