This is maybe a follow up to my earlier thread about the lockup solenoid. The car drove fine for a few days since doing what basically amounted to a transmission flush and filter check, while having a look at the S-L solenoid while it was out. Unfortunately it didn't last. The lock up solenoid started to act up just a bit, the car went into limp home mode the next day (only once though) and currently it gives 3 codes.
1-4-3 Oil temperature sensor circuit, open circuit
3-1-3 Faulty signal from gear position sensor
in one day, then
One for the S2 solenoid (forgot which) on the next

The gear position sensor one makes sense because the wife said the car would not start, but would a few minutes later. The up arrow didn't flash until the S2 solenoid fault hit.

I'm planning on how to move forward. What should be replaced first? Maybe refresh or replace the PNP switch? In my opinion the transmission itself is suspect because it's always shifted 3 times quickly into/out of 3rd/4th under light acceleration... unless that's controlled by the S2 solenoid and then the computer may be telling the truth with its latest code? Now it's either entering 4th or locking the torque converter with several loud ticks. Other shifts are just fine though. I have plenty of time to figure things out since this car is no longer anyone's daily driver.

One of the worst things to troubleshoot is two or more problems at the same time..

A non-start certainly points toward your PNP switch - they tend to act up as the weather turns colder.

I think that it can trigger limp home as well.

I would stop when the transmission acts up, stop and shut the car off, and try the row-the lever technique. Restart and see if that makes a difference.

Have you or she tried the row-the-lever technique when there is a no start?

Not yet... it's only happened once so far and like all good car problems it could not be replicated. I disassembled and cleaned the PNP switch sometime earlier this year.

Thanks for the weather insight though; maybe that's why it only happened one time on a really cold morning.

Put a newer 96-97-98 trans in it. Save yourself a lot of trouble. Pauli

Would a '96-'98 fit by itself, or would it also need a transmission controller or some other items to go along with it?

Everything is up in the air at the moment. The SO's new car was rear ended at a stoplight last weekend and now she's asking about repairing this car. It needs a new transmission, rear shocks, rear axle or wheel bearing service (haven't tracked down the sound yet), both rear door lock actuators, non-passenger airbag glove box insides, and dealing with a small freon and vacuum leak.

Dear Scuba Steve,

Hope you're well. An Aisin-Warner 30-40 (or 30-43) transmission - from a '96-'98 (960 or S/V 90) should have its own control module.

According to the Volvo Pocket Data Booklet - Cars (700,900,S90,V90,850,S70,V70, C70) 1991-1998, p. 102, there are pairings between transmissions and transmission control modules, for a model year or for a range of years.

The part numbers shown are for the transmission control module:
AW30-40:
1992-93...3515784
1993-94...9144038
1995........6848274
1996-.......9144365
AW30-43
1991-95...3515646
1994-95...9128859
1996-.......9148498

What I don't know is whether there's interchangeability between the wiring harnesses that connect the transmission control module to the transmission and to the rest of the car.

That is, I do not know - never having had a reason to look at these TCMs - whether all have the same connector format, and whether each wire at the TCM end of the harness goes to the same place on the car.

Perhaps an automatic transmission specialist can tell you whether you need to get the wiring harnesses from the donor car, along with the tranny and the control module.

Hope this helps.

Yours faithfully,

Spook