Pinpoint Test A: No Communication With the Liftgate/Trunk Module (LTM)
Luggage Compartment Lid
Pinpoint Test A: No Communication With the Liftgate/Trunk Module (LTM)
Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 113, Luggage Compartment for schematic and connector information. Diagrams By Number
Normal Operation
The Liftgate/Trunk Module (LTM) receives voltage from the Battery Junction Box (BJB) through circuit 1190 (YE/BK), the Central Junction Box (CJB) through circuit 1524 (DB) and through circuit 640 (RD/YE). The LTM grounds through circuits 57 (BK) and 676 (PK/OG). The LTM receives a voltage signal from the Driver Door Module (DDM) when either the button on the driver door trim panel, the Remote Keyless Entry (RKE) keypad or the RKE transmitter is pressed (twice on the RKE transmitter).
The LTM receives vehicle speed information from the PCM. The LTM will shut down the system if vehicle speed is above 5 km/h (3 mph). For diagnostics, the module uses the ISO network. Whenever battery voltage is lost to the LTM, luggage compartment lid motor or the luggage compartment lid closing motor, the system must be initialized.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Wiring, terminals or connectors
- LTM
NOTE: ISO 9141 circuit 70 provides the communication link for this module. This module or another module(s) (must use circuit 70, also) may be shorted internally causing a loss of communication. First, attempt to communicate with another module(s) that uses circuit 70 as its communication link. If communication cannot be established with another module(s) on circuit 70, refer to Module Communications Network Testing and Inspection.
PINPOINT TEST A: NO COMMUNICATION WITH THE LIFTGATE/TRUNK MODULE (LTM)
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use correct probe adapter(s) may damage the connector.
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A1 CHECK THE VOLTAGE TO THE MODULE
- Ignition OFF.
- Disconnect: LTM C4081c, C4081d.
- Ignition ON.
- Measure the voltage between LTM C4081d-4, circuit 1190 (YE/BK), harness side and ground; and between LTM C4081c-6, circuit 640 (RD/YE), harness side and ground; and between LTM C4081c-17, circuit 1524 (DB), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A2.
No
VERIFY BJB fuse 108 (40A) and CJB fuses 8 (10A) and 19 (7.5A) are OK. If OK, REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Diagrams By Number
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A2 CHECK THE GROUND TO THE MODULE
- Ignition OFF.
- Measure the resistance between LTM C4081d-3, circuit 57 (BK), harness side and ground; and between LTM C4081c-12, circuit 676 (PK/OG), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
To continue diagnosis of the LTM, REFER to Module Communications Network Testing and Inspection.
No
REPAIR the circuit(s). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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