For 1990-2009 cars

## DTC P0603 Non-Europe or N. American Emissions

### Circuit Description

A normal function of the transmission control module (TCM) programming is to perform an internal check that verifies the integrity of the keep alive memory (KAM) memory allocations.

DTC P0603 sets when the KAM is not operating correctly when checked on initialization.

An area of KAM is failed a read/write test.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0603 Transmission Control Module (TCM) Long Term Memory Reset

### Conditions for Setting the DTC

• | The checksum of the current regulator data will be tested. If the checksum is not OK, then the error bit will be set.

• | If writing to FLASH during power latch phase failed

• | Each of the flash blocks has its own status which is located at the beginning of the each flash block and the status of the FLASH blocks do not fit together.

• | System voltage is too high or too low.

• | Transaxle input voltage is too high or too low.

• | Immediately after the above condition occurs

### Action Taken When the DTC Sets

• | The hold lamp will blink.

• | The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.

• | Adopt Emergency/Substitute mode and constant 4th gear by hydraulic control.

• | After ignition OFF/ON : 3rd gear by hydraulic control. P, R and N also possible.

• | Power supply cut off to the pressure control solenoid (PCS) valve.

### Conditions for Clearing the Hold Lamp/DTC

• | The hold lamp will turn OFF when the malfunction has not occurred after 3 ignition cycles.

• | A history DTC will clear after 40 consecutive warm-up cycles without a fault.

• | Using a scan tool can clear history DTCs.

### Diagnostic Aids

When DTC P0603 sets, the possible cause of fault could be TCM.

#### DTC P0603

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.

Does the scan tool display P0603?

Go to Step 3

Go to Diagnostic Aids

3 |

1. Turn the ignition OFF.
2. Replace the transmission control module (TCM). Refer to Transmission Control Module Replacement .

Is the replacement complete?

Go to Step 4

--

4 |

1. Using the scan tool, clear the DTCs.
2. Road test the vehicle within the Conditions for Setting this DTC, as specified in the text.

Does the scan tool indicate that this diagnostic has run and passed?

Go to Step 5

Go to Step 2

5 | Inspect if any DTCs are set. Are any DTCs displayed that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK

## DTC P0603 European and N.American Emissions

### Circuit Description

A normal function of the transmission control module (TCM) programming is to perform an internal check that verifies the integrity of the keep alive memory (KAM) memory allocations.

DTC P0603 sets when the KAM is not operating correctly when checked on initialization.

An area of KAM is failed a read/write test.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0603 Transmission Control Module (TCM) Long Term Memory Reset

### Conditions for Setting the DTC

• | The checksum of the current regulator data will be tested. If the checksum is not OK, then the error bit will be set.

• | If writing to FLASH during power latch phase failed

• | Each of the flash blocks has its own status which is located at the beginning of the each flash block and the status of the FLASH blocks do not fit together.

• | System voltage is too high or too low.

• | Transaxle input voltage is too high or too low.

• | Immediately after the above condition occurs

### Action Taken When the DTC Sets

• | The malfunction indicator lamp (MIL) will illuminate.

• | The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.

• | Adopt Emergency/Substitute mode and constant 4th gear by hydraulic control.

• | After ignition OFF/ON : 3rd gear by hydraulic control. Possible P, R and N also possible.

• | Power supply cut off to the pressure control solenoid (PCS) valve.

### Conditions for Clearing the MIL/DTC

• | The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles.

• | A history DTC will clear after 40 consecutive warm-up cycles.

• | Using a scan tool can clear history DTCs.

### Diagnostic Aids

When DTC P0603 sets, the possible cause of fault could be TCM.

#### DTC P0603

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.

Does the scan tool display P0603?

Go to Step 3

Go to Diagnostic Aids

3 |

1. Turn the ignition OFF.
2. Replace the transmission control module (TCM). Refer to Transmission Control Module Replacement .

Is the replacement complete?

Go to Step 4

--

4 |

1. Using the scan tool, clear the DTCs.
2. Road test the vehicle within the Conditions for Setting this DTC, as specified in the text.

Does the scan tool indicate that this diagnostic has run and passed?

Go to Step 5

Go to Step 2

5 | Inspect if any DTCs are set. Are any DTCs displayed that have not been diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK