Test K: No Controller Area Network (CAN) Communication
PINPOINT TEST K: NO CONTROLLER AREA NETWORK (CAN) COMMUNICATIONK1:
K1-K3:
K3-K5:
K5-K7:
K7-K9:
K9-K11:
K11-K14:
K15-K18:
Normal Operation
The powertrain control module (PCM), anti-lock brake system (ABS) module, electronic automatic temperature control (EATC) module, tire pressure monitoring system module, and the instrument cluster communicate with the diagnostic tool through the CAN circuits 3125 (RD/YE) and 3126 (TN/YE). 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 with degraded performance. If a module is lost due to internal concerns, communications can continue to all other modules. Check circuits 3125 (RD/YE) and 3126 (TN/YE) between the PCM C175b, tire pressure monitoring system module C3183, ABS module C155, EATC module C228b, instrument cluster C220b, 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 3125 (RD/YE) and 3126 (TN/YE), damage to the DLC C251, damage to one of the network modules, or a problem in the in-line connectors or an internal problem with one of the networked modules. If, after individual checks of each circuit leading to a module show resistance values less than 5 ohms and no in-line connector issues present, the diagnostic tool data link test must be run with the module in question disconnected. If the diagnostic tool data link test passes with the module in question disconnected it is the source of the concern and should be removed and a new module installed.
Possible Causes
- circuit 3125 (RD/YE) short to voltage, short to ground or open
- circuit 3126 (TN/YE) short to voltage, short to ground or open
- DLC C251
- ABS module
- PCM
- EATC module
- instrument cluster
- tire pressure monitoring system module (if equipped)