ML320 CDI - fault codes and glow plug lamp

ML320 CDI - fault codes and glow plug lamp

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8bit

Original Poster:

4,867 posts

155 months

Wednesday 18th July 2018
quotequote all
Our 2008 ML320 CDI Sport has started keeping the glow plug lamp lit up for a minute or so after engine startup, even after waiting for the plug to go out initially. I scanned the car for fault codes, hoping to see something telling me that one of the plugs was on the way out but only saw two other codes which are:

P2133 - Throttle/Pedal Position Sensor/Switch F Circuit High Input
P2616 - Camshaft Position Signal Output Circuit High

Not sure if these things are connected to the glow plug lamp at all, I saw the latter code last year and the advice I found online was to change that camshaft position sensor, I did that and the code didn't reappear for ages, I stopped checking for codes so regularly after a while though so I can't say if the timing of those does coincide with the glow plug lamp appearing.

Any suggestions?

Dunit

637 posts

205 months

Wednesday 18th July 2018
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Check the ohms reading on the Glow plugs and not unusual for the Beru controller to go down!
Both are available from Europarts
There is a Jeep video on YouTube which will show you how to check everything from the output plug of the controller.

Paddymcc

936 posts

191 months

Thursday 19th July 2018
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Had similar problem with same engine in my cls, however the glow.light would stay in longer and sometimes not go out.

In the end I replaced all 6 plugs with bosch for the sake of £40 and had the mechanic change the controller which was approx £100 when he was doing my suspension work.

8bit

Original Poster:

4,867 posts

155 months

Thursday 19th July 2018
quotequote all
Thanks chaps, useful info. I think I've found the video mentioned - https://www.youtube.com/watch?v=gdT2ChsbKAo

If there was a hardware issue with the plugs or the controller then should I not expect to see a specific code for those, as suggested in the video? One thing I forgot to mention is that the car does seem to have to crank a fairly long time to start from cold, even if we wait a good moment or so after the glow plug light goes out after switching the electrics on, but it's not every time.

Dunit

637 posts

205 months

Friday 20th July 2018
quotequote all
If the wire has fractured in the controller it does not always show a fault code,And if the engine is taking as long as you say this points to a definite fault in glow plug / Controller.
Your lucky the weather is so hot as it probably would not start in winter.

tobinen

9,227 posts

145 months

Friday 20th July 2018
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You'd be surprised with winter starting. These modern diesels barely need a heat at all unless you're really dipping into minus figures.

Ref the camshalf position sensor, when mine started to play up on the 210 it would take ages to crank/start. Eventually it went into limp-home mode when running.

Hope you sort it.

loggo

410 posts

112 months

Friday 20th July 2018
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Same engine in my merc. I had a glowplug gone and slow starting. Fine when the glowplug was replaced but no codes showing and light went off immediately.

8bit

Original Poster:

4,867 posts

155 months

Friday 20th July 2018
quotequote all
Again, thanks all.

The slow starting has been going on for a while, certainly since last winter. I put it down to us (my wife usually) not waiting until the glow plug light went out before starting the engine but it started doing it even if we wait a couple of minutes when the car is started first time that day. I had read that slow starting was a potential symptom of the failing camshaft position sensor so tried that since we saw the code for it anyway but the code went away for some time but the slow starts sometimes persisted.

The car has done 70k miles and is ten years old now - this is the first diesel we've had, are glow plugs normally an occasional service item, like spark plugs on a petrol, or is it just "change when one fails"?

gizlaroc

17,251 posts

224 months

Friday 20th July 2018
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If it is taking a while to crank it is your controller.

The 320cdi is one of the only modern diesels that 'really' needs glow plugs to get going.

Just buy a new controller and plug it in, only take a few minutes.

8bit

Original Poster:

4,867 posts

155 months

Friday 20th July 2018
quotequote all
OK thanks for that. Someone posted earlier that the plugs and controller were on Europarts, I can't find them there - EuroCARParts have the plugs but don't see the controller. Any other source for the controller besides a Mercedes main dealer?

gizlaroc

17,251 posts

224 months

Friday 20th July 2018
quotequote all
8bit said:
OK thanks for that. Someone posted earlier that the plugs and controller were on Europarts, I can't find them there - EuroCARParts have the plugs but don't see the controller. Any other source for the controller besides a Mercedes main dealer?
I'm sure I got mine from ECP, think it was around £105 after discount.


Search for Beru Glow Plug Relay on eBay.



8bit

Original Poster:

4,867 posts

155 months

Monday 23rd July 2018
quotequote all
Aha ok, so it's fairly generic/universal then? Not a Merc or M-class specific thing really?

So I checked the car again for fault codes at the weekend and the one about the camshaft position sensor (P2616) has vanished but I now see two codes related to the throttle pedal/position sensor, P2133 and P2137. The car had a good motorway run at the weekend and seems to have started better since then. I know from my own Jaguar that when codes start coming and going or other odd electrical sort of issues appear the usual suspect is a tired battery. Our Merc is almost ten years old now, we've had it for just over four and as far as I know it'll still be the original battery. Are these things also susceptible to battery-related gremlins?

GlenMH

5,212 posts

243 months

Monday 23rd July 2018
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My W210 2001 E320 has had the glow plug light fault for the last 5+ years. All 6 glow plugs are showing an error code.

My indy specialist said "they all do that, sir. If you have a snag starting it, then we'll take a look". Even at lower than -5C, I have had no problems with starting it.

phazed

21,844 posts

204 months

Tuesday 24th July 2018
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Checking my service history, my 140k 2007 ml320 is still on the original glow plugs.

It always starts within the first second if you wait for the glow light to extinguish but cranks for 3 seconds or so if you try and start it straight away.

Mine has just started to show an, SRS warning.

Any ideas?

8bit

Original Poster:

4,867 posts

155 months

Monday 26th November 2018
quotequote all
Finally got round to doing something about this, got hold of a glow plug module (made by Beru) and changed it out last night. The glow plug light still comes on just after engine startup. Checked codes, I have P2133, P2177 (relating to Throttle/Pedal Position Sensor issues) and P2616 "Camshaft Position Signal Output Circuit High", nothing that specifically mentions glow plugs. Cleared them at the time, will recheck later.

Any suggestion as to where to go from here?