1992 960 Cruise - inoperative, no codes

Post by **VCA** » 10 Mar 2008, 11:08

One of the cars I care for, a '92 960 has never had operable cruise control...and I only got around to looking at it this weekend. I checked most of what I can: vacuum lines are good and hold vacuum, brake pedal switch tests okay with a multimeter, vacuum pump runs when removed and manually connected to power...

...however, still no cruise. I found that position 2 on the "B" diagnostic link connector is for the cruise system -- I connect it up, and no codes at all! Not even a 1-2-2 which I would have at least expected. Fuses are good, and the module has power at pin 11 with the key in II and signal at pin 7 when I step on the brake. Before I go throwing parts at it, does this sound like a dead cruise control module to y'all?

Post by **billofdurham** » 11 Mar 2008, 13:37

It is my understanding that the '92 960 only has one diagnostic box and it is not directly accessible by the cruise control system.

There is a short wire beside the cruise control box and this has to be connected to the diagnostic box lead using a jumper lead.

The codes are not read in the same way as those for engine faults. The testing is done by activating the components one by one and seeing from the response code if the control unit has received a signal from the component being tested.

If you do not have the method for running these tests I can post it here for you.

There is no code 1-2-2 in the cruise control checks.
Bill.

Post by **VCA** » 11 Mar 2008, 16:09

Hi Bill, thanks for the response. Reading VADIS indicated that cars equipped with a "B" diagnostic link connector box underhood (such as this 960) already have the cruise control diagnostic wire routed to port number 2 of the "B" DLC box (which in this car has both a wire and socket at that location). I will pull the the driver's side kick panel again and verify that there's no loose wire for the DLC.

Assuming I don't find one, would a diagnosis of dead module be a decent place to start?

Thanks!

Victor

Post by **billofdurham** » 12 Mar 2008, 04:04

I was working from memory, which is quickly fading, of my '91 960 when I said there was only one diagnostic box. It is all I can remember using.

I have looked at Vadis and, from what I can see, it is geared to the Volvo scan tool. The method I have for component tests relies on the on board diagnostic unit.

I shall also apologise for saying there is no 1-2-2 code in the cruise control DTCs. I should have said there is no 1-2-2 code in the component tests.

Bill.

Post by **VCA** » 24 Mar 2008, 15:13

Well, waddya know...dead module! I found an auto recycler that thought Volvo P/N 3523880 was a headlight relay and sold it to me for $19. I just installed it, did a quick diag and got a 1-2-2 (good sign, given this case's history). I took her for a quick test drive (won't have the chance to take her out on the expressway until tomorrow) and I could set speed and it held it (for the 5 seconds I could let it go in afternoon traffic before stomping on the brake)...parked her, and now she's showing a 2-1-2 diagnostic code after the drive.

Is it vacuum pump replacement time already?

Does anyone have any tests I can perform on the vacuum pump to test its condition?

Post by **billofdurham** » 24 Mar 2008, 16:34

I hope this is of some help.

Bill.

Post by **VCA** » 26 Mar 2008, 10:10

Thanks for the help, Bill! Between that and my wiring diagram I ohmed out the pump, found it had an intermittent ground fault (failed the tap test), swapped it out with a junkyard part ($15) and mother now has cruise control for the first time since she bought the car 5 years ago

Pity these cars don't have a "Cruise" light on the dash, or cruise controlled by the ECM (so the transmission won't hunt when cruising around 40-45mph) -- even my old '88 Buick had that

Post by **billofdurham** » 26 Mar 2008, 13:12

Glad all turned out well.

Thanks for the update.

Bill.