Pinpoint Test 12: The HVAC Module Does Not Respond To The Scan Tool

PINPOINT TEST 12: THE HVAC MODULE DOES NOT RESPOND TO THE SCAN TOOL - HYBRID

Normal Operation

The HVAC module communicates with the scan tool through the medium speed controller area network (MS-CAN). Circuits (GY/O) (MS-CAN +) and (VT/O) (MS-CAN -) provide the network connection to the HVAC module. The HVAC module shares the MS-CAN with the instrument cluster (IC), smart junction box (SJB), audio control module (ACM), satellite digital audio receiver system (SDARS) module, front controls interface module (FCIM) and front display interface module (FDIM). Voltage to the HVAC module is provided by circuits (W/R) and (W). Ground is provided by circuit (B/L).

Possible Causes
- Fuse
- Wiring, terminals or connectors
- HVAC module

Diagnostic Procedure

CAUTION:Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.
NOTE:Failure to disconnect the battery when instructed will result in false resistance readings. See Battery Disconnect.