DTC P0850:24 [START STOP UNIT]

id0902p6023300

Description

Transmission range switch circuit malfunction

Detection condition

•  The start stop unit detected the following condition 5 times continuously with the ignition switched ON (engine off or on).

―  Transmission range switch is stuck off for a continuous 1 s or more even though the TCM CAN signal is in a position the P or N position.

Fail-safe

•  Perform control of the internal signal for control of the transmission range switch as position other than P, N positions.

Possible cause

•  DTCs are stored in the TCM.

•  Transmission range switch connector or terminal malfunction

•  Open circuit in wiring harness between transmission range switch terminal A and body ground

•  PCM connector or terminal malfunction

•  Start stop unit connector or terminal malfunction

•  Open circuit in wiring harness between the following terminals:

―  PCM terminal 2BD—Transmission range switch terminal I

―  Start stop unit terminal 1F—Transmission range switch terminal I

•  Transmission range switch malfunction

•  PCM malfunction

•  Start stop unit malfunction

Description	Transmission range switch circuit malfunction
Detection condition	• The start stop unit detected the following condition 5 times continuously with the ignition switched ON (engine off or on). ― Transmission range switch is stuck off for a continuous 1 s or more even though the TCM CAN signal is in a position the P or N position.
Fail-safe	• Perform control of the internal signal for control of the transmission range switch as position other than P, N positions.
Possible cause	• DTCs are stored in the TCM. • Transmission range switch connector or terminal malfunction • Open circuit in wiring harness between transmission range switch terminal A and body ground • PCM connector or terminal malfunction • Start stop unit connector or terminal malfunction • Open circuit in wiring harness between the following terminals: ― PCM terminal 2BD—Transmission range switch terminal I ― Start stop unit terminal 1F—Transmission range switch terminal I • Transmission range switch 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 (SJ6A-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 (SJ6A-EL)].)
1		No	Go to the next step.
2	INSPECT TRANSMISSION RANGE SWITCH CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the transmission range switch 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 TRANSMISSION RANGE SWITCH GROUND CIRCUIT FOR OPEN CIRCUIT • Verify that the transmission range switch connector is disconnected. • Inspect for continuity between transmission range switch terminal A (wiring harness-side) and body ground. • Is there continuity?	Yes	Go to the next step.
3		No	Refer to the wiring diagram and verify whether or not there is a common connector between transmission range switch terminal A and body ground. 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.
4	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.
4		No	Repair or replace the connector, then go to Step 9.
5	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.
5		No	Repair or replace the connector, then go to Step 9.
6	INSPECT TRANSMISSION RANGE SWITCH CIRCUIT FOR OPEN CIRCUIT • Verify that the start stop unit, PCM and transmission range switch connectors are disconnected. • Inspect for continuity between the following terminals (wiring harness-side): ― PCM terminal 2BD—Transmission range switch terminal I ― Start stop unit terminal 1F—Transmission range switch terminal I • 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—Transmission range switch terminal I • Start stop unit terminal 1F—Transmission range switch terminal I 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	INSPECT TRANSMISSION RANGE SWITCH • Inspect the transmission range switch. (See TRANSMISSION RANGE (TR) SWITCH INSPECTION [SJ6A-EL].) • Is the transmission range switch normal?	Yes	Go to the next step.
7		No	Replace the transmission range switch, then go to Step 9. (See TRANSMISSION RANGE (TR) SWITCH REMOVAL/INSTALLATION [SJ6A-EL].)
8	VERIFY IF MALFUNCTIONING LOCATION IS PCM 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 P or N position and wait for 1 s 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. • Retrieve the start stop unit DTCs using the M-MDS. (See DTC INSPECTION [START STOP UNIT].) • Is the same Pending DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 1.5, SKYACTIV-G 2.0].)
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 P or N position and wait for 1 s 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. • Retrieve the start stop unit DTCs using the M-MDS. (See DTC INSPECTION [START STOP UNIT].) • Is the same Pending DTC present?	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.