Engine Control System - SFI System

2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0500: Vehicle Speed Sensor "A"
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 stores the DTC.

Manual Transaxle Models:

The ECM assumes that the vehicle is being driven when the fuel-cut operation* is being executed. If there is no speed signal, despite the conditions being met, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and stores 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

A/T Models

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON and turn the Techstream on.

3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the Techstream on [A].

6. Start the engine and warm it up until the ECT reaches 75°C (167°F) or higher [B].

7. Accelerate the vehicle to 74 km/h (46 mph) or higher [C].

8. Maintain the vehicle speed at 74 km/h (46 mph) or higher for 10 seconds or more [D].

9. Decelerate the vehicle by releasing the accelerator pedal for 5 seconds or more to perform fuel cut [E].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws

10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [F].

11. Read pending DTCs.

HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.

12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

13. Input the DTC: P0500.

14. Check the DTC judgment result.

HINT
If the judgment result shows ABNORMAL, the system has a malfunction.

15. If the result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT
- Various systems use the vehicle speed signal distributed from the combination meter. Check all the components possibly related to speed signal.
- Read freeze frame data using the 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.

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 Speedometer Malfunction
OK -- Continue to next step.

2. READ VALUE USING TECHSTREAM (VEHICLE SPEED)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Data List / Vehicle Speed.

(e) Drive the vehicle.

(f) Read the value displayed on the Techstream.

OK:

Vehicle speeds displayed on the Techstream and speedometer display are equal.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)

OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems

3. 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 Short):

HINT
If the wire has a short, check the speed signal circuit in other systems related to the vehicle speed signal (e.g. tire pressure warning system, audio system, etc.).

(d) Reconnect the combination meter connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (OTHER SYSTEMS RELATED TO SPEED SIGNAL)
OK -- Continue to next step.

4. CHECK COMBINATION METER (+S VOLTAGE)

(a) Disconnect the combination meter connector.

HINT
Disconnect the ECU connectors on the other systems related to the speed signal (but the ECM connectors must be connected).

(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Text in Illustration

(d) Reconnect the combination meter connector.

NG -- REPLACE ECM Removal
OK -- Continue to next step.

5. CHECK COMBINATION METER (SPD SIGNAL OUTPUT 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:

Text in Illustration

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 -- CHECK COMBINATION METER (SPD SIGNAL INPUT WAVEFORM)

OK -- REPLACE ECM Removal

6. CHECK COMBINATION METER (SPD SIGNAL INPUT WAVEFORM)

Text in Illustration

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 -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE ACTUATOR)

OK -- REPLACE COMBINATION METER Removal

7. CHECK HARNESS AND CONNECTOR (COMBINATION METER - BRAKE ACTUATOR)

(a) Disconnect the combination meter connector.

(b) Disconnect the brake actuator connector.

(c) Measure the resistance according the value(s) in the table below.

Standard Resistance (Check for Open):

Standard Resistance (Check for Short):

(d) Reconnect the combination meter connector.

(e) Reconnect the brake actuator connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal