Test F: The Powertrain Control Module (PCM) Does Not Respond To The Diagnostic Tool
PINPOINT TEST F: THE POWERTRAIN CONTROL MODULE (PCM) DOES NOT RESPOND TO THE DIAGNOSTIC TOOLF1-F2:
F2-F3:
Normal Operation
The PCM communicates with the diagnostic tool through the high speed controller area network (CAN), circuits 1908 (WH) and 1909 (BK). The high speed CAN is not designed to operate under single point fault conditions. If either circuit is shorted to voltage or the high speed CAN data plus is shorted to ground, module-to-module and module-to-tester communication is not possible. If the high speed CAN data minus is shorted to ground or an open exists on either bus line, module-to-module and module-to-tester communication is marginal at best. The high speed CAN bus may remain operational when one of the two termination resistors are not present. The PCM and instrument cluster share communications network termination responsibilities with the use of a split termination resistor in each module. Check circuits 1908 (WH) and 1909 (BK) 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
- high speed CAN circuit 1908 (WH) or 1909 (BK) open
- PCM C175b
- PCM