Fault code 4: Diagnosis/Troubleshooting

Diagnosis/Troubleshooting (FAULT CODE 4)

Work instruction			Display OK	If not OK
1	Visual inspection	Visual inspection of the sensor linkage Visual inspection of the plastic holder for the sensor	"Continue with 2"	Repair linkage and/or plastic holder "End"
2	Check 5 V supply voltage of the sensor	Switch off ignition Pull plug off the angle sensor for HBA, rear Switch ignition on Measure voltage between pin 5 of the sensor plug and ground	approx. 5 V "Continue with 3"	"Continue with 5"
3	Check ground lead of the sensor	Measure voltage between pin 5 and pin 1 of the sensor plug	approx. 5 V "Continue with 4"	"Continue with 8"
4	Check signal wire of the sensor	In the PST2 menu item Actual values, select Sensor voltage, spring travel 1 (rear) Connect a jumper to pins 4 and 5 of the sensor plug	approx. 5 V "Continue with 12"	"Continue with 9"
5	Check 5 V supply lead for short to ground	Switch off ignition Pull plug off the control module for HBA Measure resistance between the plug on the control module for HBA pin 14 and ground	"Continue with 6"	Repair wiring harness "End"
6	Check 5 V supply lead for short to B+	Switch ignition on Measure voltage between the plug on the control module for HBA pin 14 and ground	0 V "Continue with 7"	Repair wiring harness "End"
7	Check 5 V supply lead for open circuit	Switch off ignition Measure resistance between the plug on the control module for HBA pin 14 and the plug on the angle sensor for HBA, rear, pin 5	< 5 "Continue with 13"	Repair wiring harness "End"
8	Check ground lead of the sensor for open circuit	Measure resistance between the plug on the control module for HBA pin 17 and the plug on the angle sensor for HBA pin 1	< 5 "Continue with 13"	Repair wiring harness "End"
9	Check signal wire of the sensor for short to ground	Pull plug off the control module for HBA Measure resistance between the plug on the control module for HBA pin 13 and ground Measure resistance between the plug on the control module for HBA pin 13 and pin 17	"Continue with 10"	Repair wiring harness "End"
10	Check signal wire of the sensor for short to B+	Switch ignition on Measure voltage at the plug on the control module for HBA pin 13 and ground	0 V "Continue with 11"	Repair wiring harness "End"
11	Check signal wire of the sensor for open circuit	Switch off ignition Measure resistance between the plug on the control module for HBA pin 13 and the plug on the angle sensor for HBA, rear, pin 5	< 5 "Continue with 13"	Repair wiring harness "End"
12	Replace angle sensor for HBA, rear
13	Replace control module for HBA