Hi all,

I have a few issues which I think may be connected.
Firstly when the car is hot, stuck in traffic and on the highway etc, my speedo jumps up and down regardless of my speed, also happens when stationary in traffic when I first stop.
Secondly my transmission seems to change gears at the wrong time, not a major problem just creates a slight bumpy ride between first and second and possibly third gears.

My first thought is the speed sensor needs replacing, but could be something more expensive, may be the Electronic Throttle Module???

Timming belt was replaced and transmission was flushed recently, but has not affected this particular problem.

Thanks
2001 Volvo S40 1.9T
150,000 Km
Auto Transmission

 

Welcome to the forum.

Sorry about the problem.

Is any of the dash warnings turned on? If not, are there auto parts shops in Canada that provide free OBD-II diagnostic service? In the States, AutoZone and other shops do this for free.

The ABS module is also related to the vehicle speed measuring, system and there are speed sensors on the engine, transmission, etc... I am not privy to S40, so you may have to wait until S40 forum members reply, and if not, wait till a gentleman by the name of Moderator Tech replies to you. Moderator Tech is the top-dog of the forum.

Sorry I couldn't help you any better.


JPN

 

No I have no error codes or dash lights on, I own a OBD-II scanner so i can check on a regular basis.

I had my ABS checked out not that long ago (may be 6 months) and there were no errors then. Thats not to say its error free now.

Thanks

 

Hi nordx,

With your reply, I can only assume the throttle body needs cleaning, throttle control motor is having problem (if the S40 is equipped with DBW).

As to harsh shifting, did you check the condition & proper level for the transmission? I am not sure what fluid is used on S40 (850 uses Dexron-III/Mercon), but I assume you've done this check already, as youseem quite knowledgeable.

Please wait till other S40 members or Moderator Tech replies, since my knowledge on the S40 is very limited.

I wish you the best of luck,


JPN

 

I was thinking about cleaning the throttle body anyway, but seeing as you mentioned it, I got my finger out and actually did it. See pictures attached, mmm SHINNY!!!
In case you are wondering it was NOT shinny when I started.
Any idea how often this should be done??

I think in my preliminary drive around it has helped with the gear shifting a little and all round seems more responsive.


[IMG]local://upfiles/9572/CA34AAB73908474788CF19258193447E.jpg[/IMG]

[IMG]local://upfiles/9572/A47205F2375D4A9DBE200E7DE7055891.jpg[/IMG]

 

The harsh shifting might also be fixed by software.
But if there is a sensor on the transmission that is messing up that will affect the speedo as well.

 

Finally I got an error code, well actually two:
P0700 - Transmission Control Malfunction
P0722 - Second Transmission Speed Sensor Malfunction

I left my car parked for four days while away, came back, and guess what it would even shift into reverse let alone 1st until it had warmed up.

I'll see what the dealer has to say.

 

keep us imformed. Sounds like Tranny is done!