Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSSUBARU2005OUTBACK I, STANDARDREPAIR AND DIAGNOSISENGINE PERFORMANCETESTING & DIAGNOSISENGINE CONTROLS - ENGINE (DIAGNOSTICS) (H4SO)DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)DTC P0328 KNOCK SENSOR 1 CIRCUIT HIGH INPUT (BANK 1 OR SINGLE SENSOR)

2005 Subaru Outback i, Standard

DTC P0328 Knock Sensor 1 Circuit High Input (Bank 1 Or Single Sensor)

2005 Subaru Outback i, StandardSECTION DTC P0328 Knock Sensor 1 Circuit High Input (Bank 1 Or Single Sensor)

DTC DETECTING CONDITION:

Detect as soon as malfunction occurs.
GENERAL DESCRIPTION < Ref. to DTC P0328 KNOCK SENSOR 1 CIRCUIT HIGH INPUT (BANK 1 OR SINGLE SENSOR) , Diagnostic Trouble Code (DTC) Detecting Criteria. >

TROUBLE SYMPTOM:

Poor driving performance
Knocking occurs.

CAUTION: After repair or replacement of faulty parts, conduct Clear Memory Mode < Ref. to , OPERATION , Clear Memory Mode.> and Inspection Mode < Ref. to , PROCEDURE , Inspection Mode.>.

WIRING DIAGRAM:

Fig 1: DTC P0328 Knock Sensor 1 Circuit High Input (Bank 1 Or Single Sensor)

Courtesy of SUBARU OF AMERICA, INC.

DTC P0328 KNOCK SENSOR 1 CIRCUIT HIGH INPUT (BANK 1 OR SINGLE SENSOR) DIAGNOSIS

Step

Check

Yes

1. CHECK HARNESS BETWEEN KNOCK SENSOR AND ECM CONNECTOR.

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

Connector & terminal

(B136) No. 25 - Chassis ground:

Is the resistance less than 400 kΩ?

Go to step 2.

Go to step 3.

2. CHECK KNOCK SENSOR.

Disconnect the connector from knock sensor.
Measure the resistance between knock sensor connector terminal and engine ground.
Terminals

No. 2 - Engine ground:

Is the resistance less than 400 kΩ?

Replace the knock sensor. < Ref. to KNOCK SENSOR . >

Repair ground short circuit in harness between knock sensor connector and ECM connector.

NOTE: The harness between both connectors shielded. Repair short circuit of harness together with shield.

3. CHECK INPUT SIGNAL FOR ECM.

Connect the connectors to ECM and knock sensor.
Turn the ignition switch to ON.
Measure the voltage between ECM and chassis ground.
Connector & terminal

(B136) No. 25 (+) - Chassis ground (-):

Is the voltage more than 2 V?

Even if malfunction indicator light lights up, the circuit has returned to a normal condition at this time. (However, the possibility of poor contact still remains.)

NOTE: In this case, repair the following:

Poor contact in knock sensor connector
Poor contact in ECM connector
Poor contact in coupling connector

Repair poor contact in ECM connector.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.