P0503

CRUISE CONTROL: CRUISE CONTROL SYSTEM: P0500,P0503: Vehicle Speed Sensor Malfunction

DTC P0500 - Vehicle Speed Sensor Malfunction

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

DESCRIPTION

The cruise control system uses the same vehicle speed signal that is sent to the ECM for the SFI system or the ECD system. If DTC P0500 is detected, perform the diagnosis using the inspection procedure for DTC P0500 in the SFI system P0500 for 2AZ-FE, or P0500 for 2GR-FE). The speed signal is converted for use by the cruise control inside the ECM. Both the SFI system and the cruise control system can set DTC P0500, however, the detection conditions of the two systems are different.






WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: Read freeze frame data using the Techstream or the OBD II scan tool. 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 Freeze Frame Data.

PROCEDURE

1. READ VALUE USING TECHSTREAM (VEHICLE SPEED)
(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.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch on (IG).
(d) Turn the tester on.
(e) Select the following menu items: Powertrain / Engine / Data List / Vehicle Speed.
(f) Drive the vehicle.
(g) Read the value displayed on the tester.
OK:
Vehicle speeds displayed on tester and speedometer display are equal.
OK -- CHECK INTERMITTENT PROBLEMS
NG -- Continue to next step.
2. CHECK COMBINATION METER ASSEMBLY (SPD SIGNAL WAVEFORM)




(a) Inspect the combination meter using an oscilloscope.
(1) Shift the transmission gear selector lever to the neutral position.
(2) Jack up the vehicle.
(3) Turn the ignition switch on (IG).
(4) Measure the voltage between the terminal of the combination meter and 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.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)




(a) Disconnect the F2 combination meter connector.
(b) Disconnect the A55 ECM connector.
(c) Measure the resistance.
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
4. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)




(a) Disconnect the F2 combination meter connector.
(b) Disconnect the A55 ECM connector.
(c) Measure the resistance.
Standard resistance (Check for short):





(d) Reconnect the combination meter connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- GO TO SPEED SIGNAL CIRCUIT