Test G: The Electronic Automatic Temperature Control (EATC) Module Does Not Respond to the Diagnostic Tool

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

G1-G2:

G2-G3:

Normal Operation
The EATC module communicates with the diagnostic tool through the standard corporate protocol (SCP) communication network, circuits 914 (TN/OG) and 915 (PK/LB). Check circuits 914 (TN/OG) and 915 (PK/LB) between the EATC module C228a and the data link connector (DLC) C251. The total resistance values must not be more than 5 ohms. If the resistance is more than 5 ohms, there is an open in the SCP network circuits, damage to the DLC C251, the EATC module C228a, or a problem in the in-line connectors.

Possible Causes
- SCP circuits 914 (TN/OG) or 915 (PK/LB) open
- EATC module C228a
- EATC module