Without ABS

Fuel System - Troubleshooting - P0501

Component Location:

GENERAL DESCRIPTION
The Wheel Speed Sensor (WSS) generates a waveform with a frequency proportional to the speed of the vehicle. The signal generated by the WSS informs the PCM not only if the vehicle speed is low or high but also if the vehicle is or is not moving. The PCM uses this signal to control the fuel injection, ignition timing, transaxle shift scheduling and torque converter clutch scheduling. The WSS signal is also used to detect rough road conditions.

DTC DESCRIPTION
The PCM evaluates engine speed and mass air flow if there is no vehicle speed signal. This evaluation of both values will detect open circuit or short circuit errors on the wheel speed sensor. The PCM sets DTC P0501 if there is no vehicle speed signal from wheel speed sensor while both engine speed and mass air flow are higher than predetermined threshold during the predetermined time.

DTC Detecting Condition:

MONITOR DTC STATUS
1. Connect Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Press F5(INFO) to select DTC information from the DTCs menu.
3. Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Read "DTC Status" parameter.
5. Is parameter displayed "History(Not Present) fault"?

NOTE:
1. History (Not Present) fault : DTC occurred but has been cleared.
2. Present fault : DTC is occurring at present time.

YES - 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, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

NO
- [With ABS] Go to "Monitor Scan tool Data" procedure.
- [Without ABS system] Go to "Signal Circuit Inspection[Without ABS]" procedure.

MONITOR SCAN TOOL DATA
1. With vehicle raised on a lift, start the engine and place transaxle in Drive. Let vehicle idle and verify speedometer indicates approx. 10 km/h or more(6 mph or more) on the instrument cluster.
2. Connect Scantool and select ABS system.
3. Monitor the "WHEEL SPD SENSOR-FR" parameter on the current data list.

Specification : 10 km/h or more(6 mph or more)

4. Is value within the specification?

YES - Wheel speed sensor is OK. Go to "Signal Circuit Inspection[With ABS]" procedure.

NO
- Check for open or short circuit between wheel speed sensor(FR) and ABS(or ESP) control module.
- If problems are found, repair as necessary and go to "Verification of Vehicle Repair" procedure
- If OK, Check wheel speed sensor(FR) as follow :
- Gap between ABS sensor and trigger wheel (Air gap : 0.3 - 1.1 mm (0.011 - 0.043 in))
- Trigger wheel condition - Sensor resistance : Approx. 1,300 - 1,500 Ohms at 20 degrees C (68 degrees F)
- Replace wheel speed sensor as necessary and go to "Verification of Vehicle Repair" procedure.

SIGNAL CIRCUIT INSPECTION

[WITHOUT ABS SYSTEM]




3. Check for open in circuit.
1. Ignition "OFF".
2. Disconnect PCM and wheel speed sensor(front right) harness connector.
3. Measure resistance between wheel speed sensor harness connector and PCM harness connector.

Specification : Approx. 0 Ohm

- Terminal 1(sensor) & Terminal 17(PCM)
- Terminal 2(sensor) & Terminal 18(PCM)

4. Is resistance within the specification.

YES - Go to next step.

NO - Repair as necessary and go to "Verification of Vehicle Repair" procedure.




4. Check for short to ground in circuit.
1. Measure resistance between terminal 17 of the PCM harness connector and chassis ground.
2. Measure resistance between terminal 18 of the PCM harness connector and chassis ground.

Specification : Infinite

3. Is resistance within the specification?

YES - Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure.

NO - Repair as necessary and 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. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Press F5(INFO) 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"?

YES - System performing to specification at this time. Clear the DTC

NO - Go to the applicable troubleshooting procedure.

Schematic Diagram: