Code No.54: A/T control relay system
OPERATION
If a fail-safe operation is activated, the A/T control relay shuts off the power supply to the solenoid valve in accordance with the signal from the engine-A/T-ECU.
DIAGNOSIS CODE SET CONDITIONS
Code No.54 will be set if the A/T control voltage is less than 7 V after the ignition switch is turned on.
If code No.54 is set, the transmission will be held in 3rd gear.
PROBABLE CAUSES
- Malfunction of A/T control relay
- Damaged harness wires and connectors
- Malfunction of the engine-A/T-ECU
|
|
STEP 1. M.U.T.-III data list
|
|
|
Item 54: Relay voltage (Refer to data list reference table  ).
|
|
|
Q.
Is the check result normal?
|
|
|
 Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
|
|
|
|
|
|
 Go to Step 2.
|
|
|
|
|
|
STEP 2. Check the A/T control relay connector
|
|
|
Refer to .
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 3.
|
|
|
|
|
|
Replace the A/T control relay.
|
|
|
|
|
|
STEP 3. Connector check: B-14X A/T control relay connector
|
|
Check for the contact with terminals.
Q.
Is the check result normal?
Go to Step 4.
Repair the defective connector.
|
|
|
STEP 4. Measure the voltage at A/T control relay connector B-14X.
|
|
Disconnect the A/T control relay, and measure the voltage between terminal No.4 and earth at the relay box side.
OK: System voltage
Q.
Is the check result normal?
Go to Step 8.
Go to Step 5.
|
|
|
STEP 5. Connector check: A-16 intermediate connector
|
|
Check for the contact with terminals.
Q.
Is the check result normal?
Go to Step 6.
Repair the defective connector.
|
|
|
STEP 6. Check the harness between A/T control relay connector B-14X terminal No.4 and battery.
|
|
Check the power supply line for short or open circuit.
Q.
Is the check result normal?
Go to Step 7.
Repair the wiring harness.
|
|
|
STEP 7. M.U.T.-III data list
|
|
|
Item 54: Relay voltage (Refer to data list reference table ).
|
|
|
Q.
Is the check result normal?
|
|
|
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
|
|
|
|
|
|
Replace the engine-A/T-ECU.
|
|
|
|
|
|
STEP 8. Measure the voltage at the A/T control relay connector B-14X.
|
|
|
(1)Turn the ignition switch to the ON position.
|
|
(2)Disconnect the A/T control relay, and measure the voltage between terminal No.3 and earth at the relay box side.
OK: System voltage
Q.
Is the check result normal?
Go to Step 11.
Go to Step 9.
|
|
|
STEP 9. Connectors check: C-116 J/C (4), C-18 intermediate connector, C-203 J/B connector
|
|
Check for the contact with terminals.
Q.
Is the check result normal?
Go to Step 10.
Repair the defective connector.
|
|
|
STEP 10. Check the wiring harness between A/T control relay connector B-14X terminal No.3 and junction block connector C-203 terminal No.12.
|
|
Check the power supply line for short or open circuit.
Q.
Is the check result normal?
Go to Step 7.
Repair the wiring harness.
|
|
|
STEP 11. Measure the voltage at engine-A/T-ECU connector C-114.
|
|
|
(1)Install the A/T control relay.
|
|
|
(2)Turn the ignition switch to the ON position.
|
|
(3)Measure the voltage between engine-A/T-ECU connector C-114 terminal No.123, No.124 and earth.
OK: System voltage
Q.
Is the check result normal?
Go to Step 14.
Go to Step 12.
|
|
|
STEP 12. Connector check: C-114 engine-A/T-ECU connector
|
|
Check for the contact with terminals.
Q.
Is the check result normal?
Go to Step 13.
Repair the defective connector.
|
|
|
STEP 13. Check the harness between A/T control relay connector B-14X terminal No.1 and engine-A/T-ECU connector C-114 terminal No.123, 124.
|
|
Check the power supply line for short or open circuit.
Q.
Is the check result normal?
Go to Step 7.
Repair the wiring harness.
|
|
|
STEP 14. Connector check: C-114 engine-A/T-ECU connector
|
|
Check for the contact with terminals.
Q.
Is the check result normal?
Go to Step 15.
Repair the defective connector.
|
|
|
STEP 15. Check the harness between A/T control relay connector B-14X terminal No.2 and engine-A/T-ECU connector C-114 terminal No.127.
|
|
Check the output line for short or open circuit.
Q.
Is the check result normal?
Go to Step 7.
Repair the wiring harness.
|
)
)
)
)
)
)
)
)