960 24 valve 3.0 litre 1994 yellow flashing arrow

father ted · Post by **father ted** » 11 Dec 2007, 13:04

Experiencing auto box selecting get you home mode by locking itself in third gear for no apparent reason whilst the flashing arrow dashlight tells me so.
Has anyone else had this problem and what can be done.Engine, auto box and drivetrain in perfect condition except for this.I found that by switching ignition on and off several times it cleared itself. Yours, cant sleep!

Post by **MadeInJapan** » 11 Dec 2007, 14:39

I hope someone can help you. I am moving this to the correct section as it was posted in the FWD section.
Regards,
MIJ

Post by **billofdurham** » 11 Dec 2007, 15:36

You have quite rightly stated you are in 'limp home' mode when this happens. The transmission will not shift gears because it is not receiving electrical signals. If you try to start off in D you will be in 4th gear and in L you will be in3rd gear. You can move manually into all other gears but need to start in L to minimize transmission wear.

When this happens the Transmission Control Module (TCM) will store fault codes and you need to read them to see what has happened.

The '94 model has the diagnostic box in the engine compartment.

Take a look at this thread for info on how to use it:

https://www.matthewsvolvosite.com/chat/p ... c&start=12

For transmission checks use socket number 1.

This is a list of the transmission fault codes.

When I had my 960 this happened to me. I simply cleared the codes and it ran perfectly for the next 18 months.

Bill.

father ted · Post by **father ted** » 12 Dec 2007, 05:32

Thanks Bill, iv'e always been nervous about "fiddling" with TCMs, ECUs etc.so i'll give it a good coat of looking at first. Cheers mate!

danr960 · Post by **danr960** » 12 Dec 2007, 09:40

Most likely your PNP switch is fouled, it resides on the side of the trans near the down pipe of the exhaust sytem so heat wreaks havoc with it.

You can work around it, but the switch should be replaced/repaired as your trouble will only get worse. Eventually the engine will refuse to start because the TCM is telling the ECM that you are still in a gear other than park.

But to get going normally, with the engine off, key in ignition and turned to allow movement of the gear selector, try rowing the selector back and forth, thru the whole range of gears, do this 20-30 times. This can remove some of the dried out grease in the switch contacts and allow the trans to function normally. If this cures the trouble then it is the PNP switch.

A simple fix, is to remove the switch, marking it's postition as the bolt hole is slotted, pull apart, degrease and clean the contacts, regrease with a synthetic grease and reassemble, it fairly easy.

Let us know how thing work out, good luck.

DanR '94 964 333,000 miles (99,000 on the new engine)

father ted · Post by **father ted** » 17 Dec 2007, 05:51

Thanks for the info Danr .Have not got round to it yet but your diagnosis seems well founded as other Volvo men have also suggested same remedy.I will get back to you with results. cheers mate.

Post by **billofdurham** » 17 Dec 2007, 11:26

You will still have to read and clear any codes that may be stored.

Bill.