TCU Compatibility
Posted: Tue Oct 23, 2018 9:02 pm
This is an update to my previous thread, "A long sad tale, etc."
I solved the problem by replacing the TCU (from a '94 with one from a '90.
While this solved all performance problems and got rid of the original TCU error code (14 - Shift Solenoid #2), it added a new wrinkle.
I have been getting intermittent TCU error codes 22 - Atmospheric Sensor (or Barometric pressure).
Turns out that the '90-'92 ECUs had an atmospheric sensor in them and told the TCU what the pressure was. '93 and later did not have this in the ECU. So now, I have a '94 ECU which doesn't have a sensor and can't tell the TCU what the pressure is and a '90 TCU which expects the ECU to tell it what the Barometric pressure is. When that input is not there (and it never will be), the TCU throws code 22. I have no information about TCU internals so I have no idea why the code is intermittent.
I've sent the bad TCUs off for repair but until I match the ECU to the TCU, this situation will exist.
Hopefully, this information will save someone some time and/or trouble at some point.
I solved the problem by replacing the TCU (from a '94 with one from a '90.
While this solved all performance problems and got rid of the original TCU error code (14 - Shift Solenoid #2), it added a new wrinkle.
I have been getting intermittent TCU error codes 22 - Atmospheric Sensor (or Barometric pressure).
Turns out that the '90-'92 ECUs had an atmospheric sensor in them and told the TCU what the pressure was. '93 and later did not have this in the ECU. So now, I have a '94 ECU which doesn't have a sensor and can't tell the TCU what the pressure is and a '90 TCU which expects the ECU to tell it what the Barometric pressure is. When that input is not there (and it never will be), the TCU throws code 22. I have no information about TCU internals so I have no idea why the code is intermittent.
I've sent the bad TCUs off for repair but until I match the ECU to the TCU, this situation will exist.
Hopefully, this information will save someone some time and/or trouble at some point.