SFI System

2GR-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

The ECM assumes that the vehicle is being driven when the transmission counter gear indicates more than 300 rpm and over 30 seconds have passed since the park / neutral position switch was turned OFF. If there is no signal from the vehicle speed sensor with these conditions satisfied, the ECM concludes that the vehicle speed sensor is malfunctioning. The ECM will turn on the MIL and a DTC will be 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 HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)




(a) Disconnect the combination meter connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to 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 ECM connector.
NG -- CHECK HARNESS AND CONNECTOR (ECM - JUNCTION CONNECTOR)
OK -- Continue to next step.
2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)




(a) Remove the combination meter.
(b) Connect the oscilloscope to terminal E1-9(+S) and body ground.
(c) Turn the ignition switch on (IG).
(d) Turn the wheel slowly.
(e) 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
OK -- REPLACE ECM
3. CHECK HARNESS AND CONNECTOR (ECM - JUNCTION CONNECTOR)




(a) Disconnect the ECM connector.
(b) Disconnect the junction connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:





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