2001 S60 T5 Auto Trans 104,000mi

I am experiencing surging/hesitation on light acceleration, and to a minor extent during cruise. At times it feels like the throttle is being cycled w/o my input.

The idle is very smooth and consistent, however. I would remove and clean the throttle body unit and clean it, but usually an inconsistent idle is the first signal that a cleaning is needed, and I don't have that.

The surge/hesitation is much worse w/ the Air Conditioning on.

The Cruise Control is intermittant. The switch will often not make the "CRUISE: light illuminate in the speedo window, though when it will, the cruise control works fine, but usually quits in a few minutes. Sometimes re-starting the car will allow the cruise control to function again. Not sure if this is related to the condition.

There is NO "MIL" or "Check Engine Light" illuminated, though most of the time I get a yellow triangle warning, and a text message "Engine Service Required" (I believe it says). It sometimes goes out, though surge is still there.

I have not yet had my car go into the "Limp Home Mode" as have many owners with the warning apparently have.

I hooked up a Equus Innova 3100 OBD II Code Scanner to the car, and it is evidently not communicating with the ECM properly, because I get the "Run Monitor," but it ONLY shows the CC (Catalytic Converter) monitor, and none
of the other ones displayed or are blinking. I also do NOT get the "DONE" message which is supposed to tell the operator that the scan is complete. It shows "00" for Codes, which would indicate taht there are NO codes storred, though without the "DONE" I have my doubts. The scanner works fine with other vehicles I use it on, BTW, including other (older) Volvos.

I know there is a silent recall, of "campaign" for the ETM (Electronic Throttle Module) on the car (National Highway Traffic Safety Administration #06V441000), extending the warranty to 200,000 or 10 years, but am not sure if this is my problem. MOST 2001/2002 Italian Marelli ETMs have, or will go bad according to what I read.

I welcome any advice or counsel regarding this problem.

My closest Volvo dealer is 1.5 hours drive time away, so I'd like to be prepared when I visit.

Thanks,
Bob

 

Yours is another classic example of ETM failure so dealer shld change it for free.

 

Thanks-

I have now done a LOT of Internet reading and I believe you are correct.

Now, I need to research how best to get Volvo to install a new ETM before the car strands, or tries to kill me.

The car DID have the software upgrade for this condition 30,000mi ago in 2007 when the P.O. (my nephew) complained of un-commanded revving and stalling, but do not see a part was installed (I have the dealer invoice in front of me).

 

OK, I've done more observing, and have the symptoms nailed down a little better.

1) Dealer says unless the Check Engine light is on, and there are codes stored, I can forget them doing any "Free" troubleshooting or ETM replacement. The service manager says if the ETM fails, it REALLY fails. Nothing subtle about it.

2) If the car is shut off when hot, and sits 10-30min (so it heat-soaks), the engine surges/hesitates when it is restarted and tried to maintain speed or accelerate slightly. After 10-15min of driving, it gets better. Much worse if A/C is in use. Not too bad (just annoying) if the engine is started from cold and driven.

3) It idles super smooth, and accelerates very smoothly if considerable throttle is added.

4) It does it even if the Cruise Control is controlling the throttle body, so I don't think it is the pedal sensor.

5) No more text messages appear ("Engine System Service Required"), and no codes, either.

Does this "ring any bells" as far as sensor or control problems?

Thanks,
Bob