C0121 01 (ESP - Electronic Stability Program)
C0121 01
Valve Relay Does Not Open
Fault symptom
- ABS warning lamp on
- Messages shown in SID.
- Steering column lock not working.
On-board diagnosis
Type of diagnosis:
- Upon start-up.
Enable criteria:
- Ignition ON.
Fault criteria:
- When voltage on output exceeds 2 V.
System reaction to a fault:
- No ABS function
- No TCS/ESP function
Diagnostic help
Diagnosis regards:
- Electrical fault in connecting leads or component.
Functions in the diagnostic tool related to the fault:
Test value:
- Valve Feed
Activation:
- Valve Feed
(See also description of readings/activations in diagnostic tool)