Code No.52: Valve Relay OFF Defective


















caution If there is any problem in the CAN bus lines, an incorrect diagnosis code may be set. Diagnose the CAN bus lines before the diagnosis codes (Refer to GROUP 54D, CAN bus-line diagnostic flow ).

OPERATION


HBB is supplied with power for drive of each solenoid valve from the fusible link No. 31 by turning ON the valve relay, and the drive of each solenoid valve is controlled by ASTC-ECU.

DIAGNOSIS CODE SET CONDITIONS


Diagnosis code No. 52 is set if ASTC-ECU judges that power for the solenoid valve is not supplied when ASTC-ECU turns ON the valve relay.

PROBABLE CAUSES


The most likely causes for these diagnosis codes to set are:

  • Damaged wiring harness or connector
  • Malfunction of the valve relay
  • Malfunction of the ASTC-ECU

DIAGNOSIS


STEP 1. M.U.T.-III CAN bus diagnostics


caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
(1)Connect M.U.T.-III to the 16-pin diagnosis connector.
(2)Turn the ignition switch to the "ON" position.
(3)Diagnose the CAN bus line.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the check result normal?

Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54D, CAN bus line Diagnostic flow ). Then go to Step 2.

STEP 2. Check whether the diagnosis code is reset.


caution Before connecting or disconnecting the M.U.T.-III, turn the ignition switch to the "LOCK" (OFF) position.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.52 set?

Go to Step 3.
The procedure is complete.

STEP 3. Check the valve relay.


Refer to .

Q. Is the check result normal?

Go to Step 4.
Replace the valve relay. Then go to Step 10.

STEP 4. Check valve relay connector B-17X, Diode connector B-109, ASTC-ECU connector D-232 and ASTC-ECU connector D-233 for loose, corroded or damaged terminals, or terminals pushed back in the connector.


Q. Is the check result normal?

Go to Step 5.
Repair or replace the damaged component(s). Then go to Step 10.

STEP 5. Check the harness wires between valve relay connector B-17X terminal No.4 and earth.


Check for open circuit to power supply.

Q. Is the check result normal?

Go to Step 6.
Repair the wiring harness. Then go to Step 10.

STEP 6. Check the harness wires between valve relay connector B-17X terminal No.2 and ASTC-ECU connector D-232 terminal No.62.


caution When checking the wiring harness continuity using the circuit tester, be sure to apply voltage in a correct direction because the diode is mounted on the circuit.
Check for open circuit or short to power supply.

Q. Is the check result normal?

Go to Step 7.
Repair the wiring harness. Then go to Step 10.

STEP 7. Check the harness wires between valve relay connector B-17X terminal No.5 and fusible link No.31.


Check for open circuit or short to earth.

Q. Is the check result normal?

Go to Step 8.
Repair the wiring harness. Then go to Step 10.

STEP 8. Check the harness wires between valve relay connector B-17X terminal No.1 and ASTC-ECU connector D-233 terminal No.18.


Check for open circuit.

Q. Is the check result normal?

Go to Step 9.
Repair the wiring harness. Then go to Step 10.

STEP 9. Check whether the diagnosis code is reset.


Check again if the diagnosis code is set.
(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is reset.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.52 set?

Replace the ASTC-ECU. Then go to Step 10.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction .

STEP 10. Check whether the diagnosis code is reset.


(1)Turn the ignition switch to the "ON" position.
(2)Erase the diagnosis code.
(3)Turn the ignition switch to the "LOCK" (OFF) position.
(4)Turn the ignition switch to the "ON" position.
(5)Check if the diagnosis code is set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.52 set?

Repeat the troubleshooting from Step 1.
The procedure is complete.