Pinpoint Test AH: DTC B1318 (Rear Entertainment Module (RETM))

Information and Entertainment System

Pinpoint Tests

Pinpoint Test AH: DTC B1318 (Rear Entertainment Module (RETM))

Normal Operation
- DTC B1318 (Battery Voltage Low) - set by the Rear Entertainment Module (RETM) when the supply voltage falls below 10 volts for at least 10 seconds during normal operation.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- High circuit resistance
- RETM



PINPOINT TEST AH: DTC B1318 (RETM)

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.

-------------------------------------------------
AH1 RECHECK THE RETM DTCs


- Ignition ON.
- Clear the RETM DTCs.
- Wait at least 15 seconds.
- Repeat the RETM self-test.
- Is DTC B1318 still present?

Yes
GO to AH2.

No
The system is operating correctly at this time. The DTC may have been set due to a previous low battery voltage condition.

-------------------------------------------------
AH2 CHECK FOR CHARGING SYSTEM DTCs IN THE PCM


- Retrieve the continuous DTCs from all modules.
- Is DTC P0620, P0622, P0625 or P065B set in the PCM?

Yes
REFER to Charging System.

No
GO to AH3.

-------------------------------------------------
AH3 CHECK THE BATTERY CONDITION AND STATE OF CHARGE


- Check the battery condition and verify that the battery is fully charged. Refer to Battery.
- Is the battery OK and fully charged?

Yes
GO to AH4.

No
REFER to Battery.

-------------------------------------------------
AH4 CHECK THE RETM VOLTAGE SUPPLY


- Ignition OFF.
- Measure and record the voltage at the battery.
- Disconnect: RETM C949 .
- Ignition ON.
- Measure the voltage between the RETM C949-16, circuit SBP03 (BU/RD), harness side and ground.




- Is the voltage at the RETM within 0.2 volt of the recorded battery voltage?

Yes
GO to AH5.

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

-------------------------------------------------
AH5 CHECK THE RETM GROUND CIRCUITS


- Ignition OFF.
- Disconnect: Negative Battery Cable .
- Measure the resistance between the RETM C949-1, circuit GD143 (BK/VT), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to AH6.

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

-------------------------------------------------
AH6 CHECK FOR CORRECT RETM OPERATION


- Ignition OFF.
- Connect: Negative Battery Cable .
- Disconnect the RETM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the RETM connector and make sure it seats correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?

Yes
INSTALL a new RETM. REFER to Rear Entertainment Module (RETM) Service and Repair. 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.

-------------------------------------------------