DTC P0850:23 [START STOP UNIT]

id0902p6023200

System malfunction location

TCM circuit malfunction
Detection condition
•  With the ignition switched ON (engine off or on), it is detected that the transaxle range sensor CAN signal is P or N position for 1 s or more continuously for a continuous 5 or more times even though the TCM CAN signal is other than P and N position.
Fail-safe
•  Perform control of the internal signal for control of the transaxle range sensor as position other than P, N positions.
Possible cause
•  TCM connector or terminal malfunction
•  Start stop unit connector or terminal malfunction
•  Short to power supply in wiring harness between start stop unit terminal 1F and TCM terminal J
•  Transaxle range sensor malfunction
•  Start stop unit malfunction

Diagnostic Procedure

Step

Inspection

Action
1
INSPECT TCM CONNECTOR CONDITION
•  Switch the ignition to off.
•  Disconnect the negative battery cable.
•  Disconnect the TCM connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 5.
2
INSPECT START STOP UNIT CONNECTOR CONDITION
•  Disconnect the start stop unit connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 5.
3
INSPECT TCM CIRCUIT FOR SHORT TO POWER SUPPLY
•  Reconnect all the disconnected connectors.
•  Connect the negative battery cable.
•  Operate the selector lever to positions P or N.
•  Measure the voltage at start stop unit terminal 1F (vehicle wiring harness side).
•  Is the voltage 1.0 V or less?
Yes
Go to the next step.
No
Repair or replace the wiring harness which is shorted to power supply, then go to Step 5.
4
PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING PART IS TRANSAXLE RANGE SENSOR
•  Clear DTC for the start stop unit using the M-MDS.
•  Switch the ignition ON (engine off).
•  Perform the following work five or more times.
―  Operate the selector lever to positions P or N and wait for 1 s or more.
―  Operate the selector lever to positions R or D and wait for 1 s or more.
―  Operate the selector lever to positions P or N.
•  Perform the DTC inspection for the start stop unit using the M-MDS.
•  Is DTC P0850:23 displayed?
Yes
Replace the TCM, then go to the next step.
(See CONTROL VALVE BODY REMOVAL/INSTALLATION [FW6A-EL, FW6AX-EL].)
No
Go to Step 6.
5
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Reconnect all the disconnected connectors.
•  Reconnect the negative battery cable.
•  Clear DTC for the start stop unit using the M-MDS.
•  Switch the ignition ON (engine off).
•  Perform the following work five or more times.
―  Operate the selector lever to positions P or N and wait for 1 s or more.
―  Operate the selector lever to positions R or D and wait for 1 s or more.
―  Operate the selector lever to positions P or N.
•  Perform the DTC inspection for the start stop unit using the M-MDS.
•  Is DTC P0850:23 displayed?
Yes
Replace the start stop unit, then go to the next step.
(See START STOP UNIT REMOVAL/INSTALLATION.)
No
Go to the next step.
6
VERIFY IF OTHER DTCs DISPLAYED
•  Are any other DTCs displayed?
Yes
Repair the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [START STOP UNIT].)
No
DTC troubleshooting completed.