Gauges gone wierd
sverker
02-17-2014, 02:55 PM
I recently bought a 04 AWD with some minor issues to fix (AWD not working, ABS light on due to faulty rear right sensor). Yesterday I got a break issue with my 02 daily driver so I put the 04 in traffic to go get some spare parts.
I was driving along when I started to notice that I didn't agree with the speed the speedometer was showing, and after stopping at a red light it stayed at zero. When reaching my destination, which was close by, and turning off the engine I noticed that fuel and temperature gauges were not returning to zero position. When I turned on the ignition instead they used their current position as zero and continued upwards from there.
I physically verified that the engine was not unusually warm, no boiling coolant, normal fluid levels etc. and then dared to drive it home which was only like 15 minutes away. The speedometer now worked again but fuel and temperature gauges were offset by the same amount as they had started from.
When I got home I fetched my OBD-II bluetooth adapter to read the values from PCM, and temperature was at 90 degrees celsius as I expected. Being late for work, but also because I wanted to see how it was behaving, I drove the approximatly 20 minutes there while monitoring the values from PCM on my android phone. Temperature kept within the expected limits the whole time, and when parking I let it sit idling until it turned on the fans (AC on).
But while driving I noticed that the speedometer got stuck at 65 km/h and wouldn't move from there even when I had parked. It then looked like this:
http://www.abrahamsson.com/bilar/chevrolet_transsport/20140217_095635.jpg
When driving home I used the phone via OBD-II to get the correct values for speed and temperature, don't want to be without neither of them...
I've searched the forum but I haven't found anything similar. All these gauges gets their signal from PCM from 00 and up, someone wrote about replacing stepper motor but since all three started to act strange at the same time I'd more suspect a grounding issue, a bad soldering in the instrument cluster or something like that.
I was driving along when I started to notice that I didn't agree with the speed the speedometer was showing, and after stopping at a red light it stayed at zero. When reaching my destination, which was close by, and turning off the engine I noticed that fuel and temperature gauges were not returning to zero position. When I turned on the ignition instead they used their current position as zero and continued upwards from there.
I physically verified that the engine was not unusually warm, no boiling coolant, normal fluid levels etc. and then dared to drive it home which was only like 15 minutes away. The speedometer now worked again but fuel and temperature gauges were offset by the same amount as they had started from.
When I got home I fetched my OBD-II bluetooth adapter to read the values from PCM, and temperature was at 90 degrees celsius as I expected. Being late for work, but also because I wanted to see how it was behaving, I drove the approximatly 20 minutes there while monitoring the values from PCM on my android phone. Temperature kept within the expected limits the whole time, and when parking I let it sit idling until it turned on the fans (AC on).
But while driving I noticed that the speedometer got stuck at 65 km/h and wouldn't move from there even when I had parked. It then looked like this:
http://www.abrahamsson.com/bilar/chevrolet_transsport/20140217_095635.jpg
When driving home I used the phone via OBD-II to get the correct values for speed and temperature, don't want to be without neither of them...
I've searched the forum but I haven't found anything similar. All these gauges gets their signal from PCM from 00 and up, someone wrote about replacing stepper motor but since all three started to act strange at the same time I'd more suspect a grounding issue, a bad soldering in the instrument cluster or something like that.
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