2000 Volvo S70 GLT Rough Idle, No CEL

gravyman · Post by **gravyman** » 06 Aug 2015, 22:06

I've had this problem for a couple months now, constant flashing check engine light, On a warm engine, the idle is sometimes very rough (problem isn't always present) . Sometimes not at all. When it's acting up, it's acting as if I have a bad MAS or ETM (fast fluctuations in the RPMs from 650-900 or so -- often shaking the car while in gear) . Not sure if this is related, but when I give a very slight throttle, the car acts as if it's going to die, drops to about 400 RPMs, jumps up to around 1,200 and then recovers.
This is a video of (Not my car) how the idle is acting :

Went few days ago to a local Volvo mechanic and got the codes read at a local Volvo mechanic, said I had a misfire on cylinder 2 and a bad MAP sensor on the turbo, though there were codes for many other problems as well. He told me the others weren't an issue as they were caused by the computer throwing false codes.

So today I changed the MAP sensor, the coil pack and the spark plug for the cylinder, and cleared out the check engine light. It ran great for a bit, but when I got home tonight the rough idle started back up. There is currently no check engine light. After shutting off the car and starting it back up, the idle was back to normal.

Not really sure where to go from here. Any ideas?

Post by **abscate** » 07 Aug 2015, 01:02

Try unplugging the MAF sensor next time the idle is rough. You do have the notorious MM electronic throttle body on this car which dies at about 100k miles, too.

gravyman · Post by **gravyman** » 07 Aug 2015, 14:11

A little more background: I've owned the car for about a year now. It currently has 162k miles. I am not sure when the last time the Electronic Throttle Module was cleaned or replaced.

Today I disconnected the Mass Air Flow sensor like you suggested, to no avail. I also noticed the ETS light will flick on during ignition and will immediately shut off once the car is running, which has never happened before. Am I correct in assuming that there is a fault in the throttle system? Or could just be the computer running a check on the ETS?

Within the next week or so , I'm most likely going to pull an ETM from another 2000 S70 GLT in the local salvage yard, clean it out, and replace it with mine. From what I've researched, they don't require a software download so switch between cars like that?

Post by **RussB** » 07 Aug 2015, 17:32

Check this out,

http://xemodex.com/us/knowledgebase/etm ... 1999-2004/

I installed a xemodex ETM in my 2000 and it cured it of its ails

Post by **abscate** » 07 Aug 2015, 19:23

gravyman wrote:A little more background: I've owned the car for about a year now. It currently has 162k miles. I am not sure when the last time the Electronic Throttle Module was cleaned or replaced.

Today I disconnected the Mass Air Flow sensor like you suggested, to no avail. I also noticed the ETS light will flick on during ignition and will immediately shut off once the car is running, which has never happened before. Am I correct in assuming that there is a fault in the throttle system? Or could just be the computer running a check on the ETS?

Within the next week or so , I'm most likely going to pull an ETM from another 2000 S70 GLT in the local salvage yard, clean it out, and replace it with mine. From what I've researched, they don't require a software download so switch between cars like that?

OnME7 the software and versions have to match or else it is a brick. I believe the ETS light goes out after the engine starts. If it's flickering, you've got and ETB problem