Warning Light........Whats wrong???????

[TomW]

Re. my 1996 850 2.5 litre Automatic, the warning light on the right of the dash situated between the "service" and the "tracks off" light has come on. Theres an orange box with a green triangle in it and in the triangle is an inverted Y. Does anyone know what this signifies?
Many thanks
Tom

[Chris_Rogers]

It's the good old Lambda Light.
There's something wrong with the engine management system.
Have you got the 10V or 20V model?

[TomW]

Hi Chris,its the 20v model.
Tom

[Chris_Rogers]

Tom,
The ’96 B5254S (20V) version uses the Motronic 4.4 engine ECU.
There is no way to manually read fault codes from this but it’s the only 850 that’s OBDII compliant, so a generic fault code reader can be used.

So the options for reading the fault codes are:
Take it to the dealer.
Or find someone with a Volvo Scan tool or OBDII reader (If you’re near the South Kent coast I can help you).

The most likely problem is the Pulsed Secondary air injection system, the air pump can fail due to exhaust condensate getting into the air pump.
This is due to the non-return valve leaking. So if that’s you’re problem it would be best to replace the valve too. I think an improved valve is now available.
Procedure for fitting is at Volvospeed.com.

Chris

[TomW]

Thank you Chris.
If the problem is what you think it is, its Friday night and I cant get to a dealer. Might it be ok to do a 250 mile trip on Sunday without doing any damage? How urgent is it I get this seen to?
Thanks again for all your prompt help.
Tom

[TomW]

Chris
Forgot to tell you I had car converted to Gas 18 months and 30k ago. Might running on gas have cotributed to the condensation fault?

[Chris_Rogers]

Tom,

I can't really answer this a I don't know what the fault is, I was making a guess, and nor will anyone until you have the codes read.

My limited experience of gas is that the extra complication/expense of conversion with an electronically controlled engine is just not worth it. But that's just my veiw.

Basically I would say if you're not experiencing running problems and the cars not in limp home mode (you'll know if it is) then it's OK to run it. But you must make that judgement yourself.

The air pump should run from about 20secs after you start the car from cold, it's sounds like a hair dryer. If that's not happening then it's a fair bet the pump or it's controls are faulty.

Chris

I had this problem about a year ago on my 1996 T5 Auto. The main dealer traced it to a split in a pipe which was letting additional air into the air/fuel mix which the ECU couldn't compensate for. Unfortunately I don't know which pipe it was, but he fixed it (apparently it's a bit fiddly) and it didn't cost much.

Geoff