PSM
Fault code 0538Reference voltage (PSM)
Diagnostic conditions
- Ignition on
- Internal PSM control module function test
Possible cause of fault
This fault is set if the voltage of terminal 15 to the PSM control module falls below '10.0 V'. The low voltage may be caused by the circuit of the sensors to be supplied, the power supply of terminal 15 of the PSM control module or because of an internal fault in the PSM control module. The possible causes are listed below:
- Short circuit to ground in the power supply circuit for sensors or PSM control module (electrical fault in electric circuit)
- Open circuit/contact resistance in terminal 15 circuit to PSM control module (electrical fault in electric circuit)
- Short circuit in PSM control module
Affected sensors:
- Combination sensor
- Speed sensors (all four)
Affected pins
PSM control module plug:
- Pin 4 'terminal 15 power supply input, via fuse F38, to fuse carrier at right of dashboard'
- Pin 6 'combination sensor power supply'
- Pin 34 'front right speed sensor signal wire'
- Pin 36 'rear left speed sensor signal wire'
- Pin 43 'rear right speed sensor signal wire'
- Pin 45 'front left speed sensor signal wire'
Diagnosis/troubleshooting PSM 0101
NOTE:
- If other fault codes are stored in the fault memory in addition to fault code '538', the circuit of the affected components must be checked for short circuits The diagnostic instructions for the stored fault codes must be observed for the test:
- If only fault code '538' is stored in memory, this indicates a short circuit in the PSM control module or in the terminal 15 circuit to the PSM control module, or an open circuit in the terminal 15 wire
NOTE:
Visual inspection: In the next troubleshooting section, please check first that the affected 'pins' on the PSM control module plug connection are neither damaged nor corroded. The wiring of the affected components must also be checked for external damage. Repair damaged or corroded 'pins' if possible, otherwise replace affected 'pins'. Repair or replace damaged wire.
