Code No.C1223: G and yaw rate sensor (active check error)
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 code (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
OPERATION
The G and yaw rate sensor is energized by the ignition switch (IG1) and the G and yaw rate sensor terminal 1.
The G and yaw rate sensor output signal is sent to the ASTC-ECU via the private CAN bus line.
DIAGNOSIS CODE SET CONDITION
The diagnosis code is set if the first G and yaw rate sensor check is not completed within the specified time although ASTC-ECU input voltage is normal when the ignition switch is turned ON.
PROBABLE CAUSES
Malfunction of the G and yaw rate sensor
Damaged wiring harness or connector
Malfunction of the hydraulic unit (integrated with ASTC-ECU)
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnosis
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics table ). On completion, go to Step 2.
STEP 2. Diagnosis code recheck after resetting CAN bus lines
Q.
Is the diagnosis code No.C1223 set?
Go to Step 3.
This diagnosis is complete.
STEP 3. Connector check: C-144 G and yaw rate sensor connector, C-132 joint connector, C-137 joint connector and C-138 joint connector
Q.
Is the check result normal?
Go to Step 4.
Repair the defective connector. Then go to Step 9.
STEP 4. Resistance measurement at the C-144 G and yaw rate sensor connector
(1)Disconnect the connector C-144 G and yaw rate sensor connector and measurement at the harness-side connector. (2)Measure the resistance between the C-144 G and yaw rate sensor connector terminal No.4 and body earth. OK: Continuity exists (2 Ω or less)
Q.
Is the check result normal?
Go to Step 6.
Go to Step 5.
STEP 5. Resistance measurement at the C-137 joint connector
(1)Disconnect the connector C-137 joint connector and measurement at the harness-side connector. (2)Measure the resistance between the C-144 G and yaw rate sensor connector terminal No.19 and body earth. OK: Continuity exists (2 Ω or less)
Q.
Is the check result normal?
An open circuit may be present. Repair the harness wire between C-138 joint connector terminal No.13 and C-144 G and yaw rate sensor connector terminal No.4. Then go to Step 9.
An open circuit may be present. Repair the harness wire between C-137 joint connector terminal No.19 and body earth. Then go to Step 9.
STEP 6. Voltage measurement at the C-144 G and yaw rate sensor connector
(1)Disconnect the connector C-144 G and yaw rate sensor connector and measurement at the harness-side connector. (2)Turn the ignition switch to the "ON" position. (3)Measure the voltage between the C-144 G and yaw rate sensor connector terminal No.1 and body earth. OK: System voltage
Q.
Is the check result normal?
Go to Step 7.
An open circuit may be present. Repair the wiring harness between the C-144 G and yaw rate sensor connector terminal No.1 and the C-132 joint connector terminal No.19. Then go to Step 9.
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.C1223 set?
Replace the G and yaw rate sensor (Refer to ). Then go to Step 8.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
STEP 8. 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.C1223 set?
Replace the hydraulic unit (integrated with ASTC-ECU) (Refer to ). Then go to Step 9.
The procedure is complete.
STEP 9. Recheck for diagnosis code.
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.
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Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics table 
). On completion, go to Step 2.)
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