SFI System
2AZ-FE ENGINE CONTROL: SFI SYSTEM: P0500: Vehicle Speed Sensor "A"
P0500 - Vehicle Speed Sensor "A"
DESCRIPTION
The speed sensors detect the wheel speed and send 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 1:
M/T Models, Case 2
M/T Models, Case 2:
A/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 the DTCs (even if no DTCs are stored, perform the clear DTC procedure) DTC Check / Clear.
4. Turn the ignition switch off.
5. Turn the ignition switch to ON and turn the Techstream on [A].
6. Start the engine.
7. Drive the vehicle at 15 mph (24 km/h) or more for a total of 30 seconds or more [B].
8. Stop the vehicle.
9. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
10. Input the DTC: P0500.
11. Check the DTC judgment result [C].
HINT
If the judgment result shows ABNORMAL, the system has a malfunction.
12. If the test result is UNKNOWN, enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
13. Read Pending DTCs.
HINT
If a pending DTC is output, the system is malfunctioning.
14. If the test result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.
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
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. READ VALUE USING TECHSTREAM (VEHICLE SPEED)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(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 tester and speedometer display are equal.
NG -- CHECK HARNESS AND CONNECTOR (ECM - COMBINATION METER)
OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems
2. CHECK HARNESS AND CONNECTOR (ECM - COMBINATION METER)
(a) Disconnect the ECM connector.
(b) Disconnect the combination meter connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
(d) Reconnect the ECM connector.
(e) Reconnect the combination meter connector.
NG -- CHECK HARNESS AND CONNECTOR (ECM - DRIVER SIDE JUNCTION BLOCK)
OK -- Continue to next step.
3. CHECK COMBINATION METER ASSEMBLY (SPD SIGNAL WAVEFORM)
(a) Check the output waveform.
(1) Remove the combination meter assembly with the connector(s) still connected.
(2) Connect an oscilloscope to terminals E46-36 (+S) and body ground.
(3) Turn the ignition switch to ON.
(4) Turn the wheel slowly.
(5) Check the signal waveform according to the condition(s) in the table below.
OK:
The waveform is displayed as shown in the illustration.
HINT
When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.
NG -- GO TO METER / GAUGE SYSTEM Speed Signal Circuit
OK -- REPLACE ECM Components
4. CHECK HARNESS AND CONNECTOR (ECM - DRIVER SIDE JUNCTION BLOCK)
(a) Disconnect the ECM connector.
(b) Disconnect the driver side junction block connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for Open):
(d) Reconnect the ECM connector.
(e) Reconnect the driver side junction block connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - DRIVER SIDE JUNCTION BLOCK)
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE JUNCTION BLOCK)