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 :-)

I think if you look at where Joe started and got to, he ended up replacing and splicing the new connectors on and had the same problem. Then pulled the loom cover off until he got further down and found those damaged wires. Wouldn't hurt for you to do the same in case it might be that simple.

Yes, in my case the wiring damage was obvious once the covering was stripped off. It is easy enough to remove all along it's length to the ECU so worth doing that. (getting it covered up neatly again is more difficult :-) )
In my case that almost solved the problem, the last part was getting the replacement (used) injector coded by Volvo.

Hope you get it sorted, it is very frustrating with an intermittent problem like yours.

Joe

Thanks for the reply. I've since removed the connector block from the ECU and cleaned the contacts with contact cleaner spray. While I was there I measured the resistance between the ECU connector block pins the injector plug pins and both read 0.15ohms which was the same reading as the plug on injector 2 so I assume that's normal? I did find a point where the main harness had been rubbing against the edge of the engine block, no wires are broken but one or two look a bit stretched so I'll investigate that further and as you suggested I'll check the whole length of the wiring harness.

At the moment it seemd to be pointing towards the injector though. I added some injector cleaner to the last tank of fuel (I know this isn't recommended and most of them are snake oil but I thought it was worth a try) and it may be coincidence but the issue seems to be a bit less frequent and the DTC code isn't being generated as often. On yesterday's commute I gave it a good revving once it had warmed up and after that it behaved itself for the rest of the journey. I'm inclined to leave it for a bit to see if it sorts itself out, if not I'll replace the injector.

Did having the injector coded make any noticeable difference? I was quoted about £130 from a local dealer just to do the coding, I've read other posts where people have just swapped them over with no apparent issues.

I had something similar on my bmw 3 series 3.0 diesel a few years back. I used bmws software on my laptop to diagnose a misfire. Initially it said injector 5 not firing properly. So my first thought was faulty injector. I used the software more and dug deeper and got more info. The final message was resistance too high. When I checked the injection harness, the wires were all completely stiff. A new loom was only £45 so replaced it and it cured the problem and ran better than ever.

I'm afraid that your resistance test proves only one thing and that it has not got an open circuit. Injector circuits five with 120v at around 20 amps. If your harness was held together by only one single strand it would show a very low and acceptable resistance reading but could that one remaining strand handle 120v at 20 amps?

Best test on injector circuits is with an oscilloscope measuring voltage at the ECU and at the injector connector, that will show any loaded circuit dynamic voltage drop along with inductive current clamp to establish the amps flowing as low amps means circuit resistance if supply voltage is correct.

Codes 26B0 etc
 

Just found this old thread and wonder if anyone can advise?

I'm getting occasional injector codes 2670, 2680 and 26B0 which are injectors 1, 2, 5.

This thread says that's "injector signal too high", however my local Indy garage found a 26B0 reading and report it as "insufficient fuel pressure" (not a VIDA, but better than my basic code reader. I believe VIDA will identify which error when there are more options for a single overall code?)

I've taken a first look at the injector wiring without as yet dismantling much, however, there is clear damage to some wiring (car is an XC70, D5 185, 2006, 144k miles). There's a wire that routes around the offside side of the oil filler cap and its conduit is badly cracked and broken, though the wires look ok for now (I have done a temporary fix). There are also some other injector feed wires I can see where they break out from the loom that have lost their covering. This all suggests that at the age and mileage I would do well to properly check all the injector wiring.

So, questions: (I've never done much on this engine myself, and diesels are a bit of a mystery to me, however, I am reasonably competent, at least to know when to give up and get someone qualified to do it)

1. Which is cylinder 1 - nearside or offside? This seems to be so obvious that nowhere on the net or the Haynes manual does it say. AFAICT, no.1 is offside, left as you look at it standing in front of the car

2. Am I right that to get at the injector wiring (mostly behind the engine?) the sequence is: disconnect battery, remove engine top cover, remove transverse strut (both ends and a connection to the cyl head, then remove the plastic cover above the injectors (into which the top cover hinges) with two nuts either end at the front and twomdown the back of it)?

3. And finally, could water in the fuel cause these codes? The local filling station we use has been out of action, many cars locally reported by our Indy garage with water in the fuel, including my wife's XC60 D5. I have had the fuel filter changed, codes cleared and will see if they come back. My feeling is it's not this, but dodgy wiring.

Thx in advance

1 if you stand in front of the car left is 1 and right is 5

2 correct

3 this is electricly related ...injectorcoil, wiring or the amplifier in the ecm
Most suspect is the wiring.
I also suspect that bad earthing will cause or worsen this
How is the car starting under different temperatures? good idling?

1., 2., thanks

3. Starts fine, regardless of hot or cold. Idles ok. You'd basically never know from its running that there are any codes up. I do get the very occasional momentary loss of power, a bit like an unsmooth gear change on the auto, but I think it's perhaps a very short misfire. This I could easily put down to a slug of water coming through, hence fuel filter change and a wait and see, though the garage didn't find any collected in the filter (unlike my wife's car, which had lots).

Will check the earthing, but what I can see has no corrosion/crystallisation at all.

I recently had a Bosch service centre check the vehicle when it wasn't running right, they found nothing, having checked all the wiring end to end and thought it could be the ECU. Those codes mostly went away when I asked for the Air Mass Meter to be changed, but left these injector codes, so I suspect the AMFM and these injector codes are different issues. At present, clearly intermittent, the hardest type to find.

Thanks again

Those injector codes will/can be responsible for misfires (vida counts them)

Thanks. As I want to keep the car, thinking of getting it to an Indy Volvo garage to give it a good going over, it's a 100 mile drive but he has a good reputation.

I think I know where you are going.

This is likely to be caused by poor injector plug terminals, they move slightly with engine vibrations and eventually the grip reduces, volvo do repair wiring terminals with 6 inches of wire pre crimped to the new modified terminal. It is certainly the first thing to do , and make sure the wiring to the injectors is tied down so they are unable to move with the engine vibration.

PN/ 30765321 x 8

I guess i will also ask in this old thread.

2006 xc70 with D5 185hp here.

Same issue for me, i keep getting Injector 5 signal too high. First time it happened i was driving, but now its happening on every cold start.
What confuses me is that if i use vida and clear the code, the car is running normal until next cold start. When its running while the fault is present, its running really rough, like it has air in the system.
Vida also gives me a code with low fuel pressure that seems to come at the same time as injector 5.

I have not changed the terminal yet, since i first now read about that, but i have looked at the loom around 8 inches in, i found some cracked wires that i changed out but it didnt help.

Is the repair terminal my first step as well? i think i should look more into the loom while waiting for the terminals, where do the injector wires go, to the ecu?

Thanks in advance for help and advice

also consider the fuel pressure regulator.

Hi again

I need some help.

I have changed the terminals on injector 5, also went thru the entire loom.
Fuel correction looks good, i ohmed all the injectors they all came out at 0.6ohms.

I found a fault on the sensor or regulator or whatever it is on the right side of the fuelrail, it actually was leaking internaly. Changed this, car still had a long cranktime.

Changed the terminals on the injectors yesterday, car started right up with no errors, ran smooth. Today it also started up fast and ran smooth, but still triggered low fuel pressure, signal too high and injector 5 signal too high.

I noticed that the fuel pressure was like 480000 hpa while nominal value was like 360000 hpa, is this a clue?

after i cleared the codes, fuel pressure went down to about same as nominal value.

Im starting to think its fuelpressure triggering the injector fault, but maybe thats a mistake?

could it be the fuel pressure sensor since its allowing too high pressure when cold? thats the left on on the rail isnt it? or could it be the regulator near the hp pump? or any other suggestions?

The current to the fuel pressure regulator i also wonder what should be, mine reports around 400-500ma.

A pain to troubleshoot this since it only happen once a day or every other day.

Im attaching a couple of screenshots, note that of the fuel pressure i took after clearing the codes.

I have also asked for help on another forum, at this point i need all the help i can get.