Code No. C1273: Motor Relay (Stuck Off)




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 54C, CAN bus-line diagnostic flow ).

OPERATION



DIAGNOSIS CODE SET CONDITIONS



PROBABLE CAUSES




  • Damaged wiring harness or connector
  • Malfunction of the hydraulic unit assembly (integrated with 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 54C, 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.C1273 set?

Go to Step 3.

The procedure is complete.

STEP 3. Check ASTC-ECU connector A-48, ABS motor relay connector A-49X and ABS failsafe relay connector A-50X for loose, corroded or damaged terminals, or terminals pushed back in the connector.



Q. Is the check result normal?

Go to Step 4.

Repair or replace the damaged component(s). Then go to Step 8.

STEP 4. Check the harness wires between ASTC-ECU connector A-48 terminal 15 and ABS motor relay connector A-49X terminal 4.



Q. Is the check result normal?

Go to Step 5.

Repair the wiring harness. Then go to Step 8.

STEP 5. Check the harness wires between ABS failsafe relay connector A-50X terminal 4 and ABS motor relay connector A-49X terminal 2.


Q. Is the check result normal?

Go to Step 6.

Repair the wiring harness. Then go to Step 8.

STEP 6. Check the harness wires between ABS failsafe relay connector A-50X terminal 2 and fusible link No.22.



Q. Is the check result normal?

Go to Step 7.

Repair the wiring harness. Then go to Step 8.

STEP 7. 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 set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.C1273 set?

Replace the hydraulic unit assembly (integrated with ASTC-ECU). Then go to Step 8.

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 8. Check that the ABS warning lamp, brake warning lamp, ASTC indicator lamp and ASTC OFF indicator lamp are turned OFF.
Check that the ABS warning lamp, Brake warning lamp, ASTC indicator lamp and ASTC OFF indicator lamp goes out when the vehicle is driven at 10km/h or more.

Q. Does the ABS warning lamp go out?
Go to Step 9.
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 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 set.
(6)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is code No.C1273 set?

Go to Step 1.

The procedure is complete.