P0327

DTC P0327: Knock Sensor Circuit Low














CIRCUIT OPERATION

- The knock sensor (terminal No. 2) sends a signal voltage to the ECM (terminal No. 25).
- The ground terminal (terminal No. 1) is grounded with ECM (terminal No. 42).

TECHNICAL DESCRIPTION

- The knock sensor converts the vibration of the cylinder block into a voltage and outputs it.
- The ECM checks whether the voltage is within a specified range.

DESCRIPTIONS OF MONITOR METHODS

Knock sensor output voltage is out of specified range.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

- Not applicable
Sensor (The sensor below is determined to be normal)

- Not applicable

DTC SET CONDITIONS

Logic Flow Chart






Check Condition

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

- Knock sensor output voltage is less than 0.5 volt for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

- Fix the ignition timing with an allowance against knock.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 Monitors, Trips, Drive Cycles and Readiness Codes .

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)

- Knock sensor failed.
- Open or shorted knock sensor circuit, harness damage or connector damage.
- ECM failed.

DIAGNOSIS

Required Special Tool:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A

STEP 1. Check harness connector B-116 at knock sensor and harness connector B-108 at ECM for damage.

Q. Are the harness connectors in good condition?

YES Go to Step 2.
NO Repair or replace them. Harness Connector Inspection.
Then go to Step 5.
STEP 2. Check for open circuit and harness damage between knock sensor connector B-116 (terminal No. 1) and ECM connector B-108 (terminal No. 42).

Q. Is the harness wire in good condition?

YES Go to Step 3.
NO Repair it. Then go to Step 5.
STEP 3. Check for open circuit, short circuit to ground and harness damage between knock sensor connector B-116 (terminal No. 2) and ECM connector B-108 (terminal No. 25).

Q. Is the harness wire in good condition?

YES Go to Step 4.
NO Repair it. Then go to Step 5.
STEP 4. Replace the knock sensor.

(1)Replace the knock sensor.

(2)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 Monitors, Trips, Drive Cycles and Readiness Codes.

(3)Check the diagnostic trouble code (DTC).

Q. Is DTC P0327 set?

YES Replace the ECM (Refer to, Removal and Installation Removal and Replacement).
Then go to Step 5.
NO The inspection is complete.
STEP 5. Test the OBD-II drive cycle.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P0327 set?

YES Retry the troubleshooting.
NO The inspection is complete.