For 1990-2009 cars only
Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC C0550 32: Electronic Control Unit (ECU) Performance General Memory FailureDTC C0550 34: Electronic Control Unit (ECU) Performance RAM Failure
DTC C0550 35: Electronic Control Unit (ECU) Performance ROM Failure
DTC C0550 39: Electronic Control Unit (ECU) Performance Internal Electronic Failure
DTC C0550 4B: Electronic Control Unit (ECU) Performance Calibration Not Learned
Circuit/System Description
The internal fault detection is handled inside the power take-off (PTO) module. No external circuits are involved.
Conditions for Running the DTC
The PTO module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.
Conditions for Setting the DTC
The PTO module has detected an internal malfunction.
Action Taken When the DTC Sets
The PTO module refuses all additional inputs.
Conditions for Clearing the DTC
| • | A current DTC clears when the malfunction is no longer present. |
| • | A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction. |
Diagnostic Aids
| • | This DTC may be stored as a history DTC without affecting the operation of the module. |
| • | If stored only as a history DTC and not retrieved as a current DTC, do not replace the module. |
| • | If this DTC is retrieved as both a current and history DTC, replace the module that the DTC set for. |
Circuit/System Verification
Verify that the PTO module is programmed correctly. If this DTC still retrieved as current, replace the PTO module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for PTO module replacement, setup, and programming
