Engine Control System - SFI System

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

DTC P0500 - Vehicle Speed Sensor "A"

DESCRIPTION

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. The skid control ECU converts these wheel speed signals into a 4-pulse signal and outputs it to the ECM via the combination meter. The ECM determines the vehicle speed based on the frequency of these pulse signals.









MONITOR DESCRIPTION

Automatic Transaxle Models:
The ECM assumes that the vehicle is being driven when the vehicle speed sensor signal is being transmitted by the combination meter. If there is no signal from the combination meter, despite the ECM detecting the speed signal from the speed sensor NC, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and sets the DTC.
Manual Transaxle Models:
The ECM assumes that the vehicle is being driven when the indicated engine speed is more than 2,000 rpm and the engine load calculated by the ECM is more than a certain level or the idle fuel-cut operation* is being executed. If there is no signal from the vehicle speed sensor, despite these conditions being met, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and sets the DTC.
*: Idle fuel-cut is executed when the throttle valve is fully closed and engine speed is over 2800 rpm.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

M/T Models, Case 1





M/T Models, Case 2





A/T Models





TYPICAL MALFUNCTION THRESHOLDS





WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: Read freeze frame data using a Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1. CHECK OPERATION OF SPEEDOMETER
(a) Drive the vehicle and check whether the operation of the speedometer in the combination meter is normal.
OK:
The operation of the speedometer is normal.
HINT:
- The vehicle speed sensor is operating normally if the speedometer reading is normal.
- If the speedometer does not operate, check it by following the procedure described in Speedometer Malfunction .

NG -- GO TO MALFUNCTION IN SPEEDOMETER
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (VEHICLE SPEED)
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester ON.
(d) Select the following menu items: Powertrain / Engine and ECT / Data List / All Data / Vehicle Speed.
(e) Drive the vehicle.
(f) Read the value displayed on the tester.
OK:
Vehicle speeds displayed on tester and speedometer display are equal.
NG -- CHECK COMBINATION METER (+S VOLTAGE)
OK -- CHECK FOR INTERMITTENT PROBLEMS
3. CHECK COMBINATION METER (+S VOLTAGE)





(a) Disconnect the combination meter connector.
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





(d) Reconnect the combination meter connector.
NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)
OK -- Continue to next step.
4. CHECK COMBINATION METER (SPD SIGNAL WAVEFORM)





(a) Remove the combination meter.
(b) Connect the combination meter connector.
(c) Move the shift lever to the neutral position.
(d) Jack up the vehicle.
(e) Turn the ignition switch to ON.
(f) Check the voltage between the terminal of the combination meter and the body ground while the wheel is turned slowly.
Standard voltage:





HINT: The output voltage should fluctuate up and down, similarly to the diagram, when the wheel is turned slowly.
(g) Reinstall the combination meter.
NG -- REPLACE COMBINATION METER
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)





(a) Disconnect the combination meter connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according the value(s) in the table below.
Standard resistance (Check for open):






Standard resistance (Check for open):





(d) Reconnect the combination meter connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM