P0500

DTC P0500: Vehicle Speed Sensor Malfunction [M/T]






















CIRCUIT OPERATION

- A 5-volt voltage is applied to the vehicle speed sensor output terminal (terminal No. 2) from the ECM (terminal No. 109). The vehicle speed sensor generates a pulse signal when the output terminal is opened and grounded.

TECHNICAL DESCRIPTION

- The vehicle speed sensor converts the vehicle speed into pulse signals and inputs them to the ECM.
- The vehicle speed sensor outputs a pulse signal while the vehicle is driven.
- The ECM checks whether the pulse signal is output.

DESCRIPTIONS OF MONITOR METHODS

- If the vehicle speed sensor output does not change while the vehicle is being driven in the medium- to high-speed range, a malfunction is determined to have occurred.

MONITOR EXECUTION

- Continuous

MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

- Not applicable
Sensor (The sensor below is determined to be normal)

- Mass airflow sensor

DTC SET CONDITIONS (Entry Conditions and Malfunction Thresholds)

Logic Flow Chart






Check Conditions

- More than 2 seconds have passed since the engine starting sequence was completed.
- Engine speed is between 2,000 and 4,000 r/min.
- Volumetric efficiency is between 40 and 65 percent.
Judgement Criterion

- Vehicle speed sensor output voltage does not change (no pulse signal is input) for 2 seconds.

FAIL-SAFE AND BACKUP FUNCTION

- None

OBD-II DRIVE CYCLE PATTERN

None

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )

- Vehicle speed sensor failed.
- Open or shorted vehicle speed sensor circuit, harness damage or connector damage.
- ECM failed.

DIAGNOSIS

Required Special Tool:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A

STEP 1. Using scan tool MB991958, check data list item 4: Vehicle Speed Sensor.





CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

(1)Connect scan tool MB991958 to the data link connector.
(2)Start the engine.
(3)Set scan tool MB991958 to the data reading mode for item 4, Vehicle Speed Sensor.

- Check that the speedometer and M.U.T.-III display speed match when traveling at a vehicle speed of 40 km/h (25 mph).
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the sensor operating properly?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.

NO Go to Step 2.

STEP 2. Check harness connector B-111 at vehicle speed sensor for damage.

Q. Is the harness connector in good condition?

YES Go to Step 3.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 17.
STEP 3. Measure the power supply voltage at vehicle speed sensor harness side connector B-111.

(1)Disconnect the connector B-111 and measure at the harness side.

(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal No. 3 and ground.

- Voltage should be battery positive voltage.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is battery positive voltage (approximately 12 volts) present?

YES Go to Step 5.

NO Go to Step 4.

STEP 4. Check harness connector A-30X at MFI relay for damage.

Q. Is the harness connector in good condition?

YES Check harness connector A-10 at intermediate connector for damage, and repair or replace as required. Harness Connector Inspection.
If intermediate connector is in good condition, repair harness wire between MFI relay connector A-30X (terminal No. 2) and vehicle speed sensor connector B-111 (terminal No. 3) because of open circuit or short circuit to ground. Then go to Step 17.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 17.
STEP 5. Check the continuity at vehicle speed sensor harness side connector B-111.

(1)Disconnect the connector B-111 and measure at the harness side.





(2)Check for the continuity between terminal No. 1 and ground.

- Continuity (2 ohms or less)

Q. Does the continuity exist?

YES Go to Step 8.

NO Go to Step 6.

STEP 6. Check harness connector B-109 at ECM for damage.

Q. Is the harness connector in good condition?

YES Go to Step 7.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 17.
STEP 7. Check for open circuit and harness damage between vehicle speed sensor connector B-111 (terminal No. 1) and ECM connector B-109 (terminal No. 110).

NOTE:
Check harness after checking intermediate connector A-10. If intermediate connector is damaged, repair or replace it. Harness Connector Inspection.
Then go to Step 17.

Q. Is the harness wire in good condition?

YES Go to Step 11.
NO Repair it. Then go to Step 17.
STEP 8. Measure the sensor supply voltage at vehicle speed sensor harness side connector B-111.

(1)Disconnect the connector B-111 and measure at the harness side.

(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal No. 2 and ground.

- Voltage should be between 4.9 and 5.1 volts.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the measured voltage between 4.9 and 5.1 volts?

YES Go to Step 12.

NO Go to Step 9.

STEP 9. Check harness connector B-109 at ECM for damage.

Q. Is the harness connector in good condition?

YES Go to Step 10.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 17.
STEP 10. Check for open circuit and short circuit to ground between vehicle speed sensor connector B-111 (terminal No. 2) and ECM connector B-109 (terminal No. 109).

NOTE:
Check harness after checking intermediate connector A-10. If intermediate connector is damaged, repair or replace it. Harness Connector Inspection.
Then go to Step 17.

Q. Is the harness wire in good condition?

YES Go to Step 11.
NO Repair it. Then go to Step 17.
STEP 11. Using scan tool MB991958, check data list item 4: Vehicle Speed Sensor.

(1)Start the engine.

(2)Set scan tool MB991958 to the data reading mode for item 4, Vehicle Speed Sensor.

- Check that the speedometer and M.U.T.-III display speed match when traveling at a vehicle speed of 40 km/h (25 mph).

(3)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the sensor operating properly?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
NO Replace the ECM (Refer to, Removal and Installation Removal and Replacement).
Then go to Step 17.
STEP 12. Check harness connector A-30X at MFI relay for damage.

Q. Is the harness connector in good condition?

YES Go to Step 13.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 17.
STEP 13. Check for harness damage between MFI relay connector A-30X (terminal No. 2) and vehicle speed sensor connector B-109 (terminal No. 3).

NOTE:
Check harness after checking intermediate connector A-10. If intermediate connector is damaged, repair or replace it. Harness Connector Inspection.
Then go to Step 17.

Q. Is the harness wire in good condition?

YES Go to Step 14.
NO Repair it. Then go to Step 17.
STEP 14. Check harness connector B-109 at ECM for damage.

Q. Is the harness connector in good condition?

YES Go to Step 15.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 17.
STEP 15. Check for harness damage between vehicle speed sensor connector B-111 (terminal No. 2) and ECM connector B-109 (terminal No. 109).

NOTE:
Check harness after checking intermediate connector A-10. If intermediate connector is damaged, repair or replace it. Harness Connector Inspection.
Then go to Step 17.

Q. Is the harness wire in good condition?

YES Go to Step 16.
NO Repair it. Then go to Step 17.
STEP 16. Replace the vehicle speed sensor.

(1)Replace the vehicle speed sensor.

(2)Turn the ignition switch to the "ON" position.

(3)Ease the DTC.

(4)Test drive under the following conditions:

- Engine speed: 2,000 - 4,000 r/min
- Engine load: 40 - 65 %

(5)After completing the test drive, read the DTC. Turn the ignition switch to the
"LOCK" (OFF) position.

Q. Is DTC P0500 set?

YES Replace the ECM (Refer to, Removal and Installation Removal and Replacement.) Then go to Step 17.
NO The inspection is complete.
STEP 17. Using scan tool MB991958, read the diagnostic trouble code
(DTC).

(1)Turn the ignition switch to the "ON" position.

(2)Erase the DTC.

(3)Test drive under the following conditions:

- Engine speed: 2,000 - 4,000 r/min
- Engine load: 40 - 65 %

(4)After completing the test drive, read the DTC.Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is DTC P0500 set?

YES Retry the troubleshooting.
NO The inspection is complete.