- Edited
Posts further down explain the issue.
1994 volvo 850 Blinking LCD, no fuel gauge, Missing VSS [solved]
Have you checked it's not just a blown globe?
The LCD blinks like it's trying to turn on but then goes to blank and only displays the clock. The transmission is complaining about a missing VSS signal which goes vss>cluster>TCM and the fuel gauge doesnt work/is stuck on empty but the fuel light is off. All the needles work fine using the diagnostic test (3 button presses) and the instrument cluster is throwing every possible DTC. There's a little chip mounted on the little LCD daughter board that I believe is fried. Can't really think of anything else that would be causing the problem?
The wiring diagram shows that fuel, temp and speed all go through a chip. Although i'm not sure which chip as the rest of the cluster has a few soldered to it so it may be better to just replace the whole thing.
Yep probs easiest to chuck a cluster in ill check my stash at work
Cheers.
- Edited
Here's some pics of the cluster as I know that later year models vary with PCB design.
I have a separate boost gauge installed anyways. I don't think the non turbo one's would differ electronically as the turbo gauge just runs off a vacuum line with no electronics but I'm unsure if there's any other differences between them?
- Edited
Circuit board should have a part number on it, VDO992645949
2 months later
If you're having similar issues the whole cluster, not just the LCD unit, needs to be replaced. Managed to get one through berry motor group. They we're super helpful. The fuel gauge is functioning again as is the trip computer and no more shoddy shifts or warning light from the transmission. Hooray!
Edited the title so people with the same issue can find it on web search.