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 ABS/EPS module not only if the vehicle speed is low or high but also if the vehicle is or is not moving. Then ABS/ESP module informs ECM of these information. The ECM uses these information 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 ECM 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 ECM 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

Item

Detecting Condition

Possible Cause

DTC Strategy

●

Plausibility check

●

Open or short in harness

●

Poor connection or damaged harness

Enable Conditions

●

Engine speed ＞2112rpm

●

Air mass flow ＞0.44g/rev. (220mg/tdc)

●

No fuel injection shut off

●

Coolant Temp. ＞ 60℃(140℉)

Threshold Value

●

Vehicle speed = 0 with high engine speed and load

Diagnostic Time

●

60 seconds

MIL On Condition

●

2 Driving Cycles

SCHEMATIC DIAGRAM
MONITOR DTC STATUS
1.

Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode

2.

Press F4(DTAL) 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
-

History (Not Present) fault : DTC occurred but has been cleared.

-

Present fault : DTC is occurring at present time.

▶ Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

▶ Go to "Monitor Scan tool Data" procedure

MONITOR SCANTOOL DATA
1.

With vehicle raised on a lift , start the engine and place transaxle in Drive. Let vehicle idle and verify speedometer indicates approx. 10km/h or more(6mph or more) on the instrument cluster.

2.

Connect Scantool and select ABS/ESP system.

3.

Monitor the "WHEEL SPD SENSOR-FR" parameter on the current data list.

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

4.

Is value within the specification?

▶ Wheel speed sensor is OK. Go to Go to "Signal Circuit Inspection" procedure

▶ Check for open or short circuit between wheel speed sensor(FR) and ABS/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:

A.

Gap between wheel speed sensor and trigger wheel (Air gap : 0.3~1.1 mm(0.011 ~ 0.043 in))

B.

Trigger wheel condition

C.

Sensor resistance : Approx. 1,300~1,500Ω at 20℃(68℉)

Replace wheel speed sensor as necessary and go to "Verification of Vehicle Repair" procedure.

SIGNAL CIRCUIT INSPECTION
1.

Check for short to ground in signal circuit

(1)

Ignition "OFF"

(2)

Disconnect ECM and ABS Control Module connectors

(3)

Measure resistance between terminal 53 of the ECM harness connector and chassis ground

Specification : Infinite

(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 battery in signal circuit

(1)

Ignition "ON" ＆ Engine"OFF"

(2)

Measure voltage between terminal 53 of the ECM harness connector and chassis ground

Specification : Approx. 0V

(3)

Is voltage within the specification?

▶ Go to next step as below

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.

3.

Check for open in signal circuit

(1)

Ignition "OFF"

(2)

Measure resistance between terminals 53 of the ECM harness connector and 14 of the ABS Control Module harness connector.

(3)

Measure resistance between terminals 53 of the ECM harness connector and 21 of the ESP Control Module harness connector.

Specification : Approx. 0Ω

(4)

Is resistance within the specification?

▶ Check for poor connection between ECM 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

▶ Go to the applicable troubleshooting procedure.

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