Test L: The Electronic Automatic Temperature Control (EATC) Module Does Not Respond To The Scan Tool

PINPOINT TEST L: THE ELECTRONIC AUTOMATIC TEMPERATURE CONTROL (EATC) MODULE DOES NOT RESPOND TO THE SCAN TOOL

Normal Operation
The electronic automatic temperature control (EATC) module communicates with the scan tool through the medium speed controller area network (MS-CAN). Circuits VDB06 (GY/OG) (MS-CAN +) and VDB07 (VT/OG) (MS-CAN -) provide the network connection to the EATC module. The EATC module shares the MS-CAN network with the instrument cluster, smart junction box (SJB), audio unit, satellite radio receiver, front control interface module (FCIM) and front display interface module (FDIM). Voltage to the EATC module is provided by circuit SBP15 (WH/RD) and circuit CBP37 (WH). Ground is provided by circuit GD114 (BK/BU).

NOTE: The electronic manual temperature control (EMTC) module does not communicate with the scan tool.

This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- EATC module

L1:

L2-L3:

L4: