SS Different Day
Thread Starter
Racer
Joined: Sep 2007
Posts: 393
Likes: 0
From: Bartonville Illinois
SS Different Day
Here's the problem. 1993 coupe, DTC15 engine too cool. SES comes on about 5 seconds after start, fans both run at this same instant.
"NEW" wires to sensor, "NEW" sensor. Digital dash reading perfectly normal, reads ambient in garage when cool and gradually runs up to about 194-205 while driving.
I had "Three" different ECM's in the car and they all did the same thing.
I had one ECM that had a loose component and some of the clear coating was gone so I sent it to Cardone for a Reman. Got it back today and it did the same as before. 4 ECM's and same problem.
The car runs fine, its just that the fans run all the time and the SES light stays on.
Has anyone ever had trouble with their CCM and had it replaced because of communication problems? I can go through the CCM diags and they seem to work fine. Turn on outputs and toggle inputs fine, it sets codes and they can be erased.
I have a spare CCM, the problems is that it has about 25,000 more miles registered it it than my car, and of course the VIN is not the same and the VATS is different.
Can the mileage and VIN and VATS be changed by a dealer on a used CCM?
Thanks ahead.
"NEW" wires to sensor, "NEW" sensor. Digital dash reading perfectly normal, reads ambient in garage when cool and gradually runs up to about 194-205 while driving.
I had "Three" different ECM's in the car and they all did the same thing.
I had one ECM that had a loose component and some of the clear coating was gone so I sent it to Cardone for a Reman. Got it back today and it did the same as before. 4 ECM's and same problem.
The car runs fine, its just that the fans run all the time and the SES light stays on.
Has anyone ever had trouble with their CCM and had it replaced because of communication problems? I can go through the CCM diags and they seem to work fine. Turn on outputs and toggle inputs fine, it sets codes and they can be erased.
I have a spare CCM, the problems is that it has about 25,000 more miles registered it it than my car, and of course the VIN is not the same and the VATS is different.
Can the mileage and VIN and VATS be changed by a dealer on a used CCM?
Thanks ahead.
Le Mans Master
Joined: Dec 2004
Posts: 5,789
Likes: 8
From: Myrtle Beach SC
St. Jude Donor '05-'06
Not after it has 100mi on it.Sorry to hear you still chasing this down.Did you happen to check the IAT it is another temp sensor? Just trying to think outside the box as I know you have checked everything under the sun.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
Do you have a scan tool that will display the sensor value rather than going by the cluster display? You said you replaced the sensor and wiring, how about the connectors at the sensor and ECM? I would check the sensor resistance at pins A13 and B18 at the ECM, good luck.
Thread Starter
Racer
Joined: Sep 2007
Posts: 393
Likes: 0
From: Bartonville Illinois
Do you have a scan tool that will display the sensor value rather than going by the cluster display? You said you replaced the sensor and wiring, how about the connectors at the sensor and ECM? I would check the sensor resistance at pins A13 and B18 at the ECM, good luck.
I have a paralell jumper wired into the harness that I can watch the voltage while I drive the car. I run the cable into the car to DVM and I can run Datamaster at the same time.
Datamaster shows temps almost exactly what the dash is reading, I would expect this since DM is displaying ECM info. Digital meter is displaying voltage at the proper level.
From a cold start condition the car needs probably at least 5 to ten minutes to warm up and then set this alarm if it does not reach temp.
This sets the alarm right away. Even if the sensor was gone the car should at least take a few minutes to decide to set the alarm. The alarm is "Running too cool". If it were "Overtemp" it would set the alarm immediately.
I also check temp with a Mr gasket radiator cap and use an infared thermometer.
I also paid to have it scanned with a GM service tool and it reported no problems with coolant system.
Safety Car
Joined: Jun 2006
Posts: 3,629
Likes: 28
From: FL
I have a paralell jumper wired into the harness that I can watch the voltage while I drive the car. I run the cable into the car to DVM and I can run Datamaster at the same time.
Datamaster shows temps almost exactly what the dash is reading, I would expect this since DM is displaying ECM info. Digital meter is displaying voltage at the proper level.
From a cold start condition the car needs probably at least 5 to ten minutes to warm up and then set this alarm if it does not reach temp.
This sets the alarm right away. Even if the sensor was gone the carshould at least take a few minutes to decide to set the alarm. The alarm is "Running too cool". If it were "Overtemp" it would set the alarm immediately.
I also check temp with a Mr gasket radiator cap and use an infared thermometer.
I also paid to have it scanned with a GM service tool and it reported no problems with coolant system.
I understand how frustrating this must be but for the record I was not questioning your diagnosis to this point, just hoping I might be able to help, the good luck wishes are sincere.
I am still confused by one thing, your first post seemed to indicate the SES light came on immediately at start up, this one says 5 to 10 minutes?
