2000 XC70 - A little help with diagnostics, please?

dislusive · Post by **dislusive** » 10 Jun 2009, 10:15

Hi all.

Wondering if some of you could take a look at this and let me know your opinions of the issue before I throw more parts at this car.

My original issue was that the car had a surging idle, the RPMs would drop down to about 600 RPMs, and back up to 900, quickly. This would only happen while the car was idle, or stopped (red light, stop sign, etc...)

The CEL kicked on shortly after with the following codes:
P0422
P1237
P0302

I wanted to rid of the misfire, could have caused the cat code, so I replaced the plugs, coils, and turbo control valve. I also replaced the filters (fuel, oil, cabin, air).

The CEL went away. Now, the car runs rough as soon as you start it, but quickly smooths out after a few seconds, and the RPMs drop still on idle depending on the driving conditions:
- If the car is warm, but the car was driven lightly (not taken over say 2500 RPMs the entire trip) the idle drops to about 750RPMs then back up to 900RPMs (only when idle!) without a hint of the car dying.
- If the car is warm and has been pressed, (say over 2500RPMs, even for a second up a hill) then when at idle the RPMs drop to about 250, seems to want to stall, the arrow light flashes (like you were in a lower gear), and then the car recovers right away. Also, when coming to a stop, the car seems to down shift kind of hard, maybe late? Not like a slip though. Also, the RPMs drop from 1500 RPMs to under 900 in an instant, it's not a steady decline.

The latter only happens once, then the former is repeated until the car sits for a minute or two and the idle smooths out. This can be replicated a time or two by stepping on the gas (taking the RPMs up to 2k+) and letting off the pedal. (even with the car in park).

Sound like it could be a MAF, ETM, or O2 sensors, or maybe something else.

Opinions please?

Post by **vegasjetskier** » 10 Jun 2009, 10:21

Sounds like the ETM to me. What color sticker is on it?

dislusive · Post by **dislusive** » 10 Jun 2009, 10:33

White - the original ETM.

Post by **vegasjetskier** » 10 Jun 2009, 11:05

Have you tried to get a new one under warranty from the dealer?

dislusive · Post by **dislusive** » 10 Jun 2009, 12:04

I called the dealer service department, they stated they had no idea what the problem could be. They want to get one of their techs to duplicate the issue and read the codes (cost $100). Before they can do the warranty repair, they will need to clean the throttle body first (cost $250) and see if that works. This is assuming they even consider the ETM to be at fault.

The CEL or ETS lights are not illuminated, I will see if I can read any codes with a reader.

C@lvin · Post by **C@lvin** » 10 Jun 2009, 16:16

For what it's worth, here is somthing I wrote back in October about my 2000 V70 Throttle Body experience:

I experienced an intermittent ETS warning light for 4-5 days (but with no drivability issues) prior to taking my V70 to the dealer to pull the DTCs on 09/25. The light was actually OFF when I dropped it at the dealer.

They informed me that the TB was bad and they would request replacement under the Extended Warranty from VNA but that the part was backordered with an unknown ETA. There was no charge for this diagnosis which would have been $75 if it had been determined not to be caused by TB failure.

The dealer never mentioned anything about having to clean the TB or clean/replace the PCV breather components prior to a final diagnosis although I have read that other owners have been required to have these procedures done at their own expense prior to a final TB failure diagnosis. Thankfully, that was not my experience.

The dealer called yesterday and said the ETM was in. They replaced it today. Altogether, it took two weeks to get the part in (due to the alleged corporate-wide shortage) once they pulled the codes and got approval from Volvo. I parked the car during this time as a safety precaution and if the part had not come in soon I would have requested a loaner as suggested by MIJ.

Apparently, there are ETS codes that can be pulled by the Volvo system even if the CEL is not on, whether they are historical, pending, or otherwise. And apparently, if it's the right code, the system or the VNA protocal automatically calls for throttle body replacement.

Considering my past experiences with this dealer and the negative posts I'd read about other people's experiences with ETS failure I was shocked that it was so easy.

If your ETS is failing and still under warranty, I hope it goes as well for you. The warranty does end 10 years after the date the car was "put into service", so I imagine you are pretty close to the limit if not past it.

Good luck!

dislusive · Post by **dislusive** » 15 Jun 2009, 11:13

It turns out it is a yellow sticker ETM - I swore it was white when I checked it (must be old age creeping in).

I decided to clean the MAF, since I have seen numerous posts stating that is the next part to go after the ETM is replaced. I'm just not sure when it was replaced. It runs 90% better after the cleaning.

It still hunts for idle for a couple of seconds when it's cold, but idles mostly correct the rest of the time. The idle still drops to ~500RPM on a hard stop, is this normal?, but doesn't seem like it's going to stall now.

I was thinking about replacing the MAF as a next step.

Post by **FlyingVolvo** » 15 Jun 2009, 18:47

My MAF is fine, but I have the rough idle on cold starts and the RPM dip when braking. I'm going to have to fix this soon and I'm sure you have the same problem I do. ETM.

dislusive · Post by **dislusive** » 15 Jun 2009, 20:57

Yeah. ETM woes...

Nevermind my last post. Just got back from a 50 mile round-trip (multiple places). The problem is worse than ever.

Doesn't want to start every time. Slowed down to park and the whole car literally surged forward as the RPMs jumped from ~250. This could have easily of caused an accident. I was going about 2 MPH about to come to a dead stop when this happened. If there were a car in front of me, I would have hit it. Scary stuff!

The RPMs are dropping even when I let off the gas now, like driving down the highway and going 50MPH. Not quite to stalling, but a lot of hesitation.

Ordered the MAF earlier today (will be here Wednesday), will replace that and off to the stealership it goes. Just rolled over 98k miles. No codes.

dislusive · Post by **dislusive** » 18 Jun 2009, 15:55

Replaced the MAF yesterday, ran fine for a short trip.

Today the problem is getting very bad with the dipping/surging. Afraid of wrecking into something, so safety is a concern. Had AAA flatbed it to the dealer.

I feel my bank account lighter already. *cringes*