DTC B227C: P Range Signal Performance

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

DTC detecting condition:

When any of the following conditions is established for CVT model.

The status continues for 20 seconds where the ignition switch is ON, and the shift position (P terminal) is in shift P ("L" level), and the shift information on CAN is other than P.
The status continues for 20 seconds where the ignition switch is ON, and the shift position (P terminal) is in other than shift P ("H" level), and the shift information on CAN is P.

Trouble symptom:

Engine will not start.
Power supply control cannot be executed.
The steering lock is not possible.

Wiring diagram:

Keyless access with push button start system Ref. to WIRING SYSTEM>KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM>WIRING DIAGRAM
CAN communication system Ref. to WIRING SYSTEM>CAN COMMUNICATION SYSTEM>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

CAUTION:

For replacement procedure of keyless access control module, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.
Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION

CHECK DTC .
1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, perform the clear memory of [Keyless Access with Push Button Start (Power Supply)] and [Keyless Access with Push Button Start (Collation)]. Ref. to COMMON (DIAGNOSTICS)>CLEAR MEMORY
  - Keyless Access with Push Button Start (Power Supply)
  - Keyless Access with Push Button Start (Collation)
3. Place the shift lever in other than P and leave it for one minute.
4. Turn the ignition switch to OFF.
5. Disconnect the connector from the keyless access control module and reconnect it.
6. Turn the ignition switch to ON.
7. Using the Subaru Select Monitor, read the DTCs of [Keyless Access with Push Button Start (Power Supply)] and [Keyless Access with Push Button Start (Collation)]. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)
  - Keyless Access with Push Button Start (Power Supply)
  - Keyless Access with Push Button Start (Collation)
Is DTC B227C displayed? (Current code)

Yes : Go to 2.

No : Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE:
In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
CHECK HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from the P range switch.
3. Disconnect the connector from the keyless access control module.
4. Using a tester, measure the resistance between the P range switch connector and the keyless access control module connector.
  Connector & terminal
  
  (i136) No. 1 - (i92) No. 18:
Is the resistance less than 1 Ω?

Yes : Go to 3.

No : Repair or replace the open circuit of harness.
CHECK HARNESS (GROUND SHORT CIRCUIT) .
Using a tester, measure the resistance between the keyless access control module connector and chassis ground.

Connector & terminal

(i92) No. 18 - Chassis ground:

Is the resistance 10 kΩ or more?

Yes : Go to 4.

No : Repair or replace the short circuit of the harness.
CHECK HARNESS (OPEN CIRCUIT) .
1. Disconnect the central gateway control module connector.
2. Using a tester, measure the resistance between the central gateway control module connector and keyless access control module connector.
  Connector & terminal
  
  (i88) No. 5 - (i92) No. 30
  
  (i88) No. 6 - (i92) No. 29
Is the resistance less than 1 Ω?

Yes : Go to 5.

No : Repair or replace the open circuit of harness.
CHECK P RANGE SWITCH .
Check the P range switch. Ref. to CONTROL SYSTEMS>SHIFT LOCK SOLENOID AND P RANGE SWITCH>INSPECTION

Is the check result OK?

Yes : Go to 6.

No : Replace the P range switch. Ref. to CONTROL SYSTEMS>SHIFT LOCK SOLENOID AND P RANGE SWITCH>REMOVAL
CHECK DATA MONITOR .
1. Connect the disconnected connectors.
2. Turn the ignition switch to ON.
3. Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Keyless Access with Push Button Start (Power Supply)] and [Keyless Access with Push Button Start (Collation)]. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>DATA MONITOR
  - Keyless Access with Push Button Start (Power Supply)
    - Shift P signal (AT only)
  - Keyless Access with Push Button Start (Collation)
    - Shift P signal (AT only)
Is it turned [ON] when the shift position is in "P"? Is it turned [OFF] when the shift position is in other than "P"?

Yes : Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE:
In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

No : Replace the keyless access control module. Ref. to SECURITY AND LOCKS>KEYLESS ACCESS CONTROL MODULE>REMOVAL