[23A] AUTOMATIC TRANSMISSION (FF) - - TROUBLESHOOTING <A/T> - DIAGNOSTIC TROUBLE CODE PROCEDURES <4G69> - Code No.54: A/T Control Relay System | PRINT PAGE / INDEX / PRIOR / NEXT

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
DIAGNOSIS PROCEDURE
STEP 1. MUT-II/III data list Item 54: Relay voltage (Refer to data list reference table ). Q: Is the check result normal? YES: Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ). NO: Go to Step 2.
STEP 2. Check the A/T control relay connector Refer to . Q: Is the check result normal? YES: Go to Step 3. NO: Replace the A/T control relay.
STEP 3. Connector check: B-16X A/T control relay connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 4. NO: Repair the defective connector.
STEP 4. Measure the voltage at A/T control relay connector B-16X. 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? YES: Go to Step 8. NO: Go to Step 5.
STEP 5. Connector check: A-14 intermediate connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 6. NO: Repair the defective connector.
STEP 6. Check the harness between A/T control relay connector B-16X terminal No.4 and battery. Check the power supply line for short or open circuit. Q: Is the check result normal? YES: Go to Step 7. NO: Repair the wiring harness.
STEP 7. MUT-II/III data list Item 54: Relay voltage (Refer to data list reference table ). Q: Is the check result normal? YES: The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ). NO: Replace the engine-A/T-ECU.
STEP 8. Measure the voltage at the A/T control relay connector B-16X. Turn the ignition switch to the ON position. 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? YES: Go to Step 11. NO: Go to Step 9.
STEP 9. Connectors check: C-16 J/C(1), C-106 intermediate connector, C-202 J/B connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 10. NO: Repair the defective connector.
STEP 10. Check the wiring harness between A/T control relay connector B-16X terminal No.3 and junction block connector C-202 terminal No.12. Check the power supply line for short or open circuit. Q: Is the check result normal? YES: Go to Step 7. NO: Repair the wiring harness.
STEP 11. Measure the voltage at engine-A/T-ECU connector C-138. Install the A/T control relay. Turn the ignition switch to the ON position. Measure the voltage between engine-A/T-ECU connector C-138 terminal No.123, No.124 and earth. OK: System voltage Q: Is the check result normal? YES: Go to Step 14. NO: Go to Step 12.
STEP 12. Connector check: C-138 engine-A/T-ECU connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 13. NO: Repair the defective connector.
STEP 13. Check the harness between A/T control relay connector B-16X terminal No.1 and engine-A/T-ECU connector C-138 terminal No.123, No.124. Check the power supply line for short or open circuit. Q: Is the check result normal? YES: Go to Step 7. NO: Repair the wiring harness.
STEP 14. Connector check: C-138 engine-A/T-ECU connector Check for the contact with terminals. Q: Is the check result normal? YES: Go to Step 15. NO: Repair the defective connector.
STEP 15. Check the harness between A/T control relay connector B-16X terminal No.2 and engine-A/T-ECU connector C-138 terminal No.127. Check the output line for short or open circuit. Q: Is the check result normal? YES: Go to Step 7. NO: Repair the wiring harness.

[23A] AUTOMATIC TRANSMISSION (FF) - - TROUBLESHOOTING <A/T> - DIAGNOSTIC TROUBLE CODE PROCEDURES <4G69> - Code No.54: A/T Control Relay System | PRINT PAGE / INDEX / PRIOR / NEXT

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