Code No. P0325: Detonation Sensor System

OPERATION

The sensor signal is input to the engine-ECU <M/T> or engine-A/T-ECU <A/T> (terminal No. 93) from the detonation sensor (terminal No. 2).
The power voltage is earthed to the engine-ECU <M/T> or engine-A/T-ECU <A/T> (terminal No. 103) from the detonation sensor (terminal No. 1).

FUNCTION

The detonation sensor detects the vibration of the cylinder block caused by detonation waves, and inputs a signal to the engine-ECU <M/T> or engine-A/T-ECU <A/T>.
In response to the signal, the engine-ECU <M/T> or engine-A/T-ECU <A/T> provides controls to retard the ignition timing when the detonation occurs.

TROUBLE JUDGMENT

Check Condition

Engine speed is 500 r/min or more.

Judgment Criterion

Detonation sensor output voltage is 0.5 V or lower.

Detonation sensor output voltage is 2.25 V or higher.

PROBABLE CAUSES

Failed detonation sensor
Open/short circuit or harness damage in detonation sensor circuit or loose connector contact
Failed engine-ECU <M/T> or engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-112 detonation sensor connector

Q. Is the check result normal?

	Go to Step 2 .

	Repair or replace the connector.

STEP 2. Perform resistance measurement at B-112 detonation sensor connector.

Disconnect connector and measure at harness side.
Resistance between terminal No. 1 and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

	Go to Step 6 .

	Go to Step 3 .

STEP 3. Connector check: B-112 detonation sensor connector

Q. Is the check result normal?

	Go to Step 4 .

	Repair or replace the connector.

STEP 4. Check harness between B-112 (terminal No. 1) detonation sensor connector and D-246 (terminal No. 103) engine-ECU <M/T> connector or D-217 (terminal No. 103) engine-A/T-ECU <A/T> connector.

note

Before checking harness, check intermediate connector B-103, and repair if necessary.

Check earthing line for open circuit and damage.

Q. Is the check result normal?

	Go to Step 5 .

	Repair the damaged harness wire.

STEP 5. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is diagnosis code set?

	Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 6. Connector check: D-246 engine-ECU <M/T> connector or D-217 engine-A/T-ECU <A/T> connector

Q. Is the check result normal?

	Go to Step 7 .

	Repair or replace the connector.

STEP 7. Check harness between B-112 (terminal No. 2) detonation sensor and D-246 (terminal No. 93) engine-ECU <M/T> connector or D-217 (terminal No. 93) engine-A/T-ECU <A/T> connector.

note

Before checking harness, check intermediate connector B-103, and repair if necessary.

Check output line for open/short circuit and damage.

Q. Is the check result normal?

	Go to Step 8 .

	Repair the damaged harness wire.

STEP 8. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is diagnosis code set?

	Go to Step 9 .

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 9. M.U.T.-III diagnosis code

Reconfirm diagnosis code after replacement of detonation sensor.

Q. Is diagnosis code set?

	Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.

	Check end.