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

Information and Entertainment System

Pinpoint Tests

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

Refer to Wiring Diagram Set 130, Audio System/Navigation for schematic and connector information. Diagrams By Number

Normal Operation
- DTC B1318 (Battery Voltage Low) - set by the Rear Entertainment Module (RETM) as a continuous or on-demand DTC if the RETM detects low battery voltage below 10 volts for greater than 10 seconds on circuit SBP03 (BU/RD).

This pinpoint test is intended to diagnose the following:

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



PINPOINT TEST Z: DTC B1318 (RETM)

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. Refer to Battery.

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Z1 RECHECK THE RETM DTCs


- Clear the RETM DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 10 seconds.
- Repeat the RETM self-test.
- Is DTC B1318 still present?

Yes
GO to Z2.

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

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Z2 CHECK FOR CHARGING SYSTEM DTCs IN THE PCM


- Retrieve the continuous memory DTCs from all modules.
- Is DTC P0620, P0622, P0625, P0626 or P065B set in the PCM?

Yes
REFER to Charging System.

No
GO to Z3.

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Z3 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 Z4.

No
REFER to Battery.

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Z4 CHECK THE RETM VOLTAGE SUPPLY


- Ignition OFF.
- Measure and record the voltage at the battery.
- Disconnect: RETM.
- Ignition ON.
- Measure the voltage between the RETM C9029-16, circuit SBP03 (BU/RD), harness side and ground.




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

Yes
GO to Z5.

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

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Z5 CHECK THE RETM GROUND CIRCUIT


- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the RETM C9029-1, circuit GD103 (BK/BU), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to Z6.

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

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Z6 CHECK FOR CORRECT RETM OPERATION


- 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.
- 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.

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