Pinpoint Test AT: DTC B1318

Seats

Pinpoint Test AT: DTC B1318

Normal Operation

The Driver Seat Module (DSM) monitors the voltage from the battery to determine if it goes above or below specific thresholds and sets DTC B1318 in continuous memory if the DSM (Driver Seat Module) detects low battery voltage below 10 volts.

- DTC B1318 (Battery Voltage Low)- a continuous memory DTC that sets when the DSM (Driver Seat Module) detects battery voltage below 10 volts.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- High circuit resistance

- DSM (Driver Seat Module)

PINPOINT TEST AT : DTC B1318

NOTICE: 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.

AT1 RECHECK THE DSM (Driver Seat Module) DTCs

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: DSM (Driver Seat Module) Self-Test.

- Clear the DTCs. Repeat the DSM (Driver Seat Module) self-test.

Is DTC B1318 still present?

Yes
GO to AT2.

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.

AT2 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, P0625, P0626 or P065B set in the PCM?

Yes
REFER to Charging System.

No
GO to AT3.

AT3 CHECK THE BATTERY CONDITION AND STATE OF CHARGE

- Ignition OFF.

- Check the battery condition and verify the battery is fully charged.

Is the battery OK and fully charged?

Yes
GO to AT4.

No
REFER to Charging System.

AT4 CHECK THE DSM (Driver Seat Module) VOLTAGE SUPPLY

- Measure and record the voltage at the battery.

- Disconnect: DSM (Driver Seat Module) C341A.

- Disconnect: DSM (Driver Seat Module) C341B.

- Ignition ON.

- Measure the voltage between the DSM (Driver Seat Module) C341A-1, circuit CBX05 (VT/RD), harness side and ground.





- Measure the voltage between the DSM (Driver Seat Module) C341B-1, circuit CBX03 (BU/RD), harness side and ground.





Is the voltage within 0.2 volt of the recorded battery voltage?

Yes
GO to AT5.

No
REPAIR the circuit for high resistance. CLEAR the DTC. REPEAT the self-test.

AT5 CHECK THE DSM (Driver Seat Module) GROUND CIRCUIT

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- Measure the resistance between the DSM (Driver Seat Module) C341A-2, circuit GD906 (BK/GY), harness side and ground.





- Measure the resistance between the DSM (Driver Seat Module) C341B-24, circuit GD905 (BK/GN), harness side and ground.





Is the resistance less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to AT6.

No
REPAIR the circuit for high resistance. CONNECT the negative battery cable. TEST the system for normal operation.

AT6 CHECK FOR CORRECT DSM (Driver Seat Module) OPERATION

- Disconnect the DSM (Driver Seat Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect the DSM (Driver Seat Module) 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 DSM (Driver Seat Module). REFER to Driver Seat Module (DSM) . 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.