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.
DTP 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.
DTP DETDCING CONDITION
ITEM
DETECING CONDITION
POSSIBLE CAUSE
Case1)
DTC Strategy
● Plausibility check
● Open or short in harness
● Contact resistance in connectors
● Faulty wheel speed sensor
Enable Conditions
● Engine speed ＞2100 rpm
● Engine load ＞250 mg/rev.
● Coolant temperature ＞ 60℃(140℉)
● 10V< Battery voltage ＜16V
● No fuel shut-off
Threshold Value
● Vehicle speed=0 with high engine speed and engine load
Diagnostic Time
● 60 seconds
Case2)
DTC Strategy
● Electrical check
Enable Conditions
● Vehicle speed ＞ 0
● 10V＜ Battery voltage ＜16V
Threshold Value
● PCM detects abnormal input voltage of the signal circuit
Diagnostic Time
● 10 seconds
SCHEMATIC DIGRAM
SIGNAL CIRCUIT INSPECTION
[WITH ABS]
1.
Check for open in circuit.
(1)
Ignition "OFF".
(2)
Disconnect PCM and ABS or ESP Control Module connectors.
(3)
Measure resistance between terminals 39 of the PCM harness connector and 3 of the ABS Control Module harness connector(W/ABS)
Measure resistance between terminals 39 of the PCM harness connector and 5 of the ESP Control Module harness connector(W/ESP)
Specification : Approx. 0Ω
(4)
Is resistance within the specification?
▶ Go to next step as below.
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
2.
Check for short to ground in circuit.
(1)
Measure resistance between terminal 39 of the PCM harness connector and chassis ground.
Specification : Infinite
(2)
Is resistance within the specification?
▶ 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.
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
[EUROPE & WITHOUT ABS SYSTEM]
1.
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. 0Ω
[W/O 4WD]
- Terminal 1(sensor) & Terminal 17(PCM)
- Terminal 2(sensor) & Terminal 18(PCM)
[WITH 4WD]
- Terminal 3(sensor) & Terminal 17(PCM)
- Terminal 4(sensor) & Terminal 18(PCM)
(4)
Is resistance within the specification.
▶ Go to next step as below.
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
2.
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?
▶ 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.
▶ 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 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
