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Inspection Procedure 16: ACC power auto cut function does not work normally.
 
 
cautionBefore replacing the ECU, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.
 
 
TECHNICAL DESCRIPTION (COMMENT)
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 customization.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of KOS&OSS-ECU
  • Malfunction of the driver's door switch
  • External noise interruption in input signal
  • Malfunction of selector lever assembly (ON seizure of P range detection switch)
 
 
DIAGNOSIS
STEP 1. Check of customization.
Use the ETACS-ECU customization function to check whether "ACC automatic cut timer (OSS)" is set to 30 min or 60 min.
Is the check result normal?
Go to Step 2.
Using the ETACS-ECU customization function, set "ACC automatic cut timer (OSS)" to 30 min or 60 min (Refer to ).
 
STEP 2. Using scan tool (M.U.T.-III), read the diagnostic trouble code.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III) [Refer to "How to connect scan tool (M.U.T.-III) "].
(2) Turn the power supply mode of the engine switch to "ON".
(3) Check if the DTC is set in the KOS&OSS-ECU.
(4) Turn the power supply mode of the engine switch to "OFF".
Is the DTC set?
Refer to diagnostic trouble code chart .
Go to Step 3.
 
STEP 3. Check of short to ground in PDSW line between selector lever assembly connector and KOS&OSS-ECU connector.
noteBecause 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).
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 stateTerminal No.Normal conditions
Selector lever: P position4 - 6No continuity
Selector lever: Other than P positionContinuity exists (2 ohms or less)
Is the check result normal?
Go to Step 5.
Replace the selector lever assembly.
 
STEP 5. Using scan tool (M.U.T.-III), check data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III) [Refer to "How to connect the Scan Tool (M.U.T.-III) "].
(2) Turn the power supply mode of the engine switch to "OFF".
(3) Check the KOS&OSS-ECU data list.
  • Operate the selector lever.
 
Item No.Check itemOperation stateDisplay
24P range detect SWSelector lever: P positionOutside park
Selector lever: Other than P positionPark
OK: Operation state and data list display agree with each other.
Is the check result normal?
Go to Step 6.
Replace the KOS&OSS-ECU and register the chassis number (Refer to ).
 
STEP 6. Using scan tool (M.U.T.-III), check data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III) [Refer to "How to connect the Scan Tool (M.U.T.-III) "].
(2) Turn the power supply mode of the engine switch to "OFF".
(3) Check the ETACS-ECU service data relevant to the signal from the driver's door.
(1) Open the driver's door.
 
Item No.Check itemNormal conditions
19Driver's door switchON
OK: Normal conditions are displayed.
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
  • STP1
  • SW1
  • PDSW
  • SW2
Is the check result normal?
Go to Step 8.
Replace the KOS&OSS-ECU and register the VIN (Refer to ).
 
STEP 8. Using scan tool (M.U.T.-III), check data list.
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the power supply mode of the engine switch to the "OFF" position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III) [Refer to "How to connect the Scan Tool (M.U.T.-III) "].
(2) Turn the power supply mode of the engine switch to "OFF".
(3) Check the KOS&OSS-ECU data list.
  • Turn the power supply mode to ACC.
 
Item No.Check itemNormal conditions
27OSS power supply statusIG ACC
OK: Normal conditions are displayed.
Is the check result normal?
Go to Step 9.
Replace the KOS&OSS-ECU and register the VIN (Refer to ).
 
STEP 9.Check of the troubles.
Check whether the ACC power auto cut function works normally.
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 VIN (Refer to ).