Code No. P0327: Detonation Sensor Circuit Low Input

OPERATION

The sensor signal is input to the engine-ECU connector terminal code K/S from the detonation sensor.
The power voltage is earthed to the engine-ECU connector terminal code K/SE from the detonation sensor.

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 Criterion

Detonation sensor output voltage is less than 0.5 V for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

Fix the ignition timing with an allowance against detonation.

PROBABLE CAUSES

Failed detonation sensor
Open/short circuit or harness damage in detonation sensor circuit or loose connector contact
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Check of open circuit, and damage in K/SE line between detonation sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 2.

	Repair the connector(s) or wiring harness.

STEP 2. Check of open circuit, short circuit, and damage in K/S line between detonation sensor and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector(s) or wiring harness.

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

Reconfirmation of diagnosis code.

Q. Is diagnosis code set?

	Go to Step 4.

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

STEP 4. Replace the detonation sensor

After replacing the detonation sensor, reconfirm whether the diagnosis code is set.

Q. Is the diagnosis code set?

	Replace the engine-ECU.

	Check end.