Question about 2006 Pontiac Grand Prix

1 Answer

06 grand prix --my temp gauge is not working, the needle is flatlined. when i start the car the needle swings to the top but then buries itself at the bottom of the gauge. On my dash i have digital read that shows the temp outside. the digital info is not relaying the temp outside like it usually does, it is 75 outside and the guage says 95 when i am stopped and if i go down the highway or something it will drop down over 10 or 20 degrees. so it is not registering the actual outside temp like it normally does. Coincidence or a related issue. Also i took my vehicle in for service today and got an oil change, about 2 hours later i noticed the gauge issue. What is going on? is it just electrical or a fuse? can i still drive with out consequence or am i going to overheat the vehicle. So is it just a coincidence that someone was under my hood today or did they mess up my vehicle. Any advice is appreciated. thanks

Posted by cwalter512 on


1 Answer

Duane Wong

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Pontiac Master
  • 6,826 Answers

Coolant Temperature Sensor I would take the vehicle back to where it was serviced and try to ask them about what may have gone wrong to cause this problem.
The Intake Air Temperature sensor should also be checked.

The following is the procedure for servicing the coolant temperature sensor: Removal & Installation 3.8L Engine To Remove:

  1. Drain the coolant.
  2. Disconnect the engine coolant temperature (ECT) sensor connector. ECT sensor 3.8L 06 grand prix --my temp gauge is not working, the - gm-04-38-4321.gif

  3. Remove the ECT sensor.
To Install:
  1. Apply thread sealer P/N 12346004 or equivalent to the engine coolant temperature (ECT) sensor threads.
  2. Install the ECT sensor. Tighten 18 ft-lb (25 Nm).
  3. Connect the ECT sensor harness connector.
  4. Fill the cooling system.
5.3L Engine To Remove:
  1. Drain the coolant below the level of the engine coolant temperature (ECT) sensor.
  2. Disconnect the ECT sensor electrical connector. ECT sensor 5.3L

  3. Remove the ECT sensor from the cylinder head.
To Install:
  1. Clean the threads in the sensor mounting hole.
  2. Apply sealer P/N 13246004 or equivalent to the threads of the sensor.
  3. Install the sensor and tighten 15 ft-lb (20 Nm).
  4. Connect the ECT sensor electrical connector.
  5. Fill the cooling system and check for leaks.

Posted on Sep 25, 2010

  • cwalter512 Sep 25, 2010

    so do u think it is safe to drive or will it overheat and crack my head or something

  • Duane Wong
    Duane Wong Sep 25, 2010

    I would check the temperature of the coolant with a thermometer and make sure it doesn't overflow in the overflow tank or boil over.

    If the engine doesn't malfunction, and the reading is just false, then the vehicle can be driven.

    But, I would not allow the problem to continue if it were my car, because I like to have accurate instrumentation.

    Take the car back to where it was last serviced and describe your problem. I would hope that they would support problems that arise after servicing your vehicle.



Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Will the temperature sending unit make my 2000 pontiac grand prix shut off

Don't think so... I had one 2004 prix that lost it's coolant and it ran until it destroyed itself... Had another that would hit red on temp during the summer in the desert mountains. Never shut down on me though.... replaced the radiator, water pump and thermostat. My fans kick on about 3/4 of the temp gauge. Normal temp is between 1/2 & 3/4.

Jun 24, 2014 | 2004 Pontiac Grand Prix

1 Answer

Temp gauge not registering and cooling fan's run continuously

the temp gauge works of a different sender to the coolant sensor. IT has 1 wire only and changes resistance as the water heats up there by moving the needle on the gauge up the scale Check that the wire is tight on the sender unit and if so then replace the sender unit.. The difficulty in re starting the motor may be because it is over heating but you would not know this because of the faulty sender unit.

Jan 09, 2014 | 2005 Pontiac Grand Prix

2 Answers

I had my 2006 grand prix fix 3 times for the tempature gage and stilss the gage goes over the 3 line

I think you should start thinking it might not be the gage itself but >Problem with the wires in the circuit itself Also warm car up take a thermometer & check coolant tempature cross referance with temp gauge in the car

Jun 16, 2011 | 2006 Pontiac Grand Prix

1 Answer

Hello i have a 2006 pontiac grand prix and the temp guage just flatlined

check the temp sending unit to make sure the wire is connected. if so then replace the sending unit. hope this helps

Feb 01, 2011 | 2006 Pontiac Grand Prix

1 Answer

I noticed my engine light on the dash of my 2004 Grand Prix was on so checked code with tester. Said coolant temp below thermostat temp. Replaced thermostat drove car for 30 minutes. Popped hood fixed top...

Yes that is what the code means. GM usually uses two, one that makes the gauge work and one that tells the ECM what the engine temp. is. You need the one for the computer.

Jan 20, 2011 | 2004 Pontiac Grand Prix

1 Answer

Temp gauge does not work I think it is not connected but not sure. Where and how does it connect to the engine

Its connected by 1 wire to the engine block, it looks like a bolt head with a spade connector coming out of it, probably copper or brass coloured, about a 12mm nut. There should be a wire going to it - if you short this wire to the car body/engine the temp will either bury itself at HOT or COLD depending on how the guage works - if you can make the needle move by shorting the temp lead on the engine then it's the temp sensor at fault and not the wiring, conversely if the temp gauge doesn't budge at all when you do this the gauge is faulty or the wire is broken somewhere.

Jan 26, 2010 | 1984 Chevrolet Blazer

4 Answers

The temperature gauge on my 2002 grand prix dose

the temperature sending unit on a 97 grand prix 3800 gt(which is also the coolant temperature sensor) is not accurate. the sending unit part of this sensor only sends info to the guage on the dash. the coolant sensor part sends info to the computer of the car. it is located under thermostat and somewhat difficult to get at. i had put a brand new one in and my temperature on my dash is all over the place---even with good thermostat and properly bled system. when i hook up a scanner to my computer, the coolant sensor is sending the computer(ecu??) what seems to be the right temp. anywhere from 194 degrees to 217 when hot. the guage however on dash go from 160 to 260 in less than 2 minutes.

Nov 16, 2009 | 2002 Pontiac Grand Prix

1 Answer

Heat fluctuation on temp gauge

change the sending unit to the fan, if that doesnt work check for power too the fan or even a bad fan

Mar 22, 2009 | 1995 Pontiac Grand Prix

1 Answer

Needle in the temp gauge moves up and down

have you been adding coolant ? if the level is low you can experience this problem , or it could be a thermostat thats getting to the end of it's life !

Feb 06, 2009 | 1999 Pontiac Grand Prix

Not finding what you are looking for?
2006 Pontiac Grand Prix Logo

3,151 people viewed this question

Ask a Question

Usually answered in minutes!

Top Pontiac Experts


Level 3 Expert

85239 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22485 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8984 Answers

Are you a Pontiac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides