Initial Inspection and Diagnostic Overview
INSPECTION AND VERIFICATIONWARNING:
- 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.
- 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.
- When lifting a plastic-cased 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 fuse links.
- 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 DTCs set while following any specific pinpoint test. After the completion of any test, be sure to clear all codes in the PCM.
- All voltage measurements are referenced to the negative (-) battery post unless otherwise specified.
1. Verify the customer concern.
Visual Inspection Chart:
2. Visually inspect for signs of mechanical and electrical damage.
3. If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
4. Verify the battery condition. Refer to Battery.
5. 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.
6. 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.
7. If the concern remains after the inspection, connect the diagnostic tool to the data link connector (DLC) located under the instrument panel and select the vehicle to be tested from the diagnostic tool menu. If the vehicle selection cannot be entered:
- check that the diagnostic card is correctly installed.
- check the connections to the vehicle.
- check the ignition switch position. If the diagnostic tool still does not allow the vehicle selection to be entered, refer to the diagnostic tool manual.
8. Carry out the diagnostic tool data link test. If the diagnostic tool reponds with:
- CAN+, CAN- circuit fault; all electronic control units no response/not equipped, refer to Information Bus (Module Communications Network).
- No response/not equipped for powertrain control module (PCM), refer to Computers and Control Systems.
- System passed, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the self-test diagnostics for the PCM.
9. If the DTCs retrieved are related to the concern, go to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index or the Instrument Cluster Diagnostic Trouble Code (DTC) Index to continue diagnostics. For all other DTCs, refer to Information Bus (Module Communications and Network). Powertrain Control Module Diagnostic Trouble Code (DTC) Index Instrument Cluster Diagnostic Trouble Code (DTC) Index
10. If no DTCs related to the charging system are retrieved, GO to Symptom Chart to continue diagnosis. Symptom Related Diagnostic Procedures
NOTE: DTC P1246 can be set by the loss of the communication lines, GEN MON circuit 3204 (GN/OG) and/or GEN COM circuit 904 (LG/RD). The generator warning indicator will then illuminate until the engine is operated at 2000 rpm momentarily; at which time the generator will self-excite, the charging system warning indicator will turn off and the generator will operate in default mode (13.5 volts) until the engine is turned off.