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 ECM not only if the vehicle speed is low or high but also if the vehicle is or is not moving. The ECM 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
Checking output signals from wheel speed sensor or ABS control unit or VSS every 30 sec. under detecting condition, if an signal is in the detecting condition for more than 20 sec., PCM sets P0501. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till cosecutive 2 driving cycle.
DTC DETECTING CONDITION
SIGNAL WAVEFORM AND DATA
SCHEMATIC DIAGRAM
[Without ABS/ESC]
[With ABS (or ESC)]
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"?
YES
> Go to "Terminal and connector inspection" procedure.
NO
> 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.
[With ABS/ESC]
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 short to ground in harness
(1) IG "OFF"
(2) Disconnect PCM connector and ABS or ESP control module connector.
(3) Measure resistance between terminal C201-1 (52) of PCM harness connector and chassis ground.
Specification : Infinite
(4) Is the measured resistance within specifications?
YES
> Go to "Check open in harness" as follows.
NO
> Repair short to ground in harness, and go to "Verification of Vehicle Repair" procedure.
2. Check for open in harness
(1) Ignition "OFF"
(2) Disconnect PCM connector and ABS or ESP control module connector.
(3) Measure resistance between terminal C201-1 (52) of PCM harness connector and terminal "C04(3) (With ESP: terminal C03(6))" of ABS control module harness connector.
Specification : Approx. below 1Ohms
NOTE:
Note: This picture is only applied to vehicle with ABS/ESC
(4) Is the measured resistance within specifications?
YES
> Go to " Check wheel speed sensor " procedure.
NO
> Check open in harenss.
> Repair or replace as necessary and then, go to " Verification of Vehicle Repair" procedure.
3. Check wheel speed sensor
(1) IG "OFF"
(2) Check open or short in wheel speed sensor
(3) Is the wheel speed sensor normal?
YES
> Substitute with a known - good PCM/ ABS or ESP control unit and check for proper operation. If the problem is corrected, replace PCM/ ABS or ESP control unit and go to "Verification of Vehicle Repair" procedure.
NO
> Repair or replace it as necessary.
> And then 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
[Without ABS/ESC]
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 " Power Circuit Inspection " procedure.
SIGNAL CIRCUIT INSPECTION
1. Check resistance between circuits.
(1) IG "OFF"
(2) Disconnect wheel speed sensor connector and PCM connector.
(3) Measure resistance between terminal 1 and 2 of wheel speed sensor harness connector.
Specification : Infinite
(4) Is the measured resistance within specifications?
YES
> Go to "Check voltage" procedure.
NO
> Repair short in harness, and go to "Verification of Vehicle Repair" procedure.
2. Check voltage
(1) IG "OFF"
(2) Disconnect vehicle speed sensor connector.
(3) IG "ON" and ENG "OFF"
(4) Measure voltage between terminal 1,2 of wheel speed sensor harness connector and chassis ground.
(5) Is the measured voltage terminal 0V or 12V?
Approx. 0V
> Go to "Check resistance between WSS and PCM" as follows.
Approx. 12V
> Repair short to power in harness, and go to "Verification of Vehicle Repair" procedure.
3. Check resistance between WSS and PCM
(1) IG "OFF"
(2) Disconnect PCM connector and vehicle speed sensor connector.
(3) Measure resistance between terminal C201-1(79) of PCM harness connector and terminal 1 of wheel speed sensor harness connector.
(4) Measure resistance between terminal C201-1(80) of PCM harness connector and terminal 2 of wheel speed sensor harness connector.
Specification: Approx. below 1Ohms
(5) Is the measured resistance within specifications?
YES
> Go to " Ground circuit inspection " procedure.
NO
> Check open in harenss.
> Repair or replace as necessary and then, go to " Verification of Vehicle Repair" procedure.
4. Check resistance between WSS and ground
(1) IG "OFF"
(2) Disconnect vehicle speed sensor connector and PCM connector.
(3) Measure resistance between terminal 1 of wheel speed sensor harness connector and chassis ground.
(4) Measure resistance between terminal 2 of wheel speed sensor harness connector and chassis ground.
Specification : Infinite
(5) Is the measured resistance within specifications?
YES
> Substitute with a known - good wheel speed sensor and check for proper operation. If the problem is not correctd, substitute with a known - good PCM and check for proper operation. And go to "Verification of Vehicle Repair" procedure.
NO
> Repair short to contact resistance 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
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 rediness test have been verified as " Complete "
5. Are any DTCs present ?
YES
> Go to the applicable troubleshoooting procedure.
NO
> System is performing to specification at this time.