temp readout on 2001 C5
#1
temp readout on 2001 C5
I have a 2001 corvette when i turn ignition to (do not start engine) on the instrument information center reads ambient temp when I start engine the temp gauge pegs 260 deg and info center reads xxx. If i disconnect the temperature sensor wire and turn ignition to on the information center reads ambient temp when I start the engine the temp gauge pegs and info center reads xxx. I have grounded the temp sensor in block located on driver side behind alternator with no effect. I have not read the voltage on the two wires going to temp sensor. My question is there another sensor? I was told no. Could it be the ECM is sending wrong voltage? What ideas does anyone have? The check engine light does come on but I assume due to high temp I will get the codes read but it is still a mystery. Thought wires maybe damaged but it does read correct with ignition on engine off. Any help would be greatly appreciated. Thanks for Reading.
#2
I have a 2001 corvette when i turn ignition to (do not start engine) on the instrument information center reads ambient temp when I start engine the temp gauge pegs 260 deg and info center reads xxx. If i disconnect the temperature sensor wire and turn ignition to on the information center reads ambient temp when I start the engine the temp gauge pegs and info center reads xxx. I have grounded the temp sensor in block located on driver side behind alternator with no effect. I have not read the voltage on the two wires going to temp sensor. My question is there another sensor? I was told no. Could it be the ECM is sending wrong voltage? What ideas does anyone have? The check engine light does come on but I assume due to high temp I will get the codes read but it is still a mystery. Thought wires maybe damaged but it does read correct with ignition on engine off. Any help would be greatly appreciated. Thanks for Reading.
#3
c5
replaced the temp sensor located on left side of car behind the alternator. Ordered a nice code reader from ebay will read codes with it when it arrives this week. It does the same whether it is 17 degrees outside or 90. When ignition is on but engine not running both guage and info center on dash read correct ambient temp only when you start engine does it go to 260. Thanks for input
#4
Le Mans Master
You can pull the codes directly from the car without a scanner. It actually pulls codes from more systems than many scanners do.
See the instructions and linked video for how to do it.
Good luck.
See the instructions and linked video for how to do it.
Good luck.
When you have issues, always pull your DIC codes to see if they show anything. That is where you start. If you don't know how here is some help via a video and write up.
Retreiving & Clearing Codes on a 1997-2004 C5 Corvette - YouTube
READING YOUR C5 Engine Diagnostic Trouble Codes (DTC)
This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.
The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.
Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.
If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.
NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.
WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.
These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs
Here are some very good sites that explain what DTC mean:
http://www.gearchatter.com/viewtopic11755.php
http://www.obd-codes.com/trouble_cod...d-ii-codes.php
Make sure to include the H or C suffix when you post your DTCs!!
NOTE!!! Start the car and let it idle. Then take it for a drive and cause the problem to occur. When you return home pull the codes BEFORE you shut off the engine.
Do NOT discount the codes with the H following them. They can provide an audit trail for issues going on with the car. They ARE important in diagnosing problems.
Post ALL the codes that you pull with the engine running..........
Some codes go away WITHOUT setting an H code when you shut the engine off. I suspect you will have several codes that will show C or HC that do NOT show when the engine is turned off.
Retreiving & Clearing Codes on a 1997-2004 C5 Corvette - YouTube
READING YOUR C5 Engine Diagnostic Trouble Codes (DTC)
This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.
The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.
Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.
If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.
NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.
WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.
These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs
Here are some very good sites that explain what DTC mean:
http://www.gearchatter.com/viewtopic11755.php
http://www.obd-codes.com/trouble_cod...d-ii-codes.php
Make sure to include the H or C suffix when you post your DTCs!!
NOTE!!! Start the car and let it idle. Then take it for a drive and cause the problem to occur. When you return home pull the codes BEFORE you shut off the engine.
Do NOT discount the codes with the H following them. They can provide an audit trail for issues going on with the car. They ARE important in diagnosing problems.
Post ALL the codes that you pull with the engine running..........
Some codes go away WITHOUT setting an H code when you shut the engine off. I suspect you will have several codes that will show C or HC that do NOT show when the engine is turned off.
Last edited by QCVette; 01-20-2015 at 02:08 PM.
#5
Thanks, that is awesome did not know you could do that. Will try it out this weekend. Thanks so much....checked out service manual on Ebay over $300 guess it would eventually pay for itself....
#6
Le Mans Master
The onboard system will pull all the over 300 codes that can come from all modules in the car. Normal scanners will only show emissions related codes. Sorry you bought the scanner for no reason. Maybe you can use it on other cars.
#7
Drifting
Post a wtb in the for sale section. They can be had much cheaper than that from people who have sold their car.
#9
Drifting
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St. Jude Donor '14
You will have a p1114 and/or a p1258 stored. Either your yellow ect signal wire is shorted to ground or the ECM is bad. Disconnect the battery. Unplug the ect sensor and ECM connectors and test resistance from the yellow wire to ground. If you have continuity, the wire is shorted. If not the ECM is bad. My bet is the wire is shorted.
With everything but ect sensor connected, key on engine off coolant should read -40f.
With everything but ect sensor connected, key on engine off coolant should read -40f.
#10
Thanks i'll try it the stored active code was P0118 via the onboard computer. When I reset it while driving or engine off it resets and the temp guage and info center on the dash read correct temp. The reset lasts about 20-25 seconds then the heat/ac fan in the car drops a few rpm's then returns to normal while the temp guage returns to 260 deg F and the info center on dash reads xxx. I while try what you suggested and report back....thanks again for the help
#11
Tech Contributor
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Location: Anthony TX
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
When the ignition is ON,, the other wire should read 5 VDC reference voltage. See if it reads 5 VDC when it shows the problem. Maybe reference wire is shorted to another wire.
Reading it with a DC Volt Meter will tell you if the reff voltage is good before and after engine start.
Ive seen other sensors that are on the 5 VDC Reff circuit have issues and cause weird problems like you are experiencing.
Bill
Reading it with a DC Volt Meter will tell you if the reff voltage is good before and after engine start.
Ive seen other sensors that are on the 5 VDC Reff circuit have issues and cause weird problems like you are experiencing.
Bill
#12
Sorry to get back late but wanted to post an update. Had a few other projects get in the way. I checked for 5 VDC on the yellow & black wire going to temp sensor, nothing. I started to pull the cover on the ECM under the car next to passenger door. Saw that the access cover had been damaged and had yellow paint on it. When I removed the cover the ECM had the wire harness plastic cover broken in pieces. I also found three wires completely cut and hanging. White, black, & yellow wire. I was able to soldier the wires back together and covered in heat shrink. Fired car up and temp sensor works like it should. I still need to replace plastic harness cover and access panel. Looks like previous owner ran over a yellow curb and damaged the ECM wiring. If you ask me a **** poor place for the cars ECM, most cars it is located inside out of the weather. Again sorry for late update but thanks for all the help and on to the next problem...heads up display
Last edited by brehm1; 08-07-2016 at 09:59 PM.
#13
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CI 6,7,8,9,11 Vet
St. Jude Donor '08
Great job on the EXPLORATION & REPAIR!!,,
If you need great used parts, contact VETTENUTS
Bill
If you need great used parts, contact VETTENUTS
Bill