Engine Control System: SFI System

2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0500: Vehicle Speed Sensor "A"

DTC P0500 - Vehicle Speed Sensor "A"

DTC P0503 - Vehicle Speed Sensor "A" Intermittent / Erratic / High

DESCRIPTION

Vehicles, which are equipped with ABS (Anti-Lock Brake System), detect the vehicle speed using the skid control ECU and wheel speed sensor. The wheel speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU. The skid control ECU converts the wheel speed signal into a 4-pulse signal and transmits it to the ECM via the combination meter. The ECM determines the vehicle speed based on the frequency of the pulse signal.









MONITOR DESCRIPTION

The ECM assumes that the vehicle is driven when the park/neutral position switch is OFF and it has been over 4 seconds since the actual vehicle speed was 6 mph (9 km/h) or more.
If there is no signal from the vehicle speed sensor when these conditions are satisfied, the ECM concludes that there is a fault in the vehicle speed sensor. The ECM will turn on the MIL and a DTC is set.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT: Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE

1. CHECK OPERATION OF SPEEDOMETER
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON and turn the tester ON.
(c) Start the engine.
(d) Enter the following menu: Powertrain / Engine and ECT / Data List / All Data / Vehicle Speed.
(e) Read the vehicle speed on the tester.
Result:





B -- CHECK SPEEDOMETER CIRCUIT (COMBINATION METER)
A -- Continue to next step.

2. INSPECT ECM (SPD VOLTAGE)
(a) Move the shift lever to the neutral position.
(b) Jack up the vehicle.
(c) Turn the ignition switch ON.




(d) Measure the voltage between the specified terminals of the E6 and E7 ECM connectors as the wheel is turned slowly.
Standard:





HINT: The output voltage should fluctuate up and down similarly to the diagram when the wheel is turned slowly.

NG -- CHECK AND REPAIR HARNESS AND CONNECTOR BETWEEN COMBINATION METER AND ECM
OK -- REPLACE ECM