Fault code 1331: Diagnosis/troubleshooting
NOTE:
Visual inspection: In the next troubleshooting section, please check first that the affected pins on the driver's door control unit plug connection are neither damaged nor corroded. The wiring and plugs of the affected components must also be checked for external damage and proper contact. Repair damaged or corroded pins if possible, otherwise replace affected pins. Repair or replace damaged wires.
NOTE:
Sporadic faults: In the event of faults that occur sporadically, the wiring positions that are linked to moving parts on and in the vehicle must be checked for each system. Various statuses that can cause faults must be simulated with the help of the wiring diagram.
NOTE:
Battery voltage: A battery voltage of between 11.4 and 14.5 V is required for the following troubleshooting procedure. This must be checked and provided, if necessary. On the vehicle electrical system, the voltage to the fuse (input side) must be guaranteed.
NOTE:
In the wiring harness there is a connector that must be included in the checks.
WORK INSTRUCTION CHART
| Work instruction | Display OK | If not OK | ||
|---|---|---|---|---|
| 1 | Check fault type using [F8] | 'Below lower limit' Go to step 2 'Above upper limit' Go to step 5 'No signal/communication' Go to step 6 'faulty' Go to step 7 |
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| 2 | Check fuses | Check fuses for continuity
|
Go to step 3 | Replace fuse and remedy the cause, if necessary → End |
| 3 | Check voltage supply. |
|
11.4 to 14.5 V Go to step 4 |
Check, and repair if necessary, pin 1 of the connector. Repair line → End |
|
Check, and repair if necessary, pin 3 of the connector. Repair line → End |
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| 4 | Check ground supply |
|
< 5 Ω Go to step 7 |
Check, and repair if necessary, pin 4 of the connector. Check, and repair if necessary, the line and ground pin 21 → End |
| 5 | Check generator | → End | ||
| 6 | Continue troubleshooting in the chapter 'Checking instructions/CAN data bus' | → End | ||
| 7 | Replace driver's door control unit | → End | ||