P0500

DTC P0500: Vehicle Speed Sensor

Vehicle Speed Sensor Circuit Part 1:

Vehicle Speed Sensor Circuit Part 2:

CIRCUIT OPERATION
- A 5-volt voltage is applied to the vehicle speed sensor output terminal (terminal No.3) from the ECM (terminal No.80). 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)
- Volume airflow sensor

DTC SET CONDITIONS

Logic Flow Chart:

Logic Flow Chart

Check Conditions
- 2 seconds or more have passed the engine starting sequence was completed.
- Engine speed is at between 2,000 and 4,000 r/min.
- Volumetric efficiency is at between 60 and 80 percent.

Judgment Criterion
- Vehicle speed sensor output voltage has not changed (no pulse signal is input) for 2 seconds.

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 Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B

STEP 1. Using scan tool MB991958, check data list item 24: 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 24, Vehicle Speed Sensor.
- Check that the speedometer and MB991958 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.

NO: Go to Step 2.

STEP 2. Check speedometer.

Q: Is the speedometer functioning?

YES: Go to Step 3.

NO: Go to Step 8.

STEP 3. Using the oscilloscope, check the sensor output voltage at ECM connector C-117.

1. Do not disconnect the ECM connector C-117.
2. Disconnect the combination meter connector and A/C-ECU connector.

3. Connect the oscilloscope probe to ECM terminal No.80 by backprobing.
4. Start the engine.

5. Check the waveform.
- The waveform should show a pattern similar to the illustration while the vehicle is being moved.

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

Q: Is the waveform normal?

YES: Go to Step 4.

NO: Go to Step 6.

STEP 4. Check harness connector C-117 at ECM for damage.

Q: Is the harness connector in good condition?

YES: Go to Step 5.

NO: Repair or replace it. Then go to Step 17.

STEP 5. Using scan tool MB991958, check data list item 24: 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 24, Vehicle Speed Sensor.
- Check that the speedometer and MB991958 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.

NO: Replace the ECM. Then go to Step 17.

STEP 6. Measure the sensor supply voltage at ECM connector C-117 by backprobing.

1. Do not disconnect the ECM connector C-117.
2. Disconnect the vehicle speed sensor connector B-04.
3. Turn the ignition switch to the "ON" position.

4. Measure the voltage between terminal No.80 and ground by backprobing.
- Voltage should be between 4.8 and 5.2 volts.

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

Q: Is the measured voltage between 4.8 and 5.2 volts?

YES: Go to Step 7.

NO: Replace the ECM. Then go to Step 17.

STEP 7. Check harness connector C-117 at ECM for damage.

Q: Is the harness connector in good condition?

YES: Check harness connector B-27 at intermediate connector for damage, and repair or replace as required. If the intermediate connector is in good condition, repair harness wire between vehicle speed sensor connector B-04 (terminal No.3) and ECM connector C-117 (terminal No.80) because of open circuit. Then go to Step 17.

NO: Repair or replace it. Then go to Step 17.

STEP 8. Check harness connector B-04 at vehicle speed sensor for damage.

Q: Is the harness connector in good condition?

YES: Go to Step 9.

NO: Repair or replace it. Then go to Step 17.

STEP 9. Measure the power supply voltage at vehicle speed sensor harness side connector B-04.

1. Disconnect connector B-04 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.

3. Measure the voltage between terminal No.1 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 10.

NO: Check harness connectors C-211, C-210, C-124 and B-27 at intermediate connector for damage, and repair or replace as required. If the intermediate connectors are in good condition, repair the harness wire between ignition switch connector C-208 (terminal No.2) and vehicle speed sensor connector B-04 (terminal No.1) because of open circuit or short circuit to ground. Then go to Step 17.

STEP 10. Check for continuity at vehicle speed sensor harness side connector B-04.

1. Disconnect connector B-04 and measure at the harness side.

2. Check for the continuity between terminal No.2 and ground.
- Should be less than 2 Ohms.

Q: Does continuity exist?

YES: Go to Step 11.

NO: Repair the harness wire between vehicle speed sensor connector B-04 (terminal No.2) and ground because of an open circuit or harness damage. Then go to Step 17.

STEP 11. Measure the sensor supply voltage at vehicle speed sensor harness side connector B-04.

1. Disconnect the vehicle speed sensor connector B-04 and measure at the harness side.
2. Disconnect the combination meter connector and A/C-ECU connector.
3. Turn the ignition switch to the "ON" position.

4. Measure the voltage between terminal No.3 and ground.
- Voltage should be between 4.8 and 5.2 volts.

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

Q: Is the measured voltage between 4.8 and 5.2 volts?

YES: Go to Step 12.

NO: Check connector B-27 at intermediate connector for damage, and repair or replace as the required. If the intermediate connector is in good condition, repair the harness wire between vehicle speed sensor connector B-04 (terminal No.3) and ECM connector C-117 (terminal No.80) because of short circuit to ground or harness damage. Then go to Step 17.

STEP 12. Check the vehicle speed sensor.

Refer to, Combination Meter-Inspection- Vehicle Speed Sensor Check in Vehicle Speed Sensor/testing and inspection.

Q: Is the vehicle speed sensor normal?

YES: Go to Step 13.

NO: Replace the vehicle speed sensor. Then go to Step 17.

STEP 13. Check harness connector C-117 at ECM for damage.

Q: Is the harness connector in good condition?

YES: Go to Step 14.

NO: Repair or replace it. Then go to Step 17.

STEP 14. Check for harness damage between ignition switch connector C-208 (terminal No.2) and vehicle speed sensor connector B-04 (terminal No.1).

NOTE: Check harness after checking intermediate connectors C-211, C-210, C-124 and B-27. If any of the intermediate connectors are damaged, repair or replace them. Then go to Step 17.

Q: Is the harness wire in good condition?

YES: Go to Step 15.

NO: Repair it. Then go to Step 17.

STEP 15. Check for harness damage between vehicle speed sensor connector B-04 (terminal No.3) and ECM connector C-117 (terminal No.80).

NOTE: Check the harness after checking the intermediate connector B-27. If the intermediate connector is damaged, repair or replace it. 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. Check for harness damage between vehicle speed sensor connector B-04 (terminal No.2) and ground.

NOTE: Check the harness after checking the intermediate connector B-27. If the intermediate connector is damaged, repair or replace it. Then go to Step 17.

Q: Is the harness wire in good condition?

YES: Check for harness wire damaged between vehicle speed sensor connector B-04 (terminal No.3) and other system components because of a short circuit to ground. Then go to Step 17.

NO: Repair it. Then go to Step 17.

STEP 17. Using scan tool MB991958, check data list item 24: Vehicle Speed Sensor.

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