DTC B2284: Brake Signal Correlation

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:

The status continues for 20 seconds where brake signals (ON/OFF) between direct line and CAN do not match with ignition switch ON.

Trouble symptom:

If the hard-wired brake signal is faulty, the engine will not start with a normal operation.

Wiring diagram:

Stop light system Ref. to WIRING SYSTEM>STOP LIGHT SYSTEM>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 LAN SYSTEM .
Perform the diagnosis for LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE

Is the check result OK?

Yes : Go to 2.

No : Perform the inspection according to the diagnosis for LAN system.
CHECK DATA MONITOR .
1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Keyless Access with Push Button Start (Power Supply)]. Ref. to KEYLESS ACCESS WITH PUSH BUTTON START (DIAGNOSTICS)>DATA MONITOR
  - Stop Light Switch
Does the display change correctly according to the brake pedal operation?

Yes : Go to 3.

No : Check the stop light system. Ref. to LIGHTING SYSTEM>STOP LIGHT SYSTEM>INSPECTION
CHECK DATA MONITOR .
Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Body Control]. Ref. to BODY CONTROL (DIAGNOSTICS)>DATA MONITOR
- Stop Light Switch
Does the display change correctly according to the brake pedal operation?

Yes : Go to 4.

No : Check body integrated unit. Ref. to BODY CONTROL (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE And check the stop light switch circuit. Ref. to LIGHTING SYSTEM>STOP LIGHT SYSTEM>INSPECTION
CHECK FUSE .
1. Turn the ignition switch to OFF.
2. Check the fuse. Ref. to WIRING SYSTEM>KEYLESS ACCESS WITH PUSH BUTTON START SYSTEM>WIRING DIAGRAM
Is the check result OK?

Yes : Go to 5.

No : Replace the fuse. When the replaced fuse is blown immediately, check the power supply circuit for short-circuited.
CHECK HARNESS .
1. Disconnect the connector from the keyless access control module.
2. Using a tester, measure the voltage between the keyless access control module connector and chassis ground.
  Connector & terminal
  
  (i91) No. 1 (+) - Chassis ground (-):
  
  (i91) No. 4 (+) - Chassis ground (-):
Is the voltage 9.5 - 16 V?

Yes : Go to 6.

No : Check the power supply circuit.
CHECK HARNESS (OPEN CIRCUIT) .
Using a tester, measure the resistance between the keyless access control module connector and chassis ground.

Connector & terminal

(i92) No. 17 - Chassis ground:

(i91) No. 20 - Chassis ground:

Is the resistance less than 1 Ω?

Yes : Go to 7.

No : Repair or replace the open circuit of harness.
CHECK HARNESS (OPEN CIRCUIT) .
1. Disconnect the connector from stop light switch.
2. Using a tester, measure the resistance between the keyless access control module connector and stop light switch connector.
  Connector & terminal
  
  (i92) No. 27 - (B101) No. 2:
Is the resistance less than 1 Ω?

Yes : Go to 8.

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. 27 - Chassis ground:

Is the resistance 10 kΩ or more?

Yes : Go to 9.

No : Repair or replace the short circuit of the harness.
CHECK HARNESS .
1. Connect the disconnected connectors.
2. Using a tester, measure the voltage between the keyless access control module connector and chassis ground when the brake pedal is depressed.
  Connector & terminal
  
  (i92) No. 27 (+) - Chassis ground (-):
Does the voltage change as follows? Brake pedal not depressed: voltage of 1 V or less → Brake pedal depressed: voltage of 11 - 14 V

Yes : Replace the keyless access control module. Ref. to SECURITY AND LOCKS>KEYLESS ACCESS CONTROL MODULE>REMOVAL

No : Check the power supply circuit of stop light switch.