Pinpoint Test D: The HVAC Module Illumination Is Inoperative/Does Not Dim

Instrument Cluster and Panel Illumination

Pinpoint Tests

Pinpoint Test D: The HVAC Module Illumination Is Inoperative/Does Not Dim

Normal Operation

The Lighting Control Module (LCM) communicates the requested level of backlighting intensity to the HVAC module through the Standard Corporate Protocol (SCP) network.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- HVAC module
- LCM



PINPOINT TEST D: THE HVAC MODULE ILLUMINATION IS INOPERATIVE/DOES NOT DIM

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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D1 CHECK THE HVAC MODULE NETWORK COMMUNICATION


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Network Test.
- Carry out the network test.
- Does the scan tool respond with no communication with the HVAC module?

Yes
REFER to Information Bus.

No
INSTALL a new HVAC module. TEST the system for normal operation.

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