ECM-26B0 Injector Power Signal too high
 

Guys - I need some help in fault finding this problem on cyl 5.

The previous owner had a misfire ( 2006 XC70 D5 185 ). The dealer spent some time investigating; cleaned the injector, checked connections, finally thought the ECM was faulty. The PO got an ECM cloned and fitted and it made no difference.

I have changed the injector itself and done a leakback test which is OK, so is fuel correction. No other codes in VIDA and it passed the MOT emissions with no problem. The misfire seems to be there only when cold, seems fine when hot.
There IS a problem with the DPF clogging but that may be caused by this problem, not the other way around?

The swirl mechanism was broken so I have replaced that and cleaned the EGR.

VIDA only says possible source is 'Internal fault in ECM' but as I say the clone is the same.

Where do I go next?

Cheers
Joe

you need to fit a new Loom connector to the injector , You have started at the wrong end of the chain ...
first item should have been connector , second the injector and third ECU ( ECU is always very last on the list )

Two of these 30765319
you will need a very thin tool/screwdriver to release the terminals from the housing .

Great, thanks, Clan.
What is the logic to a 'Signal too high' message being caused by a dodgy connector, which I normally associate with low voltage being passed.
Is the ECM having to pump out more electrons to overcome high resistance?

Cheers
Joe

signal too high means the injector is showing high resistance to the ECU so less load therefore higher signal voltage than if the injector was getting it's full quota of power . You might be able to reproduce the fault by wiggling the connector . A lot of vibration there on a diesel .

I had similar misfire / poor running issues on my 2007 185 D5 xc90 recently, also related to cylinder 5. See this thread: http://www.volvoforums.org.uk/showthread.php?t=266079
I had already tried to check wire & terminal resistances and all appeared fine, it only showed up as a fault on mine after everything was thoroughly warmed up.
Totally resolved now after replacing the terminals with part number 30765321, listed as a 'repair terminal' and which contains 2 terminals pre-crimped to lengths of wire. About £8.40 from the dealer.
I used a safety pin to release the old terminals from the plug.
Could be that cylinder 5 is a bit susceptible as the loom is tight in this area - I left some extra length on it when I soldered in the repair terminals.

Unfortunately the replacement connector made no difference, Clan.
So it now has :
Replacement injector
Replacement connector
Cloned ECU (by PO)

With no change, so the next logical thing to check is the wiring from ECU to injector.

Can anyone point me at wiring diagrams and pin outs in Vida? Must be in there somewhere but I can't see them.

Thanks
Joe

While not disagreeing that wiring is a likely issue, could it be a burnt valve seat ? Back in the day on more agricultural petrol engines, I would check by listening to an open carb when cranking over - or you could do a compression test.

I don't *think* that would give this specific code. In fact my original 'old school' thinking was the same as yours and my first step was to do a compression test, but I struggled to find a tester with a small enough adapter for the 185 (which I think is a lot smaller than the 163?). Then I got diverted by Vida being able to do a pseudo-compression test, which showed no problem.
There may still be a mechanical fault when I get rid of the electrical ones....
Cheers
Joe

Spend a few minutes looking at how difficult it will be to get into the loom and when I removed the tape around the very first junction and pulled the wires out this is what I found.....hopefully an easier fix than I expected !

I realise this is an old thread but just wanted to check if this was ever resolved? I'm getting error code ECM-2670 on a 2011 XC90 D5 (Injector power stage, cyl 1 - Signal too high). After an initial attempt to clean the old terminals I've replaced them (in injector 1). This has not resolved the issue but it is now intermittent.

I would like to completely rule out wiring before going down the injector replacement route.

(Long-winded background story below)
I've been trying to diagnose a slightly rough idle (causing intermittent steering wheel vibrations strong enough to make the keys jingle at times) After the first attempt to clean the old terminals it ran smoothly for a few glorious minutes and acceleration and power delivery was smoother...then whatever the problem is returned and it went rough again. After replacing the terminals it's now random, on my 40min commute I'll feel it change several times and the error code will come back (I have an ebay VIDA/Dice rig and clear the error code each time).

One other point of note is after spending a fair amount of time trouble-shooting this issue and not seeing any error codes at all in VIDA I bit the bullet and took it to a local Indie Volvo specialist and paid for a full CAN software update. It was only after the software update that this error code appeared. The mechanic took the car for a test drive but typically it was behaving itself and he said it felt and drove like a normal XC90.

It's run like this since I bought it 2 months ago and I would have believed him if I hadn't had the brief glimpses of what it should REALLY feel like. I've split the injector wiring loom about one third of the way along when I changed the terminals for injector one, the inner wire casing are slightly browned from the heat but no obvious damage. Any help appreciated :-)