Mechanics

CHEVY TEMPERATURE GAUGE DOES NOT WORK

2005 Chevrolet Silverado

Electrical problem
2005 Chevy Silverado V8 Four Wheel Drive Automatic 10,900 miles

With further investigation the none working gauge is linked with the " service engine soon" light.

First scenario: When the ignition switch is turned on and the " service engine soon" light comes on, the temperature gauge works but only for a short time.

Second scenario: When the ignition is turned on and the the " service engine soon" light does not come on the temperature gauge does not work at all.
Avatar
Claude Chevrier
December 11, 2008.



Ok first off have you had it scanned to see if there are any stored codes? If not check with you local parts stores and find one that will do a free scan as many parts stores do this. Get the codes if any and give them to me and I will look to see if any are linked to your problem. Otherwise we will need to check the body control module which controls the instrument cluster to see if it is working right. So first get me the codes and we will go from there. Thanks for your support and talk to you later.

Racefan966
Dec 12, 2008.
Hi, I finally got my hands on a code reader - here are my findings: Two codes came up
Primary code = P0118, engine coolant temperature circuit high input. Freeze frame date for this code =
Fuel system 1 = open load
Fuel slystem 2 = open load
Calculated load = 0.0%
Engine coolant temperature = -39 F.
STFT Bank 1 = 0.0%
LTFT Bank 1 = 5.4%
STFT Bank 2 = 0.0%
LTFT Bank 2 = 3.1%
Intake manifold pressure = 28.0 in. Hg.
Engine r.P.M. = 000 r.P.M.
Vehicle speed = 0 mph
Ignition timing = 0.0 degrees
Intake air temperature = 66 F.
Mass air flow sensro = 0.00 lb/min
Throttle position = 18.4%

Secondary code = P0116 - Temperature circuit range/performance. This code comes up as a " pending code".

Another point that might be worth noting: When I initially plugged in the code reader the first code came up as a " Red LED" code
After I disconnected the reader and reconnected the code came up as a " yellow LED" code - not sure if this is normal as I have never used a code reader before!

Another interesting finding - after I noticed my electrical problem I was scrolling through my instrument cluster data information which includes odometer, oil life, trip meters etc. My total engine hour meter has defaulted back to zero hours - looks like the computer has lost some memory? All other data is as per what it should be. Hope this information helps determine what my problem is. Thanks and look forward to your reply. Claude

Tiny
Claude Chevrier
Dec 18, 2008.
Ok first off the P0118 seems to be that the coolant temp sensor is telling the computer that the engine temp is -36 deg. So it is telling the computer to run extra fuel so this would make it run bad and get bad gas mileage. It seems to be that the P0116 code is backing this up. So I would replace the coolant temp sensor (not the sender) this should take care of this code make sure to clear the codes too other wise the computer will thing it is still a problem.
Is this scanner capable of scanning the BCM? If so then scan the BCM (body control module) for codes this will lead us to the instrument cluster problem. Get back to me with what you find out and we will take it from there.

Racefan966
Dec 19, 2008.
Hi Bob and Ken
I think it may be premature to start replacing sensors at this point as there is some information that has not been communicated properly to you. It would be considerable easier to call you by phone - is this possible? If so, send me your number and I will call you. If not, here is some of the information I gave you that has not been answered which I believe could be key to the problem.

The temperature gauge works fine when the service light goes on when the ignition switch is turned on - but only works for a short period of time. Please comment/explain this.

The temperature gauge does not work at all when the service light does not turn on when the ignition switch is turn on. Please comment/explain this.

Why is the service light not going on everytime the ignition switch is turned on - the owners manual says it should - please comment/explain this.

This leads me to believe the temperature gauge is not the root problem but the fact that the service light is not activated when the ignition switch is turned on is the root problem. Please comment.

My understanding for the " Freeze frame Data" is what/where the engine condition was when the code originated - if this is true, the engine coolant temperature of -39 F. Means simply the temperature of the coolant when the code occurred - yes it is cold in this country! This is further confirmed by the rest of the freeze frame information - ie engine rpm at zero and vehicle speed at zero. Please comment.

Can you explain why the engine hour meter has defaulted back to zero hours? Please comment.

One other piece of information that may be helpful. After I noticed my temperature gauge not working it was noticed that a mouse or mice had got inbetween the engine and firewall ( directly in the middle of firewall or directly behind the intake manifold) and chewed up some of the insulation. I spent a couple hours cleaning up their mess and looked very close for a chewed wire - nothing was noticed but I certainly could have missed something hiding in that area. Is there electrical wires in that area that would be connected to the " engine service light/hour meter clock/temperture gauge that could be the reason for all of the above? Please comment. Thanks in advance for your time and patience on this matter. Look forward to your reply or phone number. Cheers Claude

Tiny
Claude Chevrier
Dec 19, 2008.
Ok then if you feel you should not replace the sensor the do me a favor do an ohm test on the sensor at a known temp and give that info, unplug the sensor and ohm across the terminals on the sensor. As for the code and the info from that code leads me to believe this code is causing running problems. It is cold were I live too but even with the wind chill it never got to -39, and if the computer thinks this is true you truck will run rich and won't start right.
As for you dash unit (your gauge) I feel we need to look at the BCM (Body Control Module) as this controls all this and more. See a BCM controls the instrument cluster and interior lighting and so on.
Now you said a mouse got into you insulation and such you need to look closer around the ECM (Engine Control Module- ie computer) and look for any wires that have been chewed through if there are you need to fix them and look really close to the ground wires. You also need to look at your multi function (headlight and turn) switch closely too.
The cluster is controled buy your multi function switch and the BCM together. Look under the dash just below the steering column as this is where the BCM is located. Check all the plug ins and make sure it is all secure. Let me know what you find out.

Racefan966
Dec 20, 2008.