Lamba light on V70R estate

I am having a problem with the Lamba light on my V70R estate, It occaisionally comes on and we have to disconnect the battery to put it out. We have taken it to the local Volvo garage twice now and they are very vague about the fault, they say that it could be either a thermostat or one of the ECU's??? When the light first comes on the engine cooling fan also comes on for a few minutes and the temp gauge reads zero if you stop the engine and then restart it. also the light seems to come on when we are driving down hill with foot off the accelerator. The engine temperature appears normal. Performance is not affected in any way.

I've found a better way of reseting the lambda on my V70 AWD (not R sadly)

In the main fuses, offside near windscreen in bonnet, the large red fuse nearest the windscreen is for the ECU.

Remove, leave out for 15secs and replace. Obviously with key out of ignition.

Saves radio code, clock and other faffing about.

Worked for me.

Happy Christmas

Keith

[cootuk]

If I was paying them money to read the codes. I'd want to know the actual readout that the computer gives.

[Chris_Rogers]

Knowing the year would help as the engine ECU changed in late '98.
I would guess that the coolant temp sensor or it's wiring is the problem. But the real way forward is to get the fault codes read and ask for the fault code no. and text.
Post back when you have this info.

hi i got a efi 422 code baro sensor signal error lights been reset.

any ideas ?

[Chris_Rogers]

I assume we are talking about a '98 with Motronic 4.4

The sensor is behind drivers side headlamp.

Try this:

Possible cause of code EFI-422

Signal too high
-short-circuit to supply voltage in the signal cable
-open-circuit in signal cable or ground lead
-short-circuit to supply voltage in the power cable
-contact resistance in terminals
-short-circuit to supply voltage in air conditioning (A/C) pressure sensor power cable
-short-circuit to supply voltage in fuel tank pressure sensor power cable
-short-circuit to supply voltage in accelerometer power cable
-defective atmospheric pressure sensor
Signal too low
-short-circuit to ground in signal cable
-short-circuit to ground in power cable
-open-circuit in power cable
-contact resistance in terminals
-short-circuit to ground in air conditioning (A/C) pressure sensor
-short-circuit to ground in fuel tank pressure sensor power cable
-short-circuit to ground in accelerometer power cable
-defective atmospheric pressure sensor
-defective air conditioning (A/C) pressure sensor
-defective fuel tank pressure sensor.
-defective accelerometer.
Signal sporadic:
-loose connections
-contact resistance in terminals
-defective atmospheric pressure sensor
-defective air conditioning (A/C) pressure sensor
-defective fuel tank pressure sensor.
-defective accelerometer.


Fault symptom[s]
-poor performance at high altitude
-can cause starting problems at high altitude.

I would check the connections to the sensor first and the wiring local to it.

Good Luck!

[SIAMBLUE]

I had the same problem with the Baro sensor,So phoned around and looked up on the net,None to be found,so i guess this to be a prob on these cars,
The guys at Lea valley motors sourced me one out from a vauxhall astra turbo,as they are exactly the same part except the connector is different,All i did was to cut and solder the new wires in,I could've crimped it if i wanted too,so now it has a sensor that cost £40 instead of volvos £100,
My light went off as soon as i fired her up.