ECM-26B0 Injector Power Signal too high

[seanc]

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.

[Joe H]

Originally Posted by seanc

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

[guido]

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.

[Devonsteve]

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.

[KBB]

Originally Posted by guido

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'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.

[Dude]

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

[5cilinder]

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?

[Dude]

Originally Posted by 5cilinder

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

[5cilinder]

Originally Posted by Dude

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).



Thanks again

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

[Dude]

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.