2000 S70 2.4 Erratic Injector Pulse Topic is solved

[fastcars1173]

Pulling the harness apart is about the only thing that I haven't done. On this model the wiring goes straight from the ECU to the injector so if it was a short it would be a bad wire or wires as it's doing it on 4 out of 5 cylinders. #1 is the only one that is steady. I'll pull it apart and check the wiring and ground source wiring.

[abscate]

I think double bug can do it over the Internet but cloned VIDA won't work for marrying components.

For OP, I would like at the fuel pressure regulation and/or coils as potential trouble spots

[shaker_chi]

I had an ECU crap out on my 1994 850 n/a at about 180,000 miles. I was lucky enough to pick one up for $50 on ebay and plug it in.

[fastcars1173]

Problem solved. It was the ECU.

[precopster]

Is this a turbo or non turbo?

With Dice on a Windows laptop and Doublebug's help you can swap the ECM with one from a dismantler however ONLY if it's a Bosch system from a turbo.

How did you handle the immobiliser in the ECM?

[lockwoodfe]

I am having similar problems. #2 and #3 injectors shut-off. After ruling out everything but the ECU, I eventually came to find out my ETM had a blown fuse. Replaced the fuse and the car started running normally again. Apparently these Volvo's go into some kind of safe mode where they shut cylinders down for certain fault codes. My car would not run over 1500rpm when in D either but I could rev it in P or M. Kind of annoying since it sent me on a wild good chase since it was initially obvious that I was missing some cylinders. In my research, I found that the 1999-2001 Volvo's had frequent problems with the ETM and in fact there was a recall, although it is expired now. Also read the ETM is keyed to the ECU so you can't just swap it out. The most common ETM problem is that there is a mechanical wiper for throttle valve position that wears out. There are some after market kits you can buy to replace with a non-contact wiper. Requires some disassembly and soldering.

[precopster]

lockwoodfe: "Also read the ETM is keyed to the ECU so you can't just swap it out"

You should check your sources. ETMs can be swapped out if they contain a compatible software version to the ECM Engine Control Module (some people call it the ECU however every board has an ECU so this is a very vague description)

I've been swapping ETMs for 5 years on various vehicles by checking the system software with Vida. Once you establish which version is fitted to the ETM you can determine if it's compatible with your car. Also they can be programmed to match of course.

Great find on what exactly is "limp mode" that is certainly interesting that it cuts injector pulse to 2 cylinders though in practise you can't overcome it of course. Getting the latest firmware installed on your car is the best way to ensure you don't get limp mode as later software is more tolerant of small variances in throttle angle. In fact later software (post 2006) won't place the car in limp mode even if one of the sensors goes totally offline.

As far as your blown fuse goes it will happen again. The armature is rubbing on the magnet occasionally and will short out every so often. It can be fixed with a total dismantle of the ETM so the magnet can be removed and re-shaped.