P0325
DTC P0325 KNOCK SENSOR 1 CIRCUITComponent Location:
COMPONENT LOCATION
GENERAL DESCRIPTION
Knocking is a phenomenon characterized by undesirable vibration and noise and can cause engine damage. The knock sensor (KS) is attached to the cylinder block and senses engine knocking. A knocking vibration from the cylinder block is applied as pressure to the piezoelectric element. The Knock Sensor (KS) detects vibration upon increase and decrease in engine RPM and generates a voltage based on this vibration. The PCM controls the ignition timing based on the amplitude and frequency of the knock sensor signal. For example, if engine knocking occurs, the ignition timing is retarded to suppress it.
DTC DESCRIPTION
If there is rarely change compared with previous knock sensor's signal, the PCM determines that a fault exists.
DTC Detecting Condition:
Schematic Diagram:
TERMINAL & 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?
YES: Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Go to " Signal Circuit Inspection " procedure.
SIGNAL CIRCUIT INSPECTION
1. Check for short to ground in harness
1. Ignition "OFF"
2. Disconnect IG failure sensor connector.
3. Measure resistance between terminal 1 of knock sensor harness connector and chassis ground.
Specification: Infinite
4. Is the measured resistance within specifications?
YES: Go to "Check for short to battery in harness" as below.
NO:
- Check short to ground in signal harness.
- Repair or replace as necessary and then, go to " Verification of Vehicle Repair" procedure.
2. Check for short to battery in harness
1. Ignition "OFF"
2. Disconnect knock sensor connector.
3. Ignition "ON" & Engine "OFF"
4. Measure voltage between terminal 1 of knock sensor harness connector and chassis ground.
Specification: Approx. 0 V
5. Is the measured voltage within specification?
YES: Go to "Check for open in harness" as below.
NO:
- Check for short to battery in harness.
- Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
3. Check for open in harness
1. Ignition "OFF"
2. Disconnect knock sensor connector and PCM connector.
3. Measure resistance between terminal 1 of knock sensor harness connector and terminal 20 / C44-3 of PCM harness connector.
Specification: Approx. below 1 Ohms
4. Is the measured resistance within specifications?
YES: Go to "Ground Circuit Inspection" procedure.
NO:
- Check for open in harness.
- Repair or replace as necessary. And then, go to "Verification of Vehicle Repair" procedure.
GROUND CIRCUIT INSPECTION
1. Check for open in harness
1. Ignition "OFF"
2. Disconnect Knock sensor connector.
3. Measure voltage between terminal 2 of knock sensor harness connector and chassis ground.
Specification: Approx. below 1 Ohms
4. Is the measured resistance within specifications?
YES:
- Substitute with a known - good knock sensor and check for proper operation.
- If the problem is corrected, replace knock sensor and go to "Verification of Vehicle Repair" procedure.
NO:
- Check for open in harness.
- Repair or replace as necessary. And then, go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all readiness tests have been verified as "Complete"
5. Are any DTCs present?
YES: Go to the applicable troubleshooting procedure.
NO: System is performing to specification at this time.