Airbag and ABS light on

[Arkis]

Hello,
over the year I have been doing big service on the car. It started on 5/2023. It should have been a simple timing/belts job but then I noticed that when stepping on a gas pedal the coolant is going up. There were gasses coming to the coolant (no oil mixing yet). So I did the headgasket job including full top end gasket set and all fluids.
When I connected the car to the battery and started the car the ABS and Airbag light was on. It wasn't ON before the job.
The lights are ON all the time. When I turn the key they lit up and don't turn off until I turn off the engine. No codes on the diag.

There is also a check engine light (code P0135). I think that it's on because the fuel is over a year old now. The O2 sensor reads 0,2-0,4V so it should be good.

I tried

• checking all connectors if I missed something when assembling the car back

• BSI restart

• checking the grounds from the battery, all looks like new and are cleaned, there is continuity

• All fuses (including MAXI fuses in the engine bay) are good.

• The connectors under the seats are good.

• The ECU's connectors are good. Inside of the ECU is clean. No sign of corrosion.

All the connectors I unplugged are cleaned and sprayed with a contact-cleaner.

There is an unrelated electrical problem with the car. The thermometer shows no data on the dash, but via diagnostic tool I can see the temperatures are good. There is only one temp sensor on my car. When the car reaches 90°C, thermostat opens and a fan kicks in, it starts blinking STOP on the dash with parking brake symbol lit on. The car does not overheat and it turns off after a while. Then is cycles like every 20 minutes.
I think it is not related to my current problem with ABS and Airbag light but I mention it anyways because it might me some dying module.

[RichardW]

What diag tool are you using? If the lights are on there should be some codes - unless the ECUs are off line (which a decent diag tool would show).

[Arkis]

Just general OBD scanner on ELM protocol.

I bought Lexia clone, but have no luck getting it to work. Tried like milions version, systems and installers but it does not connect to any of our cars. It all seems to be working but it does not connect to ECUs (no response from ECU).

I will try some local group, if somebody has a Diagbox.

[Paul-R]

Is the Diagbox clone that you bought a full chip type? How much did you pay for it? What versions of Diagbox have you used? For our 2013, C5 version 7.58 is sufficient.

[Arkis]

Yes, it's fullchip. It was around 90€ back in 2022. I see it is still active, but much higher price today.
https://www.aliexpress.com/item/3296533 ... 1802JBV76K
I tried to use 7.56 (i think... it was the basic system back in then) 7.76, 7.82, 9.68 which are recommended in the description. The VCI firmware was updating with each version. Tried both clean installing right into Win Xp systems on a notebook and even trying to use pre-installed Virtual Machine. Back then I thought I was just stupid and couldn't make it work.

But last week I saw there is easy install from PSA-DIAG forum and gave it a shot again. It is using 9.18 version with update to 9.186. Both with 4.4.0 firmware version.

Still same result. Back in 2022 and this year. Notebook recognizes the diagnostic tool, there is lit green LED on the diagnostic tool. But the diagnostic tool does not recognize connected car. Auto detection not working. When I input all data manually it let's me into PP2000/Lexia (depending on what car I choose) but when I try to do scan, it says "ECU no response" on all modules. It does this on both of our cars.

[Arkis]

I just noticed one thing. I was playing with Diagbox again and noticed clicking from the front of the car when hood was open.

When the ignition is on (without starting the engine) the ABS module (ECU/pump) is clicking nonstop. It sounds like a small relay. Is it normal?

[Arkis]

Solved. Problems were unrelated.

Airbag solution: There was a broken pin in the connector from electric harness to the steering wheel levers. soldered new pin on it and no more airbag error.

ABS light was my fault. Nothing wrong at all. When I was working on the car it was on jackstands with all 4 wheels up. I was turning the wheels one by one when checking the wheel bearings. Even with engine on because I was chaning trans oil (which must be hot). So the car was getting signals only from one/two wheels at a time and thought the rest of the sensors are faulty... Got a new Lexia tool which read the codes and all 4 sensors had codes stored. Deleted them a voala, no ABS light even after 100 kms.

Code P0135 was because of faulty lambda sensor. It was doing readings but the heater element was not working (tried to measure resistance on the pins and it was unmeasurable). New sensor (went with Delphi) solved the problem.