Bus and Diagnostic Communication

P1623

No Bus Data From TCM










Fault Symptoms
No bus communication with TCM.

Conditions
The following conditions apply:

Trionic:
- Engine Running
- TCM has previously been present on the bus at some time.
- No communication for 3 seconds

Diagnostic Help
Some of the following symptoms may be observed:
- DTC P1921 in TCM (if TCM can be contacted).
- Additional DTCs in Trionic (P1622).
- Engine will not start.
- Automatic transmission in limp-home (CHECK GEARBOX on)

Check Wiring Harness.
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostic tool during the test.