Code No. P0328: Detonation Sensor Circuit High Input

OPERATION

A power voltage of 5 V is applied to the detonation sensor terminal from the engine-ECU connector terminal K/S.
The power voltage is earthed to the engine-ECU connector terminal K/SE from the detonation sensor connector terminal.

FUNCTION

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

TROUBLE JUDGEMENT

Check Condition

More than 2 seconds have passed since the engine starting sequence was completed.

Judgement Criteria

Detonation sensor output voltage is more than 2.25 V for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

Fix the ignition timing with an allowance against detonation.

PROBABLE CAUSES

Short circuit in detonation sensor circuit or loose connector contact
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check harness between detonation sensor connector terminal and engine-ECU connector terminal K/SE.

Check earthing line for short circuit.

Q. Is the check result normal?

	Go to Step 2.

	Repair or replace the connector, repair the damaged harness wire.

STEP 2. Check harness between detonation sensor connector terminal and engine-ECU connector terminal K/S.

Check power line for short circuit.

Q. Is the check result normal?

	Go to Step 3.

	Repair the damaged harness wire.

STEP 3. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is diagnosis code stored?

	Replace the engine-ECU.

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