Test J: The Dual Electronic Automatic Temperature Control (DEATC) Module Does Not Respond To The Diagnostic Tool

PINPOINT TEST J: THE DUAL ELECTRONIC AUTOMATIC TEMPERATURE CONTROL (DEATC) MODULE DOES NOT RESPOND TO THE DIAGNOSTIC TOOL

J1-J2:

Normal Operation
The DEATC module communicates with the diagnostic tool through the standard corporate protocol (SCP) communications network circuits 914 (TN/OG) and 915 (PK/LB). If one of the communications network circuits become shorted to ground or voltage, or if some but not all termination resistors are lost, communications can continue. Check circuits 914 (TN/OG) and 915 (PK/LB) between the DEATC module C228b 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 circuit 914 (TN/OG) or 915 (PK/LB), damage to the DLC C251, or damage to the DEATC module C228b.

Possible Causes
- SCP communications network circuit 914 (TN/OG) open
- SCP communications network circuit 915 (PK/LB) open
- DLC C251
- DEATC module
- DEATC module C228b