DTC P0850:23 [START STOP UNIT]

id0902p6023200

Description	Transaxle range sensor circuit malfunction
Detection condition	• The start stop unit detected the following condition 5 times continuously with the ignition switched ON (engine off or on). ? A transaxle range sensor signal is in the P or N position for a continuous 1 s or more even though the TCM CAN signal is in a position other than the P and N positions.
Fail-safe	• Perform control of the internal signal for control of the transaxle range sensor as position other than P, N positions.
Possible cause	• DTCs are stored in the TCM. • TCM connector or terminal malfunction • PCM connector or terminal malfunction • Start stop unit connector or terminal malfunction • Short to ground in wiring harness between the following terminals: ? PCM terminal 2BD?TCM terminal J ? Start stop unit terminal 1F?TCM terminal J • Open circuit in wiring harness between the following terminals: ? PCM terminal 2BD?TCM terminal J ? Start stop unit terminal 1F?TCM terminal J • Transaxle range sensor malfunction • PCM malfunction • Start stop unit malfunction

Diagnostic Procedure

Step	Inspection		Action
1	VERIFY TCM DTCs • Retrieve the TCM DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (GW6A-EL, GW6AX-EL)].) • Are any DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [TCM (GW6A-EL, GW6AX-EL)].)
1		No	Go to the next step.
2	INSPECT TCM CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • 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.
2		No	Repair or replace the connector, then go to Step 9.
3	INSPECT PCM CONNECTOR CONDITION • Disconnect the PCM 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.
3		No	Repair or replace the connector, then go to Step 9.
4	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.
4		No	Repair or replace the connector, then go to Step 9.
5	INSPECT TRANSAXLE RANGE SENSOR CIRCUIT FOR SHORT TO GROUND • Verify that the TCM, PCM and start stop unit connectors are disconnected. • Inspect for continuity between start stop unit terminal 1F (wiring harness-side) and body ground. • Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • PCM terminal 2BD?TCM terminal J • Start stop unit terminal 1F?TCM terminal J If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to ground. Go to Step 9.
5		No	Go to the next step.
6	INSPECT TRANSAXLE RANGE SENSOR CIRCUIT FOR OPEN CIRCUIT • Verify that the TCM, PCM and start stop unit connectors are disconnected. • Inspect for continuity between the following terminals (wiring harness-side): ? PCM terminal 2BD?TCM terminal J ? Start stop unit terminal 1F?TCM terminal J • Is there continuity?	Yes	Go to the next step.
6		No	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: • PCM terminal 2BD?TCM terminal J • Start stop unit terminal 1F?TCM terminal J If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to Step 9.
7	VERIFY IF MALFUNCTIONING LOCATION IS TRANSAXLE RANGE SENSOR DEPENDING ON REPEATABILITY • Always reconnect all disconnected connectors. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC for the start stop unit using the M-MDS. (See CLEARING DTC [START STOP UNIT].) • Switch the ignition ON (engine off). • Perform the following work 5 times or more. ? Operate the selector lever to other than P and N position and wait for 1 s or more. ? Operate the selector lever to P or N position and wait for 1 s or more. ? Operate the selector lever to other than P and N position. • Retrieve the start stop unit DTCs using the M-MDS. (See DTC INSPECTION [START STOP UNIT].) • Is the same DTC displayed?	Yes	Replace the TCM, then go to the next step. (See CONTROL VALVE BODY REMOVAL/INSTALLATION [GW6A-EL, GW6AX-EL].)
7		No	Go to Step 10.
8	VERIFY IF MALFUNCTIONING LOCATION IS PCM DEPENDING ON REPEATABILITY • Clear the DTC for the start stop unit using the M-MDS. (See CLEARING DTC [START STOP UNIT].) • Switch the ignition ON (engine off). • Perform the following work 5 times or more. ? Operate the selector lever to other than P and N position and wait for 1 s or more. ? Operate the selector lever to P or N position and wait for 1 s or more. ? Operate the selector lever to other than P and N position. • Retrieve the start stop unit DTCs using the M-MDS. (See DTC INSPECTION [START STOP UNIT].) • Is the same DTC displayed?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
8		No	Go to Step 10.
9	VERIFY THAT REPAIRS HAVE BEEN COMPLETED • Always reconnect all disconnected connectors. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC for the start stop unit using the M-MDS. (See CLEARING DTC [START STOP UNIT].) • Switch the ignition ON (engine off). • Perform the following work 5 times or more. ? Operate the selector lever to other than P and N position and wait for 1 s or more. ? Operate the selector lever to P or N position and wait for 1 s or more. ? Operate the selector lever to other than P and N position. • Retrieve the start stop unit DTCs using the M-MDS. (See DTC INSPECTION [START STOP UNIT].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the start stop unit. (See START STOP UNIT REMOVAL/INSTALLATION.) Go to the next step.
9		No	Go to the next step.
10	VERIFY IF OTHER DTCs DISPLAYED • Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE [START STOP UNIT].)
10		No	DTC troubleshooting completed.