Pinpoint Test B: DTC B1318
NOTE:
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE:
Failure to disconnect the battery when instructed will result in false resistance readings. Refer to
BATTERY, BATTERY MOUNTING SYSTEM & BATTERY CABLES
article.
- B1 RECHECK THE GEM DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: GEM Self-Test.
- Clear the DTCs. Repeat the GEM self-test.
- Is DTC B1318 still present?
- Yes: Go to B2.
- No: The system is operating normally at this time. The DTC may have been set previously during battery charging or while jump starting the vehicle.
- B2 CHECK FOR CHARGING SYSTEM DTCs IN THE PCM
- Enter the following diagnostic mode on the scan tool: PCM Self-Test.
- Retrieve the continuous memory DTCs from the PCM.
- Is DTC P0620:00, P0625:00, P0626:00 or P065B:00 set in the PCM?
- Yes: REFER to CHARGING SYSTEM article.
- No: Go to B3.
- B3 CHECK THE BATTERY CONDITION AND STATE OF CHARGE
- Ignition OFF.
- Check the battery condition and verify the battery is fully charged. Refer to BATTERY, BATTERY MOUNTING SYSTEM & BATTERY CABLES article.
- Is the battery OK and fully charged?
- Yes: Go to B4.
- No: REFER to CHARGING SYSTEM article.
- B4 CHECK THE GEM VOLTAGE SUPPLY
- Measure and record the voltage at the battery.
- Disconnect: GEM C201A.
- Ignition ON.
- Measure the voltage between the GEM C201A-10, circuit 15-DK20 (GN/OG), harness side and ground.
- Is the voltage within 0.2 volt of the recorded battery voltage?
- Yes: Go to B5.
- No: REPAIR the circuit for high resistance. CLEAR the DTC. REPEAT the self-test.
- B5 CHECK THE GEM GROUND CIRCUIT
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Disconnect: GEM C201D.
- Measure the resistance between the GEM C201D-3, circuit 31-DK20 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
- Yes: CONNECT the negative battery cable. Go to B6.
- No: REPAIR the circuit for high resistance. CONNECT the negative battery cable. TEST the system for normal operation.
- B6 CHECK FOR CORRECT GEM OPERATION
- Disconnect all the GEM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the GEM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new GEM . REFER to GENERIC ELECTRONIC MODULE (GEM) in this service information. TEST the system for normal operation.
- No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.