E39 / U0121 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: Cruise control not working.
Message appears in display.
TCS/ESP Missing on Bus
Fault symptom
Cruise control not working.
Message appears in display.
On-board diagnosis
Type of diagnosis:
Enable criteria:
| Battery voltage must be between 10 - 18 V. |
Fault criteria:
| No communication with TCS/ESP |
Dependent:
Fault handling:
| (See section Fault handling III, "Other emission-related components and functions" for more information.) |
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
Diagnosis regards:
| Electrical fault on bus leads or in the component. |
| See fault diagnosis for the TCS/ESP DTC in question and bus fault diagnosis. |
Functions in the diagnostic tool related to the fault:
| Response test, under "All/Bus" menu. |
| Read / Reset Bus Configuration |
| Read / Clear Bus Off Counter |
