Partner 2008 B9 1.6hdi ABS, ESP, Braking system fault

[buahahaha]

Hello, I have a problem with my car. About a month ago, the ABS, ESP, ASR lights came on along with a “braking system fault” message. The speedometer and mileage stopped working, and the steering became heavier.

When I got home, I checked all the fuses, the ABS module connector, and the rear ABS sensor connectors. Everything looked clean with no visible corrosion. After starting the car again, the errors disappeared, and I was able to drive for almost two weeks without any issues.

Then the problem came back. I connected a diagnostic tool and got the following error codes: 0150, C1408, U1113, U0122, P0500, U0121, 04C3, 05FF, 001C.

I decided to replace the rear ABS sensor since it looked suspicious. I also cleaned the ABS rings. After driving about 10 km, the errors didn’t disappear on their own. I came back, turned off the car, started it again — and the errors were gone. They didn’t appear for two days, but then came back again.

The errors always appear only when turning the ignition on and starting the car. If they don’t appear at startup, I can drive even 500 km without any issues. But if they do appear, I can also drive 500 km and they won’t go away while driving — they only sometimes disappear after turning the car off and starting it again.

All other electronics in the car work perfectly.

Any ideas what could be causing this?

[RichardW]

What year is it? This might be relevant: viewtopic.php?t=73133

[buahahaha]

thanks for reply, but my partner doesn’t have this speed sensor

[PaulC5]

Check the battery voltage before the first start of the day. If fully charged it should be about 12.7 volts but if below about 12.5 volts it needs charging.

I have not bothered looking up the meaning of the codes but if you can give their descriptions it will help others who may be able to provide advice.

[buahahaha]

0150- Vehicle Speed Information Fault. Resistance Too Low
0150- Vehicle Speed Information Fault. Resistance Too Low
C1408- Vehicle Speed Data Fault. No Signal
U1133- Vehicle Speed Data Fault. Vehicle Speed Information Missing
U0122- Multiplexing Absence Of Communication With The ESP
P0500- Vehicle Speed Signalmaximum Speed Exceeded
U0121- Multiplexing No Communication With The ABS
04C3- Brake Fluid Level Fault (Signal Not Coherent Or Level Too Low)

Regarding the battery, over the weekend, after the ABS sensor replacement, when the faults had temporarily disappeared for a couple of days, I put the car in the garage and connected the battery to charge (this was advice from the person who did the diagnostics). It was charging for 6 hours. After I finished charging and reconnected the terminals, the moment I turned on the ignition the faults came back on, even though before charging they were not showing.

[Paul-R]

Did you follow the BSI reset procedure when reconnecting the battery?

[buahahaha]

I think not. Are you talking about this one ?

1.Put the driver's window down, lift the bonnet and ensure all equipment is switched off.
2.Ensure all doors are closed and remove key from the ignition.
3.Wait for 3 minutes, disconnect the vehicle battery and wait 15 seconds.
4.Reconnect the vehicle battery, wait a further 10 seconds (do not open doors.).
5.Switch on the side lights through the driver's window.
6.Switch on the ignition and check system's functionality.
7.Hold lock button on key down for 10 seconds.
8.Remove key open & close door test central locking system.
9.Start the engine and complete the system's check.

[Paul-R]

Yes

[myglaren]

I would say that step 3 is insufficient. The various capacitors need time to discharge at this point and generally 15 minutes is more appropriate, or to short the + and - leads through a resistor, a festoon bulb being a suitable one.

I no longer have a Citroen and that sequence is not needed but my daughter has a C3 that does.

[buahahaha]

Today, after the night, I got into the car and drove about 15 km without any errors. But for the first time while driving, warning lights came on, and the speedometer and odometer started acting weird – sometimes showing, sometimes not. I’ll share the YouTube link. I haven’t done the BSI reset yet. I’ll do the BSI reset in the evening.

[buahahaha]

Today I was driving all day and errors kept appearing for a second while driving. Then, when the errors disappeared, I went to get a diagnostic check. When they connected it, it only allowed access to the ABS and BSI modules, and there was a new error.
P0562 – ECU supply undervoltage fault (not characterised)
All the other errors had cleared at that moment. So basically, either the battery needs to be replaced or there is a bad electrical connection somewhere.