Test B: The Powertrain Control Module (PCM) Does Not Respond to the Diagnostic Tool

PINPOINT TEST B: THE POWERTRAIN CONTROL MODULE (PCM) DOES NOT RESPOND TO THE DIAGNOSTIC TOOL

B1-B2:

Normal Operation
The PCM communicates with the diagnostic tool through the controller area network (CAN), circuits 4-EC7 (GY/RD) and 5-EC7 (BU/RD). Check circuits 4-EC7 (GY/RD) and 5-EC7 (BU/RD) between the PCM C175b 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 one of the high speed CAN circuits, damage to the DLC C251, damage to the PCM C175b, or a problem in an in-line connector.

Possible Causes
- CAN circuit 4-EC7 (GY/RD) open
- CAN circuit 5-EC7 (BU/RD) open
- PCM C175b
- PCM
- DLC C251