Diagnostic Procedures
1. Checking Additional Diagnostic Trouble Codes
Obtain readouts of the diagnostic trouble codes.
Any other diagnostic trouble codes?
NO
Go to step 4
YES
Go to step 2
2. Checking Additional Diagnostic Trouble Codes
Diagnosis for this Fault Code is complete.
Continue fault diagnosis for the Diagnostic Trouble Code concerned.
3. Checking The Battery Voltage
Part 1 Of 2:
Part 2 Of 2:
Take a voltage reading.
The reading should be 12 V - 14 V
Checking the wiring harness.
- Jiggle the leads and in-line connectors at several places and indifferent directions to several intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
Is the function correct?
NO
Go to step 5
YES
Go to step 8
4. Checking The Battery Voltage
Check the battery.
When check is complete
Refer to step 5
5. Final Check
Clear the diagnostic trouble codes in all systems.
Carry out a drive cycle.
- Drive the car at varying engine loads and engine rpm for five minutes.
Evaluate the drive cycle:
Check that the diagnostic trouble code has not recurred
Is the function correct?
NO
Go to step 7
YES
Go to step 6
6. Final Check
The steps taken to rectify the fault were correct.
Diagnosis is complete
7. Final Check
Diagnosis for this fault code is complete.
Refer to Procedures, Before Changing A Control Module.
8. Check The Control Module's Power Supply
Unplug the control module
Control module, TCM 502
Part 1 Of 2:
Part 2 Of 2:
Connect test lamp 86 11 857 to pin 16 of the female connector and a good grounding point.
Jiggle the leads and in-line connector at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
The test lamp should light.
Is the function correct.
NO
Go to step 9
YES
Go to step 10
9. Rectifying The Lead
Repair or replace the lead between pin 16 of the control module and fuse 34.
When repair is complete:
Go to step 5
10. Check The Control Module's Power Supply
Part 1 Of 2:
Part 2 Of 2:
Connect the test lamp 86 11 857 to pin 1 of the female connector and a good grounding point.
Jiggle the leads and in-line connector at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
The test lamp should light.
Is the function correct.
NO
Go to step 11
YES
Go to step 12
11. Rectifying The Lead
Repair or replace the lead between pin 16 of the control module and fuse 34.
When repair is complete:
Go to step 5
12. Check The Control Module's Power Supply
Part 1 Of 2:
Part 2 Of 2:
Connect the test lamp 86 11 857 to pin 31 of the female connector and a good grounding point.
Jiggle the leads and in-line connector at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
The test lamp should light.
Is the function correct.
NO
Go to step 13
YES
Go to step 14
13. Rectifying The Lead
Repair or replace the lead between pin 31 of the control module and grounding point G38.
When repair is complete:
Go to step 5
14. Check The Control Module's Power Supply
Part 1 Of 2:
Part 2 Of 2:
Connect the test lamp 86 11 857 to pin 31 of the female connector and a good grounding point.
Jiggle the leads and in-line connector at several places and in different directions to reveal intermittent breaks and short circuits in the wiring harness. Observe the multimeter, test lamp or diagnostic tool while doing this.
The test lamp should light.
Is the function correct.
NO
Go to step 15
YES
Go to step 5
15. Rectifying The Lead
Repair or replace the lead between pin 32 of the control module and grounding point G38.
When repair is complete:
Go to step 5