1997 S90 power fluctuating at cruise

ML11 · 2023-09-26T01:04:55+00:00

Hi...at least once a week the red arrow warning light comes on telling me there is a gearbox problem. It normally goes away after 1 or 2 short drives, but no...

ML11

A good Volvo specialist repairer thinks it is quite likely to be the Speed Sensor on the tranny.....considering that the OBD code is "Speed Sensor A" then I'll replace it just in case...problem is, when I looked online there are all manner of different shaped units.
Can anyone advise what the one on my S90 looks like or a part number?? I've looked at straight ones, T-shaped ones, L-shaped ones <sigh>
Is this the one??
https://www.fruugoaustralia.com/speed-sensor-for-volvo-10r035882-10r-035882-21660485-22677703-car-auto-accessories/p-200854124-427273470?language=en&ac=google&asc=pmax&gclid=CjwKCAjwnOipBhBQEiwACyGLutSY3rXOYTAw5bljiN5sD8tJNoXBqowRamQU81cTixBxgzy0-pGJnxoC4YYQAvD_BwE

Major Ledfoot

ML11 The speed sensor you want for your AW30-40LE is NLA from Volvo.
It is p/n 3515641.
Berry's in Melbourne might have used one, or you may have to go with an alternative.
See my post in this thread (below) from a while back.
https://ozvolvo.org/d/16651-16651/7

ramrod

You will want a genuine speed sensor, if they are available.

I’ll have a look

ML11

ramrod
Many thanks, Ramrod.

ML11

Major Ledfoot
Will do - thanks for the help!

ramrod

Bob is right,

The sensor is no longer available unfortunately

Sorry

ML11

One of the problems looking at Forums is that when someone has solved a problem - they happily disappear, and other poor souls further down the line don't get the benefit of whatever the fix was !! So I'll do my best not to do the same, and add to our collective knowledge - hopefully 🙂)
The story so far.....
Installed a Speed sensor (LHS of transmission) from Berry MG which removed the fault code, but the engine light remained. Suddenly a new code appeared " ECT problem" ...
When I researched this - I finally found the answer to the original problem that kick-started this whole rabbit hole I've been down, which is the high speed fan staying on after shutdown, and full-time on while driving. This fellow gave the clues that tied everything together https://www.volvo-forums.com/threads/97-960-coolant-temperature-sensor.38111/
Now just waiting on a new ECT sensor and hopefully that is the end of the trail?? As an ex computer tech, I know that circuit boards (esp in cars) dry out with time, and we get what we called WIF - Weird Intermittent Failure. A case in point, my previous 740 would start fine but "kangaroo" down the road at no more than 10 kph !! Took a Volvo guy quite a long time to track down the fault - which was fixed by sending the fuel computer away to have the solder tracks re-flowed. Worked like a charm after that!!
Hmmmm, maybe after 20+ years we ought to remove all computers for re-flowing? Might save a world of hassles? 🙂)

Major Ledfoot

The ECT failing after 25 years isn't too much of a shocker.
Be thankful the S90 has only a handful of modules.
Our 2010 S80 V8 has a total of - wait for it - 57 goddamned modules, which control everything from engine to bum temperature of the seats. It's complexity taken to the ridiculous. The wort part of all is that it appears Ford did the wiring diagrams and they're nowhere near as good as the Green Books for the pre-Folvo stuff used to be.
Glad to hear you've fixed the problems and how you've reported back. The knowledge base of 960/?90 cars is very small compared with redblock engined cars.

ML11

Major Ledfoot
57 !!! OMG..... thanks for the tip - I'll stay with the 900's..... 🙂

Major Ledfoot

JFTR -

ML11

Major Ledfoot
What a nightmare !!! I sure hope you at least enjoy DRIVING the car - rather than under it 🙁(

Major Ledfoot

ML11 CAN bus is the work of the devil, and I leave its care to experts. The V8's wonderful to drive, but I dare not wave a spanner in its general direction.
I reckon the 960/?90 level of electronics is the correct balance - it does enough to keep things convenient, but not so much as to be a domineering PITA. ABS module, ECU module, and transmission control module is plenty.

ML11

Eureka !!

The mechanic fitted the new ECT sensor under the thermostat - cleared the codes, and…..nothing !!

No warning lights, no misbehaviour, no fans staying on when they shouldn't…..just blissful nothing!!

First time nothing ever felt so good 🙂

Thanks to all for your good help and taking the time to dispense it.

Ex850R

ML11
Excelletnt1
DAMN IF I DIDNT HAVE THAT HAPPEN TO one of my Whiteblocks , ide forgotten about the ECT....

« Previous Page