P0503
CRUISE CONTROL SYSTEM: P0500/21: Vehicle Speed Sensor "A"
DTC P0500/21 - Vehicle Speed Sensor "A"
DTC P0503/23 - 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. If DTC P0500 is detected, perform the diagnosis using the inspection procedure for DTC P0500 in the SFI system (Engine Control System - SFI System) for 2AZ-FE, or (Engine Control System - SFI System) for 3MZ-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.
2AZ-FE ENGINE:
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Read freeze frame data using 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 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" (Speedometer Malfunction).
NG -- GO TO SPEEDOMETER MALFUNCTION
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (VEHICLE SPD)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester on.
(d) Select the following menu items: Powertrain / Engine and ECT / Data List / 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.
OK -- CHECK FOR INTERMITTENT PROBLEMS
NG -- Continue to next step.
3. CHECK COMBINATION METER ASSEMBLY (+S VOLTAGE)
(a) Disconnect the combination meter connector.
(b) Turn the ignition switch to the ON position.
(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 ASSEMBLY - ECM)
OK -- Continue to next step.
4. CHECK COMBINATION METER ASSEMBLY (SPD SIGNAL WAVEFORM)
(a) Shift the transmission gear selector lever to the neutral position.
(b) Jack up the vehicle.
(c) Turn the ignition switch to the ON position.
(d) Measure the voltage between the terminal of the combination meter and body ground while the wheels are turned slowly.
Standard voltage:
HINT: The output voltage should fluctuate up and down, similarly to the diagram, when the wheels are turned slowly.
NG -- REPLACE COMBINATION METER ASSEMBLY
OK -- Continue to next step.
5. 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 -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM
3MZ-FE ENGINE:
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Read freeze frame data using 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 OPERATION OF SPEEDOMETER
(a) Drive the vehicle and check if the operation of the speedometer in the combination meter is normal.
OK:
Actual vehicle speed and the speed indicated on the speedometer are the same.
HINT:
- The vehicle speed sensor is operating normally if the speedometer reading is normal.
- The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart (On-Vehicle inspection).
NG -- CHECK SPEEDOMETER CIRCUIT
OK -- Continue to next step.
2. INSPECT ECM (SPD VOLTAGE)
(a) Shift the shift lever to the N position.
(b) Jack up the vehicle.
(c) Turn the ignition switch to the ON position.
(d) Check the voltage between the terminals of the ECM connectors as the wheel is turned slowly.
OK:
HINT: The output voltage should fluctuate up and down similarly to the diagram on the left when the wheel is turned slowly.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM