oscilloscope eg velleman hps140 pocket scope
New here: Temp gauge failure
- Thread starter stevejg
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oscilloscope eg velleman hps140 pocket scope
TAKdriver
Active Member
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- Beside a field in Midlothian
Where are you in US ? I'll be over in July and September and have MV Faultmate : you'll want your gauge problem fixed before that but you never know with the P38 !
Would interference be a cause for gauge malfunction even though the wires to the cluster are receiving the proper voltage? What could cause interference?
An exhaustive Google search shows this is a very common problem, but no one ever updates their posts with the solution or fix if one was ever found!
you can also check voltage with a scope at same time.
I haven't looked at a RR wiring diagram, but a scope can show data in a wave form- it is possible that if there is interference the wiring would work- but the gauge wouldn't.
I would also check and clean all the earths- if you have a bad earth it can cause all manner of weird faults
an odd question, does the gauge work at all correctly with hot engine ign on and engine not running
Interesting. All earths have been checked, please see the rest of this trhead. The only time the gauge works is when it is plugged into diagnostics. Otherwise, when ignition is on or truck is running, the needle will move a quarter inch off cold into the blue lines and remain there. The red overheat light turns on and off like it should upon startup.
Datatek
Well-Known Member
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- Near Poitiers SW France
There was a diesel with exactly the same problem, turned out to be the sensor was the wrong one. With diagnostics, you can drive the gauge, so that's not the problem, look at the sensor readings with diagnostics, on the diesel, typically, it's a number between 0 & 255, not an actual temperature reading (will depend on whose diagnostics are used) 255 equates to 0C; 0 equates to fecking hot. If you can see the sensor reading and monitor it as the temperature of the engine rises, that will prove the sensor. If the sensor responds correctly and the gauge responds correctly that leaves the BECM. My guess is still the sensor.
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BeCM has been swapped as well as two coolant sensors. There is only one possible part number for the sensor, and it was right both times. As far as the readings, when I plug diag. In I can watch coolant temp rise and lower. It was showing anywhere from 87-97 degreesC. Or maybe that was just a value? Either way...
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Another bump...at a complete loss here. The shop is on very good terms and local to Atlantic British, a major LR parts provider for the entire U.S. They spoke and AB's tech team was just as stumped as everyone else. This is most frustrating by the fact that other people seem to have this problem but a solution is yet unknown! As it is, I wont drive the car because I don't know what the temp is, so it has been sitting for almost 2 weeks!
StuckAgainSteve
Well-Known Member
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- London
! As it is, I wont drive the car because I don't know what the temp is, so it has been sitting for almost 2 weeks!
But it'd take you 15 minutes to slap a simple remove Maplins (Radio Shack) temperature gauge (with setable alarm) on the car until you sort the problem - they cost under $20.
No one has anything here local...would have be shipped. I will most likely be ordering one online and waiting a week or so for it to show up (which is why I normally refuse to shop online
)
TSC
New Member
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- 102
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- East Sussex
I am wondering as well having read the entire thing
