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Home >> Mitsubishi >> 2002 >> Galant ES L4-2350cc 2.4L SOHC MFI >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> Transmission Control System >> DTC 54

DTC 54

DTC 54: A/T Control Relay System









CIRCUIT OPERATION
^ A/T control relay (terminal number 1) receives the battery positive voltage from the battery.
^ When turning the ignition switch to the "ON" position the PCM receives battery voltage from the ignition switch (terminal 98). Then the PCM (terminal number 50) applies a voltage to the A/T control relay (terminal number 2), and the A/T control relay switch is turned on.
^ When the A/T control relay switch is fumed on, the battery applies a power supply voltage to the PCM (terminal numbers 77 and 89).

DTC SET CONDITIONS
If the A/T control relay voltage is less than 7 volts at terminals 77 and 89 after the ignition switch has been turned to the "ON" position, it is judged that there is an open circuit or a short-circuit in the A/T control relay ground and diagnostic trouble code number "54" is output. The transmission is locked into the 3rd gear as a fail-safe measure.

TROUBLESHOOTING HINTS (The most likely causes for this code to be set:)
^ Malfunction of the A/T control relay
^ Damaged harness, connector
^ Malfunction of the PCM

DIAGNOSIS
Required Special Tool: MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check data list item 54: A/T Control Relay Output Voltage.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.





1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Set scan tool MB991502 to data reading mode for item 54: A/T Control Relay Output Voltage.
^ Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the relay operating properly?
YES: This malfunction is intermittent.
NO: Go to Step 2.

STEP 2. Check the A/T control relay.





1. Remove the A/T control relay A-17X.





2. Use jumper wires to terminal 3 of A/T control relay connector A-17X to the negative battery terminal, and terminal number 2 of A/T control relay connector A-17X to the positive battery terminal.
3. Measure the resistance between terminal 1 and 4 of A/T control relay connector A-17X.
^ Should be than 2 ohm when the jumper wire connected.
^ Open circuit when the jumper wire disconnected.
Q: Is the resistance normal?
YES: Go to Step 3.
NO: Replace the A/T control relay.





STEP 3. Check connector A-17X at A/T control relay for damage.
Q: Is the connector in good condition?
YES: Go to Step 4.
NO: Repair or replace it.

STEP 4. Check the power supply voltage at A/T control relay connector A-17X.





1. Disconnect the A/T control relay and measure at the connector side.
2. Turn the ignition switch to "ON" position.





3. Measure the voltage between terminal 1 and ground.
^ Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 6.
NO: Go to Step 5.





STEP 5. Check connector C-04 at intermediate connector for damage.
Q: Is the connector in good condition?
YES: Repair harness open circuit or short circuit to ground between A/T control relay connector A-17X terminal 1 and battery.
NO: Repair or replace it.

STEP 6. Check the continuity at A/T control relay connector A-17X.





1. Disconnect the A/T control relay and measure at the connector side.





2. Check for the continuity between terminal 3 and ground.
^ Should be less than 2 ohm.
Q: Is the continuity normal?
YES: Go to Step 7.
NO: Rapier harness open circuit or damage between A/T control relay connector A-17X terminal 3 and the earth.

STEP 7. Check the power supply voltage at A/T control relay connector A-17X.





1. Disconnect the A/T control relay and measure at the connector side.





2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 2 and ground.
^ Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 11.
NO: Go to Step 8.

STEP 8. Check the power supply voltage at PCM connector C40 by backprobing.





1. Do not disconnect connector C-40.





2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 50 and ground by backprobing.
^ Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 9.
NO: Go to Step 10.





STEP 9. Check connector C40 at PCM for damage.
Q: Is the connector in good condition?
YES: Repair harness open circuit between A/T control relay connector A-17X terminal 2 and PCM connector C-40 terminal 50.
NO: Repair or replace it.








STEP 10. Check for short circuit to ground between A/T control relay connector A-17X terminal 2 and PCM connector C-40 terminal 50.
Q: Is the harness wire in good condition?
YES: Go to Step 11.
NO: Repair it.





STEP 11. Using scan tool MB991502, check data list item 54: A/T control relay output Voltage.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Set scan tool MB991502 to data reading mode for item 54: A/T Control Relay Output Voltage.
^ Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the relay operating properly?
YES: This malfunction is intermittent.
NO: Replace the PCM.

STEP 12. Check the relay output voltage at PCM connector C-41 by backprobing.





1. Do not disconnect connector C-41.
2. Turn the ignition switch to "ON" position.





3. Measure the voltage between terminal 77 and ground by backprobing.
^ Voltage should be battery positive voltage.





4. Measure the voltage between terminal 89 and ground by backprobing.
^ Voltage should be battery positive voltage.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the voltage normal?
YES: Go to Step 11.
NO: Go to Step 13.





STEP 13. Check connector C-41 at PCM for damage.
Q: Is the connector in good condition?
YES: Go to Step 14.
NO: Repair or replace it.








STEP 14. Check harness for short circuit to ground, open circuit or damage between A/T control relay connector A-17X terminal 4 and PCM connector C-41 terminals 77 and 89.
Q: Is the harness wire in good condition?
YES: Go to Step 15.
NO: Repair it.





STEP 15. Check harness for damage between A/T control relay connector A-17X terminal 1 and battery.
Q: Is the harness wire in good condition?
YES: Go to Step 16.
NO: Repair it.





STEP 16. Check harness for damage between A/T control relay connector A-17X terminal 3 and the ground.
Q: Is the harness wire in good condition?
YES: Go to Step 17.
NO: Repair it.








STEP 17. Check harness for short circuit to ground between A/T control relay connector A-17X terminal 2 and PCM connector C-40 terminal 50.
Q: Is the harness wire in good condition?
YES: Confirm DTC is eliminated.
NO: Repair harness short circuit to ground between A/T control relay connector A-17X terminal 4 and solenoid valve assembly connector B-38 terminal 9.


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