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

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


E1:






E1-E3:






E4-E5:






Normal Operation
The EATC module communicates with the scan tool through the standard corporate protocol (SCP) communication network. Circuits 914 (TN/OG) (SCP +) and 915 (PK/LB) (SCP-) provide the network connection to the EATC module. The EATC shares the SCP network with the lighting control module (LCM), the driver door module (DDM), the overhead console and the instrument cluster. Voltage for the EATC module is provided by circuits 1812 (BR/WH) and 1566 (RD/YE). Circuit 57 (BK) provides ground.

Possible Causes
- Fuse
- Circuit 57 (BK) open
- Circuit 914 (TN/OG) open (SCP +)
- Circuit 915 (PK/LB) open (SCP -)
- Circuit 1566 (RD/YE) open
- Circuit 1812 (BR/WH) open
- EATC module