M20F-FXS, M20G-FXS ENGINE CONTROL SFI SYSTEM P032511 Knock Sensor 1 Bank 1 or Single Sensor Circuit Short to Ground
DESCRIPTION
A flat-type knock sensor (non-resonant type) has a structure that can detect vibrations between approximately 5 and 15 kHz.
The knock sensor is fitted onto the engine block to detect engine knocking.
The knock sensor contains a piezoelectric element which generates a voltage when it becomes deformed.
The voltage is generated when the engine block vibrates due to knocking. Any occurrence of engine knocking can be suppressed by delaying the ignition timing.
- HINT:
-
When DTC P032511 is stored, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is delayed to its maximum retardation. Fail-safe mode continues until the ignition switch is off.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Note |
|---|---|---|---|---|---|
| P032511 | Knock Sensor 1 Bank 1 or Single Sensor Circuit Short to Ground | The knock sensor output voltage is less than 0.5 V for 1 second or more (1 trip detection logic). | ·
Short in knock sensor circuit ·
Knock sensor ·
ECM |
Comes on | SAE Code: P0327 |
Reference: Inspection using an oscilloscope
- HINT:
-
The correct waveform is as shown.
| ECM Terminal Name | Between KNK1 and EKNK |
| Tester Range | 1 V/DIV., 1 ms./DIV. |
| Condition | Engine speed maintained at 2500 rpm after warming up engine |
MONITOR DESCRIPTION
If the output voltage transmitted by the knock sensor remains low for 1 second or more, the ECM interprets this as a malfunction in the sensor circuit, illuminates the MIL and stores this DTC.
MONITOR STRATEGY
| Frequency of Operation | Continuous |
CONFIRMATION DRIVING PATTERN
- HINT:
- ·
After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
·When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON.
Turn the GTS on.
Put the engine in Inspection Mode (Maintenance Mode).
Start the engine and wait 5 minutes [A].
Enter the following menus: Powertrain / Engine / Trouble Codes [B].
Read the pending DTCs.
- HINT:
- ·
If a pending DTC is output, the system is malfunctioning.
·If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P032511.
Check the DTC judgment result.
| GTS Display | Description |
|---|---|
| NORMAL | ·
DTC judgment completed ·
System normal |
| ABNORMAL | ·
DTC judgment completed ·
System abnormal |
| INCOMPLETE | ·
DTC judgment not completed ·
Perform driving pattern after confirming DTC enabling conditions |
- HINT:
- ·
If the judgment result is NORMAL, the system is normal.
·If the judgment result is ABNORMAL, the system is malfunctioning.
·If the judgment result is INCOMPLETE, idle the engine for 5 minutes and check the DTC judgment result again.
·[A] to [B]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
·When clearing the permanent DTCs, do not disconnect the cable from the auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
- NOTICE:
- ·
Vehicle Control History may be stored in the hybrid vehicle control ECU assembly if the engine is malfunctioning. Certain vehicle condition information is recorded when Vehicle Control History is stored. Reading the vehicle conditions recorded in both the Freeze Frame Data and Vehicle Control History can be useful for troubleshooting.
(Select Powertrain in Health Check and then check the time stamp data.)
·If any "Engine Malfunction" Vehicle Control History item has been stored in the hybrid vehicle control ECU assembly, make sure to clear it. However, as all Vehicle Control History items are cleared simultaneously, if any Vehicle Control History items other than "Engine Malfunction" are stored, make sure to perform any troubleshooting for them before clearing Vehicle Control History.
- HINT:
-
Read Freeze Frame Data using the GTS. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. When troubleshooting, Freeze Frame Data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
| *a | Front view of wire harness connector
(to Knock Sensor) |
Disconnect the knock sensor connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection Condition Specified Condition Z1-2 - Z1-1 Ignition switch ON 4.5 to 5.5 V
- Result:
Proceed to OK NG
OK
NG
- HINT:
-
Perform "Inspection After Repair" after replacing the knock sensor.
- Result:
Proceed to OK NG
OK
NG
Disconnect the knock sensor connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection Condition Specified Condition Z1-2 or C141-111 (KNK1) - Body ground Always 10 kΩ or higher
- Result:
Proceed to OK NG
OK
NG
Clear the DTCs.
- Powertrain > Engine > Clear DTCs
- 50002 372
Turn the ignition switch off and wait for at least 30 seconds.
- Result:
Proceed to NEXT
NEXT
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Read the DTCs.
- Powertrain > Engine > Trouble Codes
- 50001 372
- Result:
Result Proceed to DTCs are not output A DTC P032511 is output B
A
B