V70 XC 2001 throttle hesitation

Japedo · Post by **Japedo** » 05 Feb 2010, 12:27

My wifes XC has 155miles on it now, recently there is a hesitation of between 1 and 3 seconds when you press the accelerator.
Is a real pain while driving in town and trying to pull out into traffic, as you could imagine.
I don't have any ETM codes, but the digital message screen is reading "engine system service required" and "engine system service urgent".
Anyone have any ideas, I think it is trying to tell me something.

Curtis

Steely · Post by **Steely** » 05 Feb 2010, 18:36

Possible MAF problems. Have you read this?

https://www.matthewsvolvosite.com/forums ... =9&t=26833

Nice writeup by E170_Driver.

Japedo · Post by **Japedo** » 06 Feb 2010, 05:26

steeley- Thanks for the link on the maf info, however I don't think that is my problem. I haven't had any idiling issues whatsoever car starts great and runs smoothly.

I just have the hesitation with the gas pedal, like it takes a few seconds to comunicate with the car when I press the pedal.
This delay that I am talking about happens regardless of speed. It is quite a small delay while accelerating from a stop, and the longest delay I notice is while cruising at 50mph "2100 rpm" . When I pucsh the pedal from 1/4 throttle to 3/4 throttle at this speed the delay is atleast 3 seconds.

No transmission codes and the shifting is very smooth.

Anybody have something like this happen to them? Logically it seems like the ETM to me but there are no codes/ messages to support it yet.

Thanks

Japedo · Post by **Japedo** » 28 Feb 2010, 08:54

Anybody have any ideas here? I really don't want to bring this thing to the dealership.

I'm going to spray some electrical cleaner on the maff and see if that changes anything but it is working great other then that hesitation, as well as averaging 24.5mpg.

Thanks floks

Joe Hurless · Post by **Joe Hurless** » 28 Feb 2010, 19:13

Japedo wrote: I don't have any ETM codes, but the digital message screen is reading "engine system service required" and "engine system service urgent".

This would be easy do diagnose if you could pull the code that the check engine light is throwing (service engine soon=check engine). However, your problem sounds like and air flow issue or, very likely with your mileage, a bad coil causing a misfire.

If you can get that code, we can pinpoint it.

Post by **E170_Driver** » 01 Mar 2010, 18:46

Japedo wrote:Anybody have any ideas here? I really don't want to bring this thing to the dealership.

I'm going to spray some electrical cleaner on the maff and see if that changes anything but it is working great other then that hesitation, as well as averaging 24.5mpg.

Thanks floks

It could also be a vacuum leak with one of the hoses at the throttle body or leaking intake manifold (tough ones to diagnose)...

Jan

Japedo · Post by **Japedo** » 02 Mar 2010, 04:55

I don't believe it is a bad coil, ive had to replace a couple of them in the past few years on this car. But when they were bad it didn't cuuse a hesitation in the throttle, just ran really rough.

Maybe it is a vacume leak of some sort, cleaning the maff sensor didn't help at all. Does anyone know where I could locate a vacume hose diagram for a 2001 XC? I'll borrow my frinds obd2 reader and see waht the codes are. I know there hasa lways been a P0422 code and mybe the cat has gotten worse..

Thanks

Joe Hurless · Post by **Joe Hurless** » 02 Mar 2010, 20:40

Ok, it sounds like a large airflow leak. Either that or a bad air mass meter. I always check the connections of all the airflow and turbo hoses on the car before replacing the air mass. Sometime there will be a massive rip in a turbo hose that you can only see with a mirror. If all the hoses and connections look good, try swapping the air mass meter. Some shops, like ours, will install the part for you to see if it fixes it and trade you back if it does not.

Japedo · Post by **Japedo** » 18 Mar 2010, 15:32

My wife stopped at the dealer today and got them to read the codes, print a bunch of stuff out and maybe tell us what the problem is.
The surprising thing is that they did it for free! I was expecting atleast 80$ so im pleased.

This is what they found and it seems to explain my throttle hesitation.

ECM-9180 Accelerator pedal (ap) position sensor - faulty
ECM- 9530 Accelerator pedal (ap) position sensor - faulty signal
ECM- 958F Accelerator pedal (ap) position sensor - faulty signal
ECM - 959F Accelerator pedal (ap) position sensor - faulty signal

THey checked my ETM out and said that thier are no faults found for this system, I also got them to print out the service records and according to that the ETM was done at 78miles and I got the car at 88miles.
Hopefully my issues are directly related to the "accelerator pedal position sensor"

Anyone know an aftermarket sensor/pedal assembly for these cars? is it plug and play or do I need software to make it work. Thanks folks

Dealer quoted 192 $ for the pedal assembly with sensor.

Esnoyer · Post by **Esnoyer** » 22 Mar 2010, 19:57

You must have a great Dealer ,mine charged $118.00plus tax to read my codes, my ckeck engine light came on.. It was a vacume leak the gas cap was the problem It was replaced with a VOLVO CAP for about $35.00 !!!!!!