TCM E39 / U0121 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Message appears in display.
TCS/ESP was Missing on Bus
Fault symptom
Message appears in display.
On-board diagnosis
Type of diagnosis:
Enable criteria:
| Voltage is over 9V but under 16V |
| Ignition on for at least 5 s. |
Fault criteria:
| No communication with TCS/ESP |
System reaction to a fault:
Checking the wiring harness
Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.
Diagnostic help
In order to read DTC from Trionic TCM, communication with CIM is required. If the DTC is stored and read with the diagnostic instrument, it indicates intermittent bus-lead fault.
