High Engine Oil Temp Warning
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 19
Likes: 0
High Engine Oil Temp Warning
Hello, I am posting a new thread because the old one got off on my other problems, which helped me.
This problem I cant seem to solve. Here is what I know:
2001 Corvette
High Engine oil temp warning on display: 352 deg.
Remove sensor wire from sensor 352 deg.
ground sensor singal wire display then reads 392 deg
open connector C102 at battery, signal wire has 3.3 Volts
sensor circuit has 333 ohms
Codes
c1232 b1001 b2262 b2264
It would probably set code B1542 if I drove it.
remove fuse 19 IPC warning message still displayed but temp displays 0 deg.
with harness disconnected near battery dic warning and temp 352 deg.
signal wire voltage at harness connection at battery: 3.1 volts
With key off 337 ohlm on signal wire to ground
Thanks for your help
This problem I cant seem to solve. Here is what I know:
2001 Corvette
High Engine oil temp warning on display: 352 deg.
Remove sensor wire from sensor 352 deg.
ground sensor singal wire display then reads 392 deg
open connector C102 at battery, signal wire has 3.3 Volts
sensor circuit has 333 ohms
Codes
c1232 b1001 b2262 b2264
It would probably set code B1542 if I drove it.
remove fuse 19 IPC warning message still displayed but temp displays 0 deg.
with harness disconnected near battery dic warning and temp 352 deg.
signal wire voltage at harness connection at battery: 3.1 volts
With key off 337 ohlm on signal wire to ground
Thanks for your help
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 19
Likes: 0
Maybe programming
I have been told by a vendor of PCM modules that my problem could be due to a configuration error. Maybe the BCM has been replaced on the car and is not programmed right. I am going to the local dealer Monday to see if his TECH2 will help with the situation, if he can resolve the configuration error I am hoping it will solve the temperature problem as well as air bag light. Comments appreciated.
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,141
From: Dyer, IN
I have been told by a vendor of PCM modules that my problem could be due to a configuration error. Maybe the BCM has been replaced on the car and is not programmed right. I am going to the local dealer Monday to see if his TECH2 will help with the situation, if he can resolve the configuration error I am hoping it will solve the temperature problem as well as air bag light. Comments appreciated.
The oil temperature is a discrete circuit (wiring is direct between the IPC and sensor) .....no PCM....no BCM.
My initial concern is the low voltage at C102. You should read 4.5 - 5 volts on the dark green wire/white stripe. You also did not mention if you had a good ground at the black wire of C102. Curious to know if you can measure any voltage on the black wire at C102?
Since you have a voltage drop, and a max temp indication, the 5 volt line is shorting somewhere.
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,141
From: Dyer, IN
Drifting
Joined: Jul 2005
Posts: 1,484
Likes: 27
From: Torrance Calif
Should be less then 50 mv with the air conditioning and lighting on, engine running.
Vettes are notorious for bad grounding.
Last edited by heavymetals; Oct 1, 2011 at 12:45 AM.
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,141
From: Dyer, IN
Seems to me you're not familiar with the system. With C102 disconnected, the sensor wiring is completely out of the equation, which leaves the wiring from harness side of C102 to the IPC. So if C102 is disconnected, and the temperature is still reading at max, a bad ground is NOT the issue.
Drifting
Joined: Jul 2005
Posts: 1,484
Likes: 27
From: Torrance Calif
I thought he said it was reading a high temp, not pegged (no ground).
The primary ground connection from the battery to the "frame" can have a junction drop that causes a negative offset that gets added to the temp sensor.
I have seen it go as high as 400+ mv.
OP does not say what he is using for negative reference, frame or battery.
That is what makes the 3.3 volt reading suspect.
Sensor B+ should be about 4.8v.
Maybe lost continuity of the ground connection at the sensor end, because grounding of the sensor input should give no temp reading.
Even thought the sensor connects directly to the IPC, it still has to have a good ground , the sensor connection at the IPC could have a bad ground or the IPC itself.
The primary ground connection from the battery to the "frame" can have a junction drop that causes a negative offset that gets added to the temp sensor.
I have seen it go as high as 400+ mv.
OP does not say what he is using for negative reference, frame or battery.
That is what makes the 3.3 volt reading suspect.
Sensor B+ should be about 4.8v.
Maybe lost continuity of the ground connection at the sensor end, because grounding of the sensor input should give no temp reading.
Even thought the sensor connects directly to the IPC, it still has to have a good ground , the sensor connection at the IPC could have a bad ground or the IPC itself.
Last edited by heavymetals; Oct 1, 2011 at 01:15 AM.
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Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 19
Likes: 0
More Info
Voltage at Batt ign. off 12.42
Batt to Frame/engine 12.42
Ignition on, fan running motor off, 3.3 volts at sender circuit c102
ground wire has 71mv between it and frame.
The high temp warning is displayed even when the temp reading is below where it is supposed to come on. (375?)
It is warning even when fuse 19 is pulled and temp is o.
Thats what makes me think its in a module.
Thanks for all your comments, I appreciate it.
Batt to Frame/engine 12.42
Ignition on, fan running motor off, 3.3 volts at sender circuit c102
ground wire has 71mv between it and frame.
The high temp warning is displayed even when the temp reading is below where it is supposed to come on. (375?)
It is warning even when fuse 19 is pulled and temp is o.
Thats what makes me think its in a module.
Thanks for all your comments, I appreciate it.
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 19
Likes: 0
Fuse 19
I will pull fuse 19 again and verify the outcome, cant remember for sure. Pulled fuse 19 again, the temp. is blank, but the DIC still warns of high engine oil temp, reduce RPM.
Last edited by farmdog; Oct 1, 2011 at 10:00 AM. Reason: added info
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,141
From: Dyer, IN
I thought he said it was reading a high temp, not pegged (no ground).
The primary ground connection from the battery to the "frame" can have a junction drop that causes a negative offset that gets added to the temp sensor.
I have seen it go as high as 400+ mv.
OP does not say what he is using for negative reference, frame or battery.
That is what makes the 3.3 volt reading suspect.
Sensor B+ should be about 4.8v.
Maybe lost continuity of the ground connection at the sensor end, because grounding of the sensor input should give no temp reading.
Even thought the sensor connects directly to the IPC, it still has to have a good ground , the sensor connection at the IPC could have a bad ground or the IPC itself.
The primary ground connection from the battery to the "frame" can have a junction drop that causes a negative offset that gets added to the temp sensor.
I have seen it go as high as 400+ mv.
OP does not say what he is using for negative reference, frame or battery.
That is what makes the 3.3 volt reading suspect.
Sensor B+ should be about 4.8v.
Maybe lost continuity of the ground connection at the sensor end, because grounding of the sensor input should give no temp reading.
Even thought the sensor connects directly to the IPC, it still has to have a good ground , the sensor connection at the IPC could have a bad ground or the IPC itself.
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,141
From: Dyer, IN
Drifting
Joined: Jul 2005
Posts: 1,484
Likes: 27
From: Torrance Calif
Safety Car
Joined: Sep 2002
Posts: 4,030
Likes: 6
From: Maryland
I'm no expert but I have heard others have tuned out the codes for engine & emission related problems. I'd say yes--I doubt if the Diablo could but a tuner such as ECS could if you sent them your PCM.
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 19
Likes: 0
Dealer tried
Chevy dealer resolved configuration error, and air bag light went out.
He had trouble, and I think the tech had limited knowledge of the system.
I put 12V+ to the signal wire going to the Instrument Cluster, It lowered the engine temp, to 275. The display does not say " high engine oil temp". It displays the erroneous temp. So far no smoke or smell.
He had trouble, and I think the tech had limited knowledge of the system.
I put 12V+ to the signal wire going to the Instrument Cluster, It lowered the engine temp, to 275. The display does not say " high engine oil temp". It displays the erroneous temp. So far no smoke or smell.
Thread Starter
Heel & Toe
Joined: Sep 2011
Posts: 19
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New (used) Cluster fixed it- Can Odometer be changed
I bought a used instrument cluster and that solved the problem, but now I have 120000 miles on the odometer instead of 80K. My dealer says I will have to remove it and send it in to correct the problem. Any advise appreciated.
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,141
From: Dyer, IN
You can swap the circuit board that contains the mileage info to the new cluster. Technically it's not "legal", but it least the mileage will be accurate.
Tech Contributor
Joined: Jan 2007
Posts: 19,401
Likes: 1,141
From: Dyer, IN