Random stalls and now no start on my V70 '98 10v

[OffsetBuffalo]

Hello everybody, I just joined the forum and need help with my parents V70 '98 10v (engine code B5252FS, Fenix 5.2 engine management).

They have had the car since I was a child and for more than 15 years it never left us stranded.
Until last weekend, after when my dad filled up the gas tank, it wouldn't start anymore. At least: it starts but immediately shuts off again. After 20 minutes, the car did start but was only managed to run for a few hundred meters before stalling again. Roadside assistance said the fuel pump was broken, they towed the V70 to a mechanic.

The mechanic refurbished the old pump and the car drove again. However the next day, after driving more than 20 kilometers, the same problems arose again. Back at the mechanic, he replaced the fuel filter (the old one was only a few months old), test drove the car for > 10 km and said it was fine.

Today however, the same problems still exists. I was getting tired of it so I visited my parents and did some diagnosis. During the car-starting-and-immediately-stalling condition, the pump does switch on when the key is turned, and turns off after around 3 seconds. So the relay is probable fine (I've read lot of people have problems with this relay). I made an LED flasher to read fault codes from the Siemens Fenix 5.2 ECM. The LED flashes: 1-1-1 so no DTC stored. I confirmed the LED flasher actually works by unplugging a sensor, which did indeed generate a flash code.

The next day, I wanted to go for a test drive, but the car now doesn't start at all. Or at least, it starts fine, but then stalls immediately as soon as it runs (just like before). Seemed like an immobilizer issue to me, so I tried another key: same problem. I decided to hookup Vol-FCR to readout codes from the other modules:
- Immobilizer: 321 Initiating Signal Absent from ECM
- ABS: 432 Control Module General Interference fault
- ECC: 414 Fan motor pass comp temp sensor, faulty signal & 135 Engine coolant temperature (ECT) signal missing

The ABS and ECC modules DTCs might not be relevant, but I included them anyway (note that the A/C on this car is broken for years and the ABS did some funky things too in the past, altough I don't know if the modules gave these codes before).

What should you guys next advise on trying? Can the random stalls be explained by an immobilizer fault? Or does the immobilizer fault only explain the immediate stall after starting? Would the stalling be a fuel problem? Of more electrically oriented?

The car has had fine maintenance, recently the spark plugs and their cables were renewed.

Hope to hear from you guys! Best regards,
Feike from the Netherlands

[scot850]

Being a 98 European spec car, does your car have a chipped key and an antenna reader by the ignition key?

They key is larger than the non-chipped key and thicker.

Does the car have a spare ignition key? If so have you tried that as well? Try, locking and unlocking the car door with the key 3 or 4 times to try to reset the immobilizer. I doubt it will make a difference but worth a try.

I am not convinced it is an immobilizer issue as it runs for a while.

The ECC will make the car harder to start, but usually won't cut the engine. However it may cause the car to over heat.

Check the connector for the ECT. It should be mounted behind the power steering pump. The connector is known to fall apart and the wires corrode. There are details on how to test the ECT by checking resistance values against ambient temperature.

Have you tried replacing the fuel pump relay? Worst case you could try using a jumper wire to see if the car runs for longer or starts better. Do not leave it in long term, it is just a way for getting the car going. There are ways of repairing the pump relay if it is faulty, but if it proves to be bad, it may just be best to try getting one from a junk car to test or replace it. Otherwise we would only recommend an OE Volvo new unit.

Neil.

[OffsetBuffalo]

Thought I might post an update on how the car's doing. The problem isn't entirely fixed, but the car drives again.

We tried replacing the fuel pump relay, that didn't work. Then we tried bypassing the relay. We did this with a jumper wire (with fuse in between). The car now starts and runs fine; the fuel pump just runs when the ignition is on.

After driving a little with without any issues, I noticed the RPM signal dropping for a very short amount of time. It lookes like the gauge would loose signal for a sudden, causing the needle to drop, but then immediately getting signal again, causing the needle to jump to the true RPM value again. The needle only drops a few millimeters but it happens one time per 20 seconds, although sometimes more often.

I had a look in the repair manual and apparently the fuel pump is shutoff then the ECU looses it's RPM signal. So I thought: replacing the RPM sensor would do it. The manual said this sensor was the crankshaft sensor; this appeared to never have been replaced. Replaced it with a new sensor but the issue is exactly the same.

Since we have driven the car for more than a month and few hundred km without issues. But I still want to fix it good.

So you guys have any idea what to try next? Some way to check the cabling maybe? Thanks!!!

[bronco]

your user name is my router password

[OffsetBuffalo]

your user name is my router password

Haha that's quite funny. Microsoft once gave me this username lol

[misha]

You have 2 problems:
1.immo fault dtc 321
2.Ecc fault dtc 135 (ect sensor)

Reset codes and see which ones comes back.

Re-seat engine ecu few times and check fuses for immobiliser...there are few of them,not just one.

Check connector for immo box,re-seat it few times.It's deep under the dash on a plastic carrier bolted onto steering assembly.

It does not send a "OK" signal to engine ecu.

Check wiring for ECT since they are prone to corrosion and failure.