Description
This diagnostic applies to internal microprocessor integrity conditions within the powertrain control module (PCM) and the throttle actuator control (TAC) module. This diagnostic also addresses if the PCM is not programmed.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC P0601 Control Module Read Only Memory (ROM) |
| • | DTC P0602 Control Module Not Programmed |
| • | DTC P0604 Control Module Random Access Memory (RAM) |
| • | DTC P0606 Control Module Internal Performance |
| • | DTC P2610 Control Module Ignition Off Timer Performance |
Conditions for Running the DTC
DTC P0601
The following conditions must be met:
| • | The ignition switch is in Run or Crank. |
| • | System voltage is more than 5 volts. |
| • | Engine Speed parameter is less than 5,000 RPM. |
DTC P0602
The following conditions must be met:
| • | The ignition switch is in Run or Crank. |
| • | The controller is identified as a service replacement PCM. |
DTC P0604
The ignition switch is in Run or Crank.
DTC P0606
The following conditions must be met:
| • | The ignition switch is in Run or Crank. |
| • | During test function after key off before the control module powers down. |
DTC P2610
The following condition must be met:
| • | The ignition switch is in the OFF position for at least 1.6 seconds. |
| • | Low battery voltage or a battery disconnect condition has not taken place. Ignition OFF timer from the previous ignition cycle is stored. |
Conditions for Setting the DTC
DTC P0601
The PCM checksum value is incorrect for at least one sample. Each sample is 50 milliseconds. The PCM detects that the check sum value is incorrect for 0.05 second. This diagnostic runs continuous.
DTC P0602
The PCM has not been programmed with Key On and Engine Off for one sample. Each sample is 100 milliseconds. The PCM has not been programmed at Key On and Engine Off for 0.1 second. This diagnostic runs continuous.
DTC P0604
The PCM is unable to correctly write and read to and from random access memory (RAM) during the following conditions:
| • | Key up initialization for one count. Each count is a read and write sample. Each sample is 100 milliseconds. This portion runs one per ignition cycle. |
| • | Counter increments by 10 for each sample that does not correctly read and write to the RAM, and decrements by one for each correct sample. No more than 20 counts which do not read and or write correctly. Each read and write sample is 100 milliseconds. This portion runs continuously. |
| • | Counter increments by 10 for each sample that does not correctly read and write to the Desired Throttle Position RAM and decrements by one for each correct sample. No more than 20 counts which do not read and or write correctly. Each read and write sample is 12.5 milliseconds. This portion runs continuously. |
DTC P0606
The PCM detects that the Throttle Actuator Control (TAC) system has a process sequence error, clock error, or processor is not operating correctly. Each test runs in 18.5 milliseconds. DTC sets after 200 milliseconds that a fault is detected.
DTC P2610
This diagnostic has 2 tests that may set this DTC:
| • | The PCM detects the ignition off timer is less than 1 second. |
| • | The ignition is in the Off position for more than 8 seconds and the ignition off timer has not transitioned to Enable and/or the sample counter has not incremented. |
| • | This diagnostic runs continuous. |
Actions Taken When DTCs P0601, P0602, P0604, and P0606 Set
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
Actions Taken When DTC P2610 Set
| • | The control module illuminates the MIL on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
| • | If the diagnostic reports a failure, the control module uses a cold start model based on the engine coolant temperature and intake air temperature at engine start-up. Using the cold start model ensures that the control module is able to determine how much time has elapsed between ignition cycles. |
Conditions for Clearing the MIL/DTC P0601, P0602, P0604, P0606 and P2610
| • | The control module turns OFF the MIL after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||||
Is DTC P0602 set? | Go to Step 3 | Go to Step 5 | |||||||||
3 | Program the powertrain control module (PCM). Refer to Service Programming System (SPS) in Programming and Setup. Does DTC P0602 reset? | Go to Step 4 | Go to Step 7 | ||||||||
4 |
Does DTC P0602 reset? | Go to Step 5 | Go to Step 7 | ||||||||
5 | Test all voltage and ground circuits to the control module for the following:
Did you find and correct the condition? | Go to Step 7 | Go to Step 6 | ||||||||
6 | Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 6 | -- | ||||||||
7 | Start the engine. Did the DTC fail this ignition? | Go to Step 2 | Go to Step 8 | ||||||||
8 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
