Outside temp 130 degrees!
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Registered User
Joined: Oct 2006
Posts: 4
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From: Kalamazoo, MI
Outside temp 130 degrees!
Can someone help me figure out what happened to my outside temp guage? It constantly reads 130 degrees. I've found the sensor, and tested the resistance per other posts on this site, and it seems fine. As soon as I turn the truck on, it reads 130 instantly. This has been going on for more than 2 weeks now, and it's always 130. If I turn the truck on with the sensor unplugged, it reads 95 for about 3 seconds, and then changes to 130. With the sensor plugged in, it just goes to 130.
Not sure if it's related, but I changed the EGR valve about 2 weeks ago as well. I reset the PCM by pulling the fuse (again, as learned on this site). I can't say if the temp problem started at that time or not, just roughly the same timing.
Any help would be greatly appreciated.
Thanks,
Tim
Not sure if it's related, but I changed the EGR valve about 2 weeks ago as well. I reset the PCM by pulling the fuse (again, as learned on this site). I can't say if the temp problem started at that time or not, just roughly the same timing.
Any help would be greatly appreciated.
Thanks,
Tim
Thread Starter
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Registered User
Joined: Oct 2006
Posts: 4
Likes: 0
From: Kalamazoo, MI
RE: Outside temp 130 degrees!
Unfortunately, not under warranty, it's an 04 with 42K miles.
I did check the sensor per another users post, and it appears to have the correct resistance for the proper temperature. I checked it in ice water, and in near boiling water, and the resistance seems to be in spec.
I did check the sensor per another users post, and it appears to have the correct resistance for the proper temperature. I checked it in ice water, and in near boiling water, and the resistance seems to be in spec.
DC Insider
Joined: Aug 2005
Posts: 2,681
Likes: 1
From: cedar falls, ia
RE: Outside temp 130 degrees!
well i dont know what year your truck is, but this should apply to 02-05. this is coming right out of my 2004 ram service manual cd that i copied from my auto class...i hope this works cuz this took forever to type out...i also included 3 wiring diagrams that hopefully will be of some help...if u need anything else, e-mail me at hemi3585@yahoo.com hope this all helps man
Diagnosing and Testing - Ambient Temp Sensor
(1) Turn Ign switch OFF, disconnect and isolate negative battery cable. Disconncent ambient temp sensor connector
(2) Measure resistence of temp sensor at 24 C (75 F), sensor resistance should be approx 10.3 kilohms. At 30 C (86 F) sensor resistance should be aprrox 7.57 kilohms. Resistance should decrease as temp increases. If OK, refer to Diagnosis and Testing - Ambient Temp Sensor Circuit. If not ok, replace sensor
[size=3]Diagnosis and Testing - Ambient Temp Sensor Circuit[/size]
(1) Turn Ign switch off, disconnect negative battery cable. Disconnect ambient temp sensor and Front Control Module connector
(2) Connect jumper wire between the two terminals of the harness side of the ambient temp sensor
(3) Check for continuity between the sensor return ciruit and the ambient temp sensor signal circuit cavities of the Front Control Module harness side connector. there should be continuity, if OK go to step 4. If not OK, repair the open sensor return or signal circuit.
(4) Remove jumper wire. Check for continuity between sensor return circuit cavity of FCM harness connector and a good ground. There should be no continuity. If OK, go to step 5. If not OK, repair shorted sensor return circuit.
(5) Check for continuity between ambient temp sensor signal cavity of the FCM harness connector and a good ground. There should be no continuity. If OK, refer to Diagnosis and Testing - Overhead Console. If not ok, repair shorted ambient temp sensor signal ciruit.
Diagnosis and Testing - Overhead Console
If problem with the overhead console is inaccurate or scrambled display, refer to Self Diagnostic Test.
(1) Remove overhead console from headliner
(2) Check battery voltage at the overhead console connector. Go to step 3 is OK, check for battery voltage in the Integrated Power Module at the appropriate fuse and repair open fused circuit as required.
(3) Turn Ign ON, check fused ign switch output circuit at the overhead console connector. If OK, go to step 4. If not OK, repari open or shorted circuit.
(4) Turn Ign OFF, disconnect negative battery cable. Check for continuity between the ground cavity of the overhead console connector and a good ground. There should be continuity. If OK, refer to Self Diagnostics. If not OK, repair the open ground circut as required.
Self Diagnostics
(1) With ignition switch in the OFF position, simultaneously depress and hold the STEP and RESET buttons.
(2) Turn Ign switch ON
(3) Folowing completion of the test, the electronics module will display one of the folloing messages:
a. Pass Self Test (EVIC only), Pass (CMTC)- the electronics module is working properly
b. Faild Self Test (EVIC only), FAIL (CMTC)- The electronics module has an internal failure. The module must be replaced.
c. Failed J1850 Communication (EVIC only), Bus (CMTC)- the electonics module is not receiving proper message input throught the J1850 PCI data bus curcuit. This can result from one or more fault electronic modules in the vehicle or from a faulty PCI data bus. the use of a DRBIII scan tool and proper diagnostic procedures manual are required for further diagnosis.
[IMG]local://upfiles/20353/CD4FCB7F45AC4ED39A98EB35AB86928F.jpg[/IMG]
[IMG]local://upfiles/20353/60CF8F9977C14964A7AE0702C78808B8.jpg[/IMG]
[IMG]local://upfiles/20353/F4D2DCCEFFAF45B5885C4A2221274244.jpg[/IMG]
Diagnosing and Testing - Ambient Temp Sensor
(1) Turn Ign switch OFF, disconnect and isolate negative battery cable. Disconncent ambient temp sensor connector
(2) Measure resistence of temp sensor at 24 C (75 F), sensor resistance should be approx 10.3 kilohms. At 30 C (86 F) sensor resistance should be aprrox 7.57 kilohms. Resistance should decrease as temp increases. If OK, refer to Diagnosis and Testing - Ambient Temp Sensor Circuit. If not ok, replace sensor
[size=3]Diagnosis and Testing - Ambient Temp Sensor Circuit[/size]
(1) Turn Ign switch off, disconnect negative battery cable. Disconnect ambient temp sensor and Front Control Module connector
(2) Connect jumper wire between the two terminals of the harness side of the ambient temp sensor
(3) Check for continuity between the sensor return ciruit and the ambient temp sensor signal circuit cavities of the Front Control Module harness side connector. there should be continuity, if OK go to step 4. If not OK, repair the open sensor return or signal circuit.
(4) Remove jumper wire. Check for continuity between sensor return circuit cavity of FCM harness connector and a good ground. There should be no continuity. If OK, go to step 5. If not OK, repair shorted sensor return circuit.
(5) Check for continuity between ambient temp sensor signal cavity of the FCM harness connector and a good ground. There should be no continuity. If OK, refer to Diagnosis and Testing - Overhead Console. If not ok, repair shorted ambient temp sensor signal ciruit.
Diagnosis and Testing - Overhead Console
If problem with the overhead console is inaccurate or scrambled display, refer to Self Diagnostic Test.
(1) Remove overhead console from headliner
(2) Check battery voltage at the overhead console connector. Go to step 3 is OK, check for battery voltage in the Integrated Power Module at the appropriate fuse and repair open fused circuit as required.
(3) Turn Ign ON, check fused ign switch output circuit at the overhead console connector. If OK, go to step 4. If not OK, repari open or shorted circuit.
(4) Turn Ign OFF, disconnect negative battery cable. Check for continuity between the ground cavity of the overhead console connector and a good ground. There should be continuity. If OK, refer to Self Diagnostics. If not OK, repair the open ground circut as required.
Self Diagnostics
(1) With ignition switch in the OFF position, simultaneously depress and hold the STEP and RESET buttons.
(2) Turn Ign switch ON
(3) Folowing completion of the test, the electronics module will display one of the folloing messages:
a. Pass Self Test (EVIC only), Pass (CMTC)- the electronics module is working properly
b. Faild Self Test (EVIC only), FAIL (CMTC)- The electronics module has an internal failure. The module must be replaced.
c. Failed J1850 Communication (EVIC only), Bus (CMTC)- the electonics module is not receiving proper message input throught the J1850 PCI data bus curcuit. This can result from one or more fault electronic modules in the vehicle or from a faulty PCI data bus. the use of a DRBIII scan tool and proper diagnostic procedures manual are required for further diagnosis.
[IMG]local://upfiles/20353/CD4FCB7F45AC4ED39A98EB35AB86928F.jpg[/IMG]
[IMG]local://upfiles/20353/60CF8F9977C14964A7AE0702C78808B8.jpg[/IMG]
[IMG]local://upfiles/20353/F4D2DCCEFFAF45B5885C4A2221274244.jpg[/IMG]
Professional
Joined: Feb 2005
Posts: 217
Likes: 0
From: Oak Forest IL
RE: Outside temp 130 degrees!
Wow, nice post IMO. Very considderate. Just a suggestion, if you have a local junk yard I bet they would part with a little sensor for very little dough from a wrecked ram. Good luck finding a totaled newer ram and unfortunatly 99% of all vehicles total out due to front end damage. Good luck anyways and worth a shot.