Fault code 9121: Diagnosis/troubleshooting

DIAGNOSIS/TROUBLESHOOTING - FAULT CODE 9121

Work instruction			Display OK	If not OK
1	Check output voltage of the instrument cluster	Disconnect wire to Pin 1 of the oil pressure switch. Switch ignition on. Measure voltage between pin 1 and ground.	approx. 5 V Step 5	Step 2
2	Check wire between instrument cluster and oil pressure switch for short to ground	Switch off ignition Remove plug A from the instrument cluster Measure resistance between plug A on instrument cluster pin 13 and ground	Step 3	Repair wiring harness -> End
3	Check wire between instrument cluster and oil pressure switch for short circuit to B+	Switch on ignition Measure voltage between plug A on instrument cluster pin 13 and positive	0 V Step 4	Repair wiring harness -> End
4	Check wire between instrument cluster and oil pressure switch for open circuit	Switch off ignition Measure resistance on plug A on the instrument cluster pin 13 and plug on oil pressure switch pin 1.	< 5 Step 5	Repair wiring harness. -> End
5	Connect the plug on instrument cluster A pin 13 and the plug on oil pressure switch again. Delete fault memory and check whether the fault appears again. Replace oil pressure switch.		-> End	Step 6
6	Replace instrument cluster		-> End