COMPONENT LOCATION
GENERAL DESCRIPTION

The knock sensor is attached to the cylinder block and senses engine knocking. The sensor contains a piezoelectric element that converts vibration (or noise) into voltage signal and sends this signal to ECM. With input signals from camshaft position and crankshaft position sensor, ECM can identify which cylinder is knocking. ECM filters vibrations and determines if the vibrations are knocking signal. The Engine Control Module (ECM) uses this signal to suppress knocking by retarding ignition timing. The ECM will set a code (Malfunction Indicator Lamp will Not turn on) if during two driving cycles the Knock sensor’s output voltage falls below minimum threshold. This code indicates an unexpected vibration is being read by the Knock sensor or ECM under normal engine operation.

DTC DESCRIPTION

Checking the range of input signal with a knock sensor under detecting condition, PCM senses short in knock sensor circuit or malfunction of sensor. If the average value of the knok signals is out of the threshold value during standard duration, PCM sets P0326.

DTC DETECTING CONDITION

Item

Detecting Condition

Possible cause

DTC Strategy

●

Signal short

●

Poor connection

●

Short in harness

●

Knock sensor

●

PCM

Enable Conditions

●

Pressure in intake manifold is normal.

●

Engine speed ≥ 2000 rpm

Threshold value

●

Knock Filtered Value 〈 5 or 〉 65

Diagnosis Time

●

Continuous

MIL On Condition

●

No MIL ON (DTC only)

SIGNAL WAVEFROM AND DATE
SCHEMATIC DIAGRAM
MONITOR DTC STATUS
1.

Check DTC Status

(1)

Connect scantool to Data Link Connector(DLC).

(2)

IG "ON".

(3)

Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC's information from the DTCs menu

(4)

Read "DTC Status" parameter.

(5)

Is parameter displayed "Present fault"?

▶ Go to "Terminal and connector inspection" procedure.

▶ Fault is intermittent caused by poor contact in the sensor’s and/or PCM’s connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

TERMINAL AND CONNECTOR INSPECTION
1.

Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

3.

Has a problem been found?

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure

▶ Go to "Signal Circuit Inspection" procedure.

SIGNAL CIRCUIT INSPECTION
1.

Check short to battery in harness

(1)

IG "OFF" and disconnect knock sensor connector.

(2)

IG "ON" and ENG "OFF"

(3)

Measure voltage between terminal 1 of knock sensor harness connector and chassis ground.

(4)

Measure voltage between terminal 2 of knock sensor harness connector and chassis ground.

Specification : Approx. 1.5V

(5)

Is the measured voltage within specification?

▶ Go to "Check short to ground in harness" as follows.

▶ Repair short to battery in harness, and go to "Verification of Vehicle Repair" procedure.

2.

Check short to ground in harness

(1)

IG "OFF" and disconnect knock sensor connector and PCM connector.

(2)

Measure resistance between terminal 1 of knock sensor harness connector and chassis ground.

(3)

Measure resistance between terminal 2 of knock sensor harness connector and chassis ground.

(4)

Measure resistance between terminal 1 and 3 of knock sensor harness connector.

(5)

Measure resistance between terminal 2 and 3 of knock sensor harness connector.

Specification : Infinite

(6)

Is the measured resistance within specification?

▶ If the problem is corrected after substituting with a known - good knock sensor, replace it. If the problem is pending, check for proper operating after substituting with a known - good PCM. and then if the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.

▶ Repair short to ground in harness, and go to "Verification of Vehicle Repair" procedure.

note

There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM. After testing PCM on the vehicle, use this function to reuse the PCM on the others

VERIFICATION OF VEHICLE REPAIR
1.

Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode

2.

Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions

3.

Read "DTC Status" parameter

4.

Is parameter displayed "History(Not Present) fault"?

▶ System performing to specification at this time. Clear the DTC.

▶ Go to the applicable troubleshooting procedure.

Яндекс.Метрика