Test C: The Powertrain Control Module (PCM) Does Not Respond to the Diagnostic Tool
PINPOINT TEST C: THE POWERTRAIN CONTROL MODULE (PCM) DOES NOT RESPOND TO THE DIAGNOSTIC TOOLC1:
C1-C2:
Normal Operation
The PCM communicates with the diagnostic tool through the standard corporate protocol (SCP) communication network circuits 914 (TN/OG) and 915 (PK/LB). If one of the bus wires becomes shorted to ground or voltage, or if some but not all termination resistors are lost, communications can continue at a degraded level. Check SCP circuits 914 (TN/OG) and 915 (PK/LB) between the PCM C175 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 either an open in the SCP network circuits, damage to the DLC C251, damage to the PCM C175, or a problem in the in-line connector.
Possible Causes
- SCP circuits 914 (TN/OG) and 915 (PK/LB) open
- DLC C251
- PCM