2000 Volvo s70 t5 48k sluggish acceleration off the line Topic is solved

[Johnthevolvoking82]

Hi guys I have a 2000 Volvo S70 t5 48k
The problem is poor acceleration I’ve had a few of these cars in the past and they’re very quick this car feels like it starts out in second or third gear I hooked up the OBD and got code p1631
I would appreciate some help guys please

[abscate]

Hello fellow NYr

That 1631 code is a communication error between engine and transmission management modules, or computers. Your AUTEL code reader always get the right codes but doesn’t always get the right text.

The car will then stick the transmission into “limp mode” which feels like you are starting in 2 or 3 gear, because you are
Doing exactly that!

Inspect wiring and perhaps reseat the modules if you are comfortable with that

[scot850]

Your ABS light is not on by any chance? That can throw out the speed sensor signal and can cause trans issues/limp mode.

The P0442 is a minor Evap leak but that should not affect your car's running. Probably the 'J' hose at the carbon filter under the RH rear passenger seat under the floor. Either that or the gas cap seal being bad.

Like abscate says, corrosion can occur with the contacts on the TCU and ECU. When this happened on one of my cars it threw many error messages including the speed sensor signal. I had the dealer diagnose the issue for me and they removed the TCU and ECU, cleaned all the contacts, reset the system and car was good after that.

Neil.

[Johnthevolvoking82]

How do I reset the modules and should I replace the gas pedel

[abscate]

No for the gas pedal replacement. Try clearing codes first and see if they come back

[Johnthevolvoking82]

I reset the codes and then car had hard time starting back up but code came back I also disconnected the Meg terminal and also touched it to poss and still code came back

[scot850]

Re-read your post.

So you have 2 codes, the first one is not clear on the picture the P1631, as well as the P0442.

As your car is the 2000 model year it is more likely the ETM unit that is failing. For some reason I thought your car was a 1998!?

As abscate says, I would agree that it is unlikely to be the throttle pedal is the issue. Like anything it is possible but I do think unlikely to cause the car to start up in 2nd or 3rd gear.

For the car to want to start in a higher gear the TCM has to be seeing a load condition that would tell it to start in 'winter' mode. Does your car have the 4 speed auto trans, and does it have the WINTER button in front of the gear shift?

Neil.

[Johnthevolvoking82]

I sold the car couldn’t deal with it anymore

[kallekula]

That’s too bad. Looks really good in that picture!

[abscate]

Ooof. Someone just scored a great deal