Code No. C1291: Reverse signal (seizure)


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


ASTC-ECU monitors if the lever is shifted to the reverse position.

DIAGNOSIS CODE SET CONDITIONS


This code is set when the power supply and wheel speed sensor are normal and ASTC-ECU receives the signal that the shift lever is at the reverse position while the vehicle drives at 50 km/h or more.

PROBABLE CAUSES


The most likely causes for this diagnosis code to set is:

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.C1291 set?

Go to Step 3.

The procedure is complete.

STEP 3. Check ASTC-ECU connector A-48 and back-lamp switch connector B-02 <M/T> or inhibitor switch connector B-14 <A/T> for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is the check result normal?
Go to Step 4.
NO <M/T> : Check the back-lamp switch. (Refer to GROUP 22B, Transmission inspection .) Then go to Step 5.
NO <A/T> : Check if the automatic transmission outputs a diagnosis code. (Refer to GROUP 23A, Troubleshooting .) Then go to Step 5.

STEP 4. Check the harness wires between ASTC-ECU connector A-48 terminal 39 and back-lamp switch connector B-02 terminal 1 <M/T> or inhibitor switch connector B-14 terminal 8 <A/T>.

Q. Is the check result normal?
Go to Step 5.
Repair the wiring harness. Then go to Step 6.

STEP 5. 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.C1291 set?

Replace the hydraulic unit assembly (integrated with ASTC-ECU). Then go to Step 6.

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 6. 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.C1291 set?

Go to Step 1.

The procedure is complete.