Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - tcpaulh

Volvo S40 SE
RE05 XAH
1.8 Petrol
Engine designation according to manual B4184S11
Vin YV1MS214252102870


Bought car a couple of years ago and started getting "reduced engine performance" on dash readout. Garage determined throttle position sensor faulty and replaced pedal+sensor

Car uses 1/2 a litre of oil per tank of petrol. Drives well 35mpg.

Last week I was on a 200 mile run and stopped off for a break. Reduced engine performance dash warning had been showing for months but I couldnt afford to have it looked at or was ignoring the problem...
Car refused to start. No life from engine and a bunch of dash warnings:

Power steering service required, park assist service required, reduced engine performance, immobilizer see manual, brake failure stop safely


Recovery service called out who couldnt start it at first but then after a failed bump start (no engine activity) the car came to rest and after that it started as normal.

Took to garage and they found:

Error Codes
2138 - accelerator pedal position sensor faulty signal
2121 accelerator pedal faulty circuit *
D900 Configuration fault. Software faulty
C168 Intermittent fault. Commmunication brake control module (BCM) signal too low
C400 Control modulle communication ; faulty signal
C167 Intermittent fault. Communication central electronic module (CEM) signal too low.

*Cleared all codes and 2121 returned. Pedal+position sensor replaced (for the second time)

Paid for work. Started car and "reduced engine performance" on dash. Turned off engine, spoke to mechanic as still at garage. He turned ignition on and error no longer displayed so drove home keeping fingers crossed.

Car parked up for 3 days then today I went to start it and got a bunch of errors on dash readout. Same as before. No life from engine. Lights come on etc as normal.

Questions

Whats wrong?

Have I got any reasonable comeback with the garage?

Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - elekie&a/c doctor

This car is basically a Ford Focus in drag. Any basic checks carried out? Battery ,charging system? I like the comment"Reduced engine performance dash warning had been showing for months but I couldnt afford to have it looked at or was ignoring the problem..." It,s an old car,they go wrong.The garage have probably tried to get you out of trouble as best they can..It is possible you have made matters worse by ignoring the problem.

Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - Metropolis.
‘ford focus in drag’ ‘...possible you have made matters worse..’

Not your usual helpful self there doc...
Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - hardway

Check out the charging system.

And by that I don't mean getting a mechanic to stick a mulimeter on the battery.

A full system check from load testing the battery on to full charging system check.

Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - S40 Man

I had the alternator go on my 04 s40. The main symptom was intermittent lack of power. Steering. It's electrical not hydraulic. You'll know if that happens, it's quite alarming!

Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - S40 Man

I used to have a 2.0 d see s40 and head loads and loads of similar electrical gremlins. I eventually bought a ppc diagnostic code reader which was excellent. It's a Volvo specific one. Mine certainly paid for itself. One thing the AA did was disconnect the battery then put a screw driver in the hole at the end and put the positive least on the negative terminal. This apparently clears the system. The other trick is to click the key fob lock/unlock 10 times in rapid succession.

Try either of these next time immobilizer cut in.

Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - Big John

New battery required?

Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - Gibbo_Wirral

I'd agree with that. Its autumn, its colder, demand on the battery is higher. If its anything like a Peugeot, if the battery is anything less than 11v you get all sorts of erroneous error messages.

Volvo S40 SE 1.8 Petrol 2005 - Car immobilised. Root cause of error codes? - daveyjp

Another vote for the basics first - battery and charging circuit.

I find it incredible that systems are built to give hundreds of diagnostic codes, however a simple warning on start up that battery voltage is low doesn't feature.

Many cars have diagnostic readouts for such things, but you need to know the combination of button presses to get to them.

As the Volvo is based on a Ford it may be possible to access this info - I could do so on my X type.