Lamba/Check engine light has come on 1998 S70

[214299]

The car drives perfectly fine no issues. The coolant level and MPG are not falling.
There is no misfire or stall etc. The scan coolant graphs show a saw tooth wave oscillation from normal to overheating temperatures.

So I’m going to try changing the ECT sensor. One on order from autodoc.co.U.K. and while I’m there I will change the thermostat. I have an OEM stat in the garage just waiting. As far as I know the stat is the original i.e. 24 years old.

If that doesn’t work I’m into a right sh#t storm of faffing about.

[214299]

I changed the ECT sensor and the thermostat while I was there as it was the 24 year old original. The car continues to runs like a Swiss watch or is it a Swedish watch.

I cleared the codes and scanned again and happy days the Engine Coolant signal faulty, code has cleared no DTC’s anywhere.

Trouble is the Lamba/Check engine light is still on.

So I can only assume there are 2 or more faults. Some of which the scan tool does not cover.

So what’s the next step ?? Any ideas anyone. Thanks.

Will the light come on for a non scannable fault, I’m not sure.

[214299]

Reading around the topic has told me that as this 1998 S70 has Fenix 5.5 ECU’s even though the code is clear the light remains on until you switch it off using a flash code reader.

So I will try that.

[214299]

Still no luck. I’ve tried 3 flash code readers and with all the LED stays on when the ignition turns to position II.

I give up, the next move is take it to an auto electrician over the age of 50.

[Derek UK]

Is this too simple? Works fine on my 1999 V70.

https://www.youtube.com/watch?v=EI-CRWqoO6U

This appears to work on Late P1 1998 - 2000, but not 850 and P2/3 models.

[SteveSarre]

Hi 214299

For the tick at the timing belt end, have a close look at the clutch on the end of a/c compressor (opposite to the battery end).

I think it can make a tick at about that interval.

I think it can happen if there is not enough a/c gas in the system - it will engage then disengage. Or possibly if the clutch springs are worn it will engage then give up. You may be able to affect the tick by turning the a/c on and off at the climate control. Believe a/c is always on when screen demister is on.

I recently bought a couple of these OBD dongles which work fine, but I cannot easily verify that they will work on your 1998 10v

https://www.ebay.co.uk/itm/144060054970

I use it with the free Torque app.

At that price it is worth having one knocking around IMHO.

HTH
Steve

[Barnoluk]

Did you find an answer to this?

What do you mean you tried 3 led readers? You made 3 or borrowed 3?

These are home made lash up devices generally so surprised you had access to 3 if that is the right device you used

[Luxobarge]

Originally Posted by SteveSarre

For the tick at the timing belt end, have a close look at the clutch on the end of a/c compressor (opposite to the battery end).

I think it can make a tick at about that interval.

I think it can happen if there is not enough a/c gas in the system - it will engage then disengage.

Good shout on the A/C compressor clutch - these engage and disengage at about 10 second intervals even when the gas is fully charged, so a regular clicking in the area of the compressor is normal, in fact it's good news as it means your A/C is working fine! Try switching the A/C off and see if the clicking stops?

[4x4]

850 compressor cycling on and off. CLICK