Inspection Procedure 17: ACC power auto cut function does not work normally.


caution Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

COMMENTS ON TROUBLE SYMPTOM


The KOS&OSS-ECU will evaluate the signals from the power supply mode (ACC) and the driver’s door switch to determine whether the ACC power supply is shut down or not. If this function does not work normally, the input signal or the KOS&OSS-ECU may be defective. Also, "ACC automatic cut timer (OSS)" may be set to "Disable" through customisation.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. Check of customisation function


Use the ETACS-ECU customisation function to check whether "ACC automatic cut timer (OSS)" is set to 30 min or 60 min.

Q. Is the check result normal?

Go to Step 2.

Using the ETACS-ECU customisation function, set "ACC automatic cut timer (OSS)" to 30 min or 60 min (Refer to ).

STEP 2. M.U.T.-III diagnosis code


Check if any diagnosis code is set in the KOS&OSS-ECU.

Q. Is the diagnosis code set?

Refer to diagnosis code chart .

Go to Step 3.

STEP 3. Check of short to earth in PDSW line between selector lever assembly connector and KOS&OSS-ECU connector


note Because the conformity cannot be determined even when the digital tester is used to measure the voltage of PDSW line between the selector lever assembly connector and KOS&OSS-ECU connector, be sure to use the oscilloscope (Outputs the sawtooth waveform of 0 to 5 V with intervals of 10 ms).

Q. Is the check result normal?

Go to Step 4.

Repair the connector(s) or wiring harness.

STEP 4. Check of selector lever assembly (P range detection switch)


Disconnect the selector lever assembly connector, and check the continuity at the equipment side.
Operation state
 Terminal No.
 Normal conditions
Selector lever: P position
 4 - 6
 No continuity
Selector lever: Other than P position
 Continuity exists (2 Ω or less)

Q. Is the check result normal?

Go to Step 5.

Replace the selector lever assembly.

STEP 5. M.U.T.-III data list


Check the KOS&OSS-ECU data list.

Item No.
 Check item
 Operation state
 Display
24
 P range detect SW
 Selector lever: P position
 Outside park
Selector lever: Other than P position
 Park
OK: Operation state and data list display agree with each other.

Q. Is the check result normal?

Go to Step 6.

Replace the KOS&OSS-ECU and register the chassis number (Refer to ).

STEP 6. M.U.T.-III other system data list


Check the ETACS-ECU data list.

Open the driver’s door.
Item No.
 Check item
 Normal conditions
19
 Driver’s door switch
 ON
OK: Normal conditions are displayed.

Q. Is the check result normal?

Go to Step 7.

Perform input signal check for the ETACS (Refer to GROUP 54A - ETACS - Input signal check ).

STEP 7. Voltage measurement at KOS&OSS-ECU connector


Check the voltage measurement at KOS&OSS-ECU connector (Refer to ).
Terminals to be checked

Q. Is the check result normal?

Go to Step 8.

Replace the KOS&OSS-ECU and register the chassis number (Refer to ).

STEP 8. M.U.T.-III data list


Use the KOS&OSS-ECU service data to check the signals related to the ACC power auto cut function.

Item No.
 Check item
 Normal conditions
27
 OSS power supply status
 IG ACC
OK: Normal conditions are displayed.

Q. Is the check result normal?

Go to Step 9.

Replace the KOS&OSS-ECU and register the chassis number (Refer to ).

STEP 9.Check of the troubles


Check whether the ACC power auto cut function works normally.

Q. Is the check result normal?

Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).

Replace the KOS&OSS-ECU and register the chassis number (Refer to ).