Pinpoint Tests AA: The RETM Does Not Respond To The Scan Tool

Communications Network

Pinpoint Test AA: The RETM Does Not Respond To The Scan Tool

Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. Diagrams By Number

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

Normal Operation

The Rear Entertainment Module (RETM) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN).

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- RETM

PINPOINT TEST AA: THE RETM DOES NOT RESPOND TO THE SCAN TOOL

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

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AA1 CHECK THE RETM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

- Ignition OFF.
- Disconnect: RETM C2949a .
- Ignition ON.
- Measure the voltage between the RETM C2949a-13, circuit SBP14 (BN/RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to AA2.

No
VERIFY the Smart Junction Box (SJB) fuse 14 (10A) is OK. If OK, REPAIR the circuit in question. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the network test with the scan tool. Diagrams By Number

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AA2 CHECK THE RETM GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.
- Measure the resistance between the RETM C2949a-1, circuit GD114 (BK/BU), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to AA3.

No
REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.

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AA3 CHECK THE MS-CAN CIRCUITS BETWEEN THE RETM AND THE DLC FOR AN OPEN

- Disconnect: RETM C2949b .
- Measure the resistance between the RETM C2949b-14, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.




- Measure the resistance between the RETM C2949b-15, circuit VDB07 (VT/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.




- Are the resistances less than 5 ohms?

Yes
GO to AA4.

No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.

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AA4 CHECK FOR CORRECT RETM OPERATION

- 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 verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new RETM. REFER to Information and Entertainment Systems Rear Entertainment Module (RETM). CLEAR the DTCs. REPEAT the network test with the scan tool.

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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