Subaru Crosstrek Service Manual: Check power supply and ground line of engine control module (ecm)

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode Clear Memory Mode > OPERATION">, and Inspection Mode Inspection Mode > PROCEDURE">.

1.CHECK MAIN RELAY.

1) Turn the ignition switch to OFF.

2) Remove the main relay.

3) Connect the battery to main relay terminals No. 12 and No. 13.

4) Measure the resistance between main relay terminals.

Terminals

No. 10 — No. 11:

Is the resistance less than 1 ??

Diagnostics for Engine Starting Failure > CHECK POWER SUPPLY AND GROUND LINE OF ENGINE CONTROL MODULE (ECM)">Go to Step 2.

Replace the main relay. Main Relay">

2.CHECK GROUND CIRCUIT FOR ECM.

1) Disconnect the connector from ECM.

2) Measure the resistance of harness between ECM connector and chassis ground.

Connector & terminal

(B134) No. 3 — Chassis ground:

(B134) No. 4 — Chassis ground:

(B136) No. 1 — Chassis ground:

(B136) No. 2 — Chassis ground:

(B136) No. 3 — Chassis ground:

Is the resistance less than 5 ??

Diagnostics for Engine Starting Failure > CHECK POWER SUPPLY AND GROUND LINE OF ENGINE CONTROL MODULE (ECM)">Go to Step 3.

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit of harness between ECM connector and engine ground terminal

• Poor contact of coupling connector

3.CHECK INPUT VOLTAGE OF ECM.

1) Turn the ignition switch to ON.

2) Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B137) No. 2 (+) — Chassis ground (−):

(B137) No. 27 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Diagnostics for Engine Starting Failure > CHECK POWER SUPPLY AND GROUND LINE OF ENGINE CONTROL MODULE (ECM)">Go to Step 4.

Repair the open or ground short circuit of harness of power supply circuit.

4.CHECK INPUT VOLTAGE OF MAIN RELAY.

Measure the voltage between main relay connector and chassis ground.

Connector & terminal

(B220) No. 11 (+) — Chassis ground (−):

(B220) No. 12 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Diagnostics for Engine Starting Failure > CHECK POWER SUPPLY AND GROUND LINE OF ENGINE CONTROL MODULE (ECM)">Go to Step 5.

Repair the open or ground short circuit of harness of power supply circuit.

5.CHECK INPUT VOLTAGE OF ECM.

1) Turn the ignition switch to OFF.

2) Install the main relay.

3) Turn the ignition switch to ON.

4) Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B135) No. 13 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Diagnostics for Engine Starting Failure > CHECK POWER SUPPLY AND GROUND LINE OF ENGINE CONTROL MODULE (ECM)">Go to Step 6.

Repair the open circuit of harness between ECM connector and main relay connector.

6.CHECK INPUT VOLTAGE OF ECM.

1) Turn the ignition switch to OFF.

2) Connect the connector to ECM.

3) Turn the ignition switch to ON.

4) Measure the voltage between ECM connector and chassis ground.

Connector & terminal

(B136) No. 6 (+) — Chassis ground (−):

(B137) No. 1 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Check ignition control system. Diagnostics for Engine Starting Failure > IGNITION CONTROL SYSTEM">

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit in harness between ECM connector and main relay connector

• Poor contact of main relay connector

• Poor contact of ECM connector

Diagnostics for engine starting failure

Starter motor circuit

Other materials:

Dtc b1862 short in driver s knee airbag (to ground)
AIRBAG SYSTEM (DIAGNOSTICS) > Diagnostic Chart with Trouble CodeDTC B1862 SHORT IN DRIVER’S KNEE AIRBAG (TO GROUND)Diagnosis start condition:Ignition voltage is 10 V to 16 V.DTC detecting condition:• Airbag main harness circuit is shorted to ground.• Knee airbag module harness c ...

Dtc b2311 rear radar detect tcm
Blind Spot Detection/Rear Cross Traffic Alert (DIAGNOSTICS) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)DTC B2311 REAR RADAR DETECT TCMDTC DETECTING CONDITION:Automatic transmission fails.TROUBLE SYMPTOM:• All functions of BSD/RCTA stop.• Fail icon is displayed in the com ...

Roof antenna (for Rod type)
CAUTION Be sure to remove the antenna rod before entering garages, parking towers and other locations with low ceilings. Remove the antenna rod before washing your car at a car wash. If the antenna rod is left attached, it may scratch the roof. When reinstalling the removed ant ...