All engine gauges dead

[craigm]

Hi everyone,

I have what seems to be a unique problem with my 2002 Viggen Convertible. Last Friday morning, I started the car and none of the engine gauges came alive. The speedometer, fuel quantity, turbo boost, temp and tach all read zero and the odometer window is blank.

After searching the forums I don't see this particular failure. The status lights work, they all come up normally after engine start and then extinguish normally. There are no fault codes logged. The dash lights work fine, the DTE calculation on the SID appears fine and the Night Panel seems to work normally (only speedo lit, but reading zero). I checked all fuses (visually - I did not do a continuity check). The car seems to run normally. I tried removing the negative terminal on the battery for an hour with no luck.

Anyone have any ideas?

[Dave 2 93s]

Hi
I've had the gauges go and then return intermittently before. It turned out to be a break down of communication between the ABS control module and the Engine management ECU. Basically the electronics at the rear of the brake pump unit failed to communicate with the engine management system . So the instrument control unit received no information and therefore could not display anything. Although I think the red triangle ABS/TCR light lit up.

[craigm]

Thanks for the response Dave. You must be a great troubleshooter....that sounds like an impossible problem to detect. I'm still trying to figure out how to verfiy the ABS module is communicating with the ECU.

I had another development. The car is getting very difficult to start. My immediate reaction was a dead battery, but I load tested the it and it's fine. I even tried a second "known good" battery with similar results. The car turns over very slowly and often doesn't "catch." When it does start, it runs normally (14.2v on battery) and no codes.

I checked the battery connection to the starter and to ground. I'm considering pulling the starter to look at the brushes. Before I get to that, does anyone know if there is a relay that could be causing start and gauge problems?

[Dave 2 93s]

Hi
Top international trouble shooter with boy band good looks sounds good.
But the reality was, I took the car to an engine diagnostic God who used Tech2 to interrogate the electronics.

Hopefully below are some links to more info on the ABS pump assembly

http://www.bba-reman.com/gb/content....repair_rebuild
http://www.bba-reman.com/gb/content...._bosch_5.3_abs
http://www.aa1car.com/common_car_problems.htm

Hope this is of help
Dave

[craigm]

Well, I finally broke down and talked with a local Saab mechanic and he's guessing it's the ignition switch. He says a bad switch will cause the engine gauge and the slow cranking problem. I'll let you guys know how it works out.