Garage can't get my Volvo 850 out of limp home mode. on 1994 Volvo 850

My car has been going backwards and forward to the garage for weeks as it needed a new mass air flow meter. That has been changed but the garage can't get the car out of limp home mode which as I have to have it back for work three days a week. It's costing me a fortune in petrol but I can't afford to take it to a Volvo dealer.

From what I have found out so far, it looks like once they have fixed the problem it should clear the codes and be ok, but they just can't get it out of limp home mode.

I'd be very grateful if anyone has an answer for this.

Asked by for the 1994 Volvo 850
This vehicle has a limp home mode for the transmission, which will cause it to start in 3rd gear, but the engine management system will not go into a limp home mode.
I would have all the codes checked, recorded, then erased. Drive the vehicle and recheck the codes. Post the codes here and I can give you further info, but I need to know what codes are being set in the engine and transmission modules at this time.
Also, do you have an automatic trans? Turbo?
Thank you bretb.

They are trustworthy at the garage and that's why I use them, but they didn't even know the car had an onboard management system until the Volvo secondhand parts supplier I use told me. So I guess they can't even be sure that it is 'limp home' method. The car is manual and there doesn't seem to be a problem with the gears and it drives ok but sluggish with a smell of petrol and uses about double the gas which is now £1.09 a litre. This has been going on for weeks, as I am a market trader, along with all the constant rain has virtually bankrupted me.

They have not been able to clear the codes by disconnecting the battery or any other way. The only code it shows is something like 021 or 121 (if my memory serves me right) which is supposed to be the mass air flow meter. They have changed that, but there is another one on the way in case the problem is that the MAF is faulty and that's why they can't clear the codes.

I have spent a few hours searching on the internet and have seen references to something called "winter mode", and it could be the thermostat, ignition or something else 'behind' in the MAF direction but nothing specifically directly relating to not being able to get the codes to clear, so it looks as if that is not an issue with these cars.

The garage have taken apart and cleaned the carburettor and choke, and have tried just about everything but can't get to the bottom of it. Then they are not familiar with this model of car. They don't think there are other problems, and they think that once they can clear the codes (realising that they might not be able to because there is another problem) and get it out of limp home mode, the car will be fine.

As I live a bit out in the sticks I am not looking forward to having to drive the car for a couple of hours tomorrow there and back to a Volvo dealership where for £40 they will put the car onto their computer, but even then they have said can't promise it will diagnose the problem. My funds are very limited and the car has been eating money for a few weeks now.

I'd be very grateful if you can throw any light on this.

Oh and it is a 20 valve 1984cc.
Hi Alice,
First of all, you're not in Virginia, are you?
My knowledge is based on the US spec 850, so I may not have the most accurate info, but I will try to help anyway.
"Winter Mode" is for Automatic Transmissions only, so you don't need to worry.
While your garage may be trustworthy, they may not be as qualified to address this problem as they could be, so taking it to the dealer may be the right choice, unless there is another independent shop near you that specializes in Volvos.
The code was probably 1-2-1, and that is for the MAF Sensor circuit. This means that the MAF sensor may be bad, but there are other possibilities as well. The electrical connector, wiring and the engine control module are all possibilities.
What you are referring to as "Limp Home" mode is your engine running very "rich", which means the air/fuel mixture has way too much fuel and not enough air, and this leads to poor fuel economy.
Please let me know what the dealership finds, especially all the codes they pull out of the computer.
Good Luck

No I am not in Virginia, I am across the pond, but we were friends once and my sister been a good US citizen since 1969!

Thank you for your advice which I will pass onto the garage. I will let you know what the resolution is.
3 answers 6 comments
Hi Alice2,
I am a former Volvo tech, had about 25 years in the dealer and I might be able to help you. First of all even the European cars are all fuel njected, for this year model, none of them had carburators. What they have is an air mass meter and a throttle body. The big deal is whether or not this is a Turbo first of all. If the turbo charger has gone bad, or if the vacuum actuator for the turbo is siezed up it will kill the power in the engine and you will feel like you have an anchor behind the car. Second if you have a stick car then I doubt it has a turbo charger as Volvo didn't like to put Turbo's on straight stick trans cars. There were some other issues with these cars. They have a metal fuel filter under the car on most models that has a paper type filter material inside it. I have seen these where the paper inside collapses on the older models and blocks the flow of fuel. So have them check the fuel flow and the fuel pressure at the injector rail, it should be around 30 psi. The last thing has to do with the fuel pressure regulator. I have seen these go back and what happens is the diaphragm inside collapses and will block the excess fuel pressure from returning to the tank causing a very rich fuel mixture and flooding the engine. One other thing is a must and that is to look at the ignition coil. Volvo had a problem with the coil arcing to the metal frame around the coil and when the engine starts to get up to speed the coil arc's causing loss of power to the spark plugs and missfires. This is evident by white around both sides of the coil on the metal frame by the coil windings. I know this is a lot of technical mumbo jumbo but take it to the shop you have looking at it and tell them to check out these things. Also know that clearing the codes should clear any limp home mode. Make sure if you disconnect the battery to get the radio code to reset it from the dealer if you do not have it. You only have 3 chances to put it in or the radio will be locked out. Thats another story. I hope this helps, have them check the timing belt also to make sure the car is in time. Good luck.
Dear johnnyk17

Thank you so much for your response. It happened to be very timely because this ended up going on for six months with the car going backwards and forwards and two days ago I went to see the garage about some compensation. I reckon it has cost me around £500 just in extra fuel as the car has been running on double petrol for six months. I am a market trader and needed to use the car no matter what.

I must have taken the car to the garage at least 25 times and altogether I reckon it cost me upwards of £2,000 in lost earnings, etc. not to mention wasted nerves as it ended up driving me up the wall.

In January I took it to another garage where I had to take it about five times and ended up costing £450 in labour, parts and taxes to sort it out, just about what the car was worth.

Naturally I had a bit of a gripe with them as well, in that they should have told me the engine was destroyed before I spent another £450 on it.

They said that there was no real way of knowing that until they had investigated and tried replacing the various parts. They changed the mass air flow sensor, the EU temp regulator and repaired the wire to the computer, cleaned the very dirty fuel filter(!), then changed the fuel pressure regulator.

Lastly (which I would have thought should be firstly) they told me that running the car that long on double petrol had basically destroyed the engine so that it was 'breathing heavy'.

They seemed to be telling the truth, and seemed satisfied they had done a good job, so I think my real gripe is with the original garage. I'm going to see them tomorrow to see what they have decided they are prepared to do.

I will come back with what they have said in the next few days.

My (layman's) conclusion is that it was the fuel pressure regulator that was originally the problem, even though the computer said it was the MAF sensor. Possibly the fuel pressure regulator caused the MAF sensor not to work as I had three of those in the course of the six months.

I should have said they also changed the injector rail as that was out of place or something.
ya i bought a new mass air flow sencer from NAPA . still had the same proublem you have , brork down went to the dealer, he put a Volvo mass air flow sencer in its bin fine for last 3 years . the dears part was less than the bad one i got from NAPA.
they only $40.00 labor ,loluck
2x 850 owners