Footwell module error - headlights trigger door open sign when driving

Nastaliq said:

Nastaliq said:

the footwell module is placed in a place where it can get wet from car shampooing, and the connectors can be corroded, but also water can get into the wiring.
what are you using for diagnostics?

1. A second hand module must be matched and coded to your car. you need ISTA for this. you might also need to re-fresh your cars i-level or i-step, older firmware can misinterpret signals.
2. Electrical load from headlights changes the system voltage and can expose weak grounds or alternator fluctuation in current supply. A weak ground is a very obvious thing if the footwell module is cooked. Ground connections get corroded and you get a shit ground connection. clean all grounds in the footwell properly and spray with electrical contact cleaner then torque down properly. I have seen grounds tightened so hard, that the wires crimped out and had weak contacts. The nut looked like Thor tightened it, but the wires were loose
3. Check for >0.3 V across the battery at idle with lights on; if higher, I suspect alternator diodes will need to be checked, less commonly happening, but still possible. 9 out of 10 times its weak contacts to ground.
4. Finally check the door latch microswitch/latch. Sometimes theres abrasion in that rubber hose and the wires are contacting or crimped completely. Use ISTA "status of contacts" or something similar. I cant remember, use live-readout.
5. Check fuses.

this should help you get to the bottom of it.

Click to expand...

Thanks man
the footwell module is placed in a place where it can get wet from car shampooing, and the connectors can be corroded, but also water can get into the wiring.
what are you using for diagnostics?

1. A second hand module must be matched and coded to your car. you need ISTA for this. you might also need to re-fresh your cars i-level or i-step, older firmware can misinterpret signals.
2. Electrical load from headlights changes the system voltage and can expose weak grounds or alternator fluctuation in current supply. A weak ground is a very obvious thing if the footwell module is cooked. Ground connections get corroded and you get a shit ground connection. clean all grounds in the footwell properly and spray with electrical contact cleaner then torque down properly. I have seen grounds tightened so hard, that the wires crimped out and had weak contacts. The nut looked like Thor tightened it, but the wires were loose
3. Check for >0.3 V across the battery at idle with lights on; if higher, I suspect alternator diodes will need to be checked, less commonly happening, but still possible. 9 out of 10 times its weak contacts to ground.
4. Finally check the door latch microswitch/latch. Sometimes theres abrasion in that rubber hose and the wires are contacting or crimped completely. Use ISTA "status of contacts" or something similar. I cant remember, use live-readout.
5. Check fuses.

this should help you get to the bottom of it.

Click to expand...