W203 wont start lots of lights on!

[DavidIR]

Hi,
my daughter's c230 1.8 Kompressor wont start ... engine not turning over.

recent history ... engine management light on due to failed o2 sensor (upper) caused by oil leaks on both cam sensors then getting into wiring loom. So I replaced both cam sensors also fitting an intermediate connector as preventative, then replaced both o2 sensors and gave connectors a thorough clean with electrical contact cleaner. There was evidence of some oil having leaked into rear connector of ECU which I have cleaned our three or four times over last two weeks. all above undertaken two or three weeks ago. all running well and having cleared engine management light didn't come back on.

on friday whilst I had car i decided to also change automatic transmission oil and filter. also gave the ECU connector another clean as still some faint traces of oil. After started first time and I drove about 8 miles with all well and no lights on.

Saturday morning when turned ignition lots of lights on ... yellow ESP, red brake, red SRS, yellow engine management, and low fuel light on (despite half a tank with gauge acknowledging that). On turning ignition engine doesn't turn over. The battery is less than two months old. Lots of other electric working fine including all lights, windows, air con etc., radio.

Help ! has ECU failed?

david

 

[AltonAnt]

Could be as simple as low battery voltage. Have you checked it?

 

[markjay]

Is this the M111 engine (2.0L, up to 2003), or the M271 (1.8L/1.6L, 2003-2013)?

The first thing to check on the M271 engine is that the timing gear hasn't failed... if it did, it can be fatal for the engine.

On the plus side, a 'Christmas tree dashboard is usually the sign of low voltage, as AltonAnt said, so check the battery voltage first, even if the battery is new.

 

[DavidIR]

Well, since the battery is virtually brand new and everything else including headlights work I have assumed it won't be the battery. I havn't got any equipment to check it but I could attach jump leads from my wife's car to see if that gets it to work!

I'll give it a go!

 

[markjay]

As for the ECU... you say you have replaced the leaking camshaft position sensors and fitted the extension wire, but you are correct in thinking that the oil may have travelled up the wiring loom and into the ECU.

If you don't want to spend money on the ECU without being certain it's defective, you may need to get someone with STAR to carry out proper diagnostics.

Alternatively you can just remove it and send it to a firm that repairs ECUs. If the existing ECU can be repaired, there will be no need for coding to the car, which you'll need to do if replacing the ECU (again, STAR required for coding).

 

[markjay]

Well, since the battery is virtually brand new and everything else including headlights work I have assumed it won't be the battery. I havn't got any equipment to check it but I could attach jump leads from my wife's car to see if that gets it to work!

I'll give it a go!

There should be a 'secret menu' in the Instrument cluster that shows battery voltage, alternatively you can get a cheap multi-tester from Amazon/Argos/eBay/Halfords etc for under a tenner.

 

[markjay]

....or something like this:

Jazooli Digital 12V/24V LED Car Cigarette Socket Voltmeter Voltage Battery Tester: Amazon.co.uk: Automotive

Jazooli Digital 12V/24V LED Car Cigarette Socket Voltmeter Voltage Battery Tester: Amazon.co.uk: Automotive

www.amazon.co.uk

 

[markjay]

BBA-Reman used to be the go-to for ECU repairs, though Googling it it seems they may no longer be trading? That's their website, anyway: Home (GB) | BBA Reman

 

[DavidIR]

ok, I have just connected jump leads and tried a jump start but made absolutely no difference.

Timing ... isn't it a chain rather than a belt? In any event I drove 8 miles absolutely fine and into my yard and parked with no apparent engine issues until next morning all the lights and no turnover. Surely if timing would turn over but not start ?

david

 

[markjay]

I agree, this sounds more like an ECU failure than timing chain failure. But on the M271, timing gear failure is the number one cause of engine failure, and in the majority of cases it's fatal, i.e. new engine needed. It's a chain, but the teeth on camshaft sprocket wheels wear prematurely, causing chain slip and eventually the pistons hit the valves resulting in damaged pistons and bent valves.

But as you pointed-out, the engine would turn but not start.

Might still be a good idea to remove the cam cover when you get a minute, perhaps the next time you carry-out a service, and inspect the timing gear... the photo below shows the worn teeth of a sprocket wheel from a failed engine (on the left) compared to the teeth on a new sprocket wheel.

But obviously you need to get the car fixed first...

 

[DavidIR]

Thank you both for your replies. I'll buy a multi tester today so i can check voltage and if that's not the problem I'll remove the ECU and send it off for testing.

Part of my difficulties are living fairly remote in rural cumbria! nearest car parts shop or Halfords is 17 miles each way! Same issue to get diagnostics on the vehicle when its not running!

cheers
david