Normal Operation
The PCM communicates with the diagnostic tool through the high speed controller area network (CAN), circuits VDB04 (WH/BU) and VDB05 (WH).
Check the high speed CAN circuits VDB04 (WH/BU) and VDB05 (WH) 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.