| DTC Code | DTC Name |
|---|---|
| P050031 | Vehicle Speed Sensor "A" No Signal |
DESCRIPTION
Vehicles, which are equipped with ABS (Anti-lock Brake System), detect the vehicle speed using the skid control ECU (brake actuator assembly) and speed sensor. The speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU. The skid control ECU converts the wheel speed signal into a 4-pulse signal and transmits it to the ECM via the combination meter assembly. The ECM determines the vehicle speed based on the frequency of the pulse signal.
Tech Tips
Various systems use the vehicle speed signal distributed from the combination meter. Check all the components possibly related to speed signal.
A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly.
The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls the respective system based on the pulse signal.
If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems using the speed signal will not operate normally.
| *a | 4-Pulse |
| *b | Skid Control ECU |
| *c | From Speed Sensor |
| *d | Combination Meter Assembly |
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory | Note |
|---|---|---|---|---|---|---|
| P050031 | Vehicle Speed Sensor "A" No Signal | While vehicle being driven, no vehicle speed sensor signal transmitted to ECM (2 trip detection logic). |
|
Comes on | DTC stored | SAE: P0500 |
MONITOR DESCRIPTION
If there is no speed signal from the combination meter assembly even though the ECM determines that the vehicle is being driven, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and stores the DTC.
MONITOR STRATEGY
| Required Sensors/Components (Main) | Vehicle speed sensor Combination meter Skid control ECU |
| Required Sensors/Components (Related) | Park/neutral position switch Engine coolant temperature sensor Crankshaft position sensor Speed Sensor NC Throttle position sensor Mass air flow meter sub-assembly |
| Frequency of Operation | Continuous |
TYPICAL ENABLING CONDITIONS
| Transaxle counter gear revolution | 300 rpm or higher |
CONFIRMATION DRIVING PATTERN
| *1 | 24 km/h |
| *2 | Idling |
| *3 | Engine Switch on (IG) |
| *4 | Total of 30 seconds or more |
Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) and turn the GTS on [A].
Start the engine.
Drive the vehicle at 24 km/h (15 mph) or more for a total of 30 seconds or more [B].
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Stop the vehicle.
Enter the following menus: Powertrain / Engine / Trouble Codes [C].
Read the pending DTCs.
Tech Tips
If a pending DTC is output, the system is malfunctioning.
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P050031.
Check the DTC judgment result.
| GTS Display | Description |
|---|---|
| NORMAL |
|
| ABNORMAL |
|
| INCOMPLETE |
|
| N/A |
|
Tech Tips
If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
WIRING DIAGRAM
| *1 | Combination Meter Assembly |
| *2 | from Skid Control ECU |
CAUTION / NOTICE / HINT
Tech Tips
Read freeze frame data using the GTS. 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
READ VALUE USING GTS (VEHICLE SPEED)
Connect the GTS to the DLC3.
Turn the engine switch on (IG) and turn the GTS on.
Enter the following menus: Powertrain / Engine / Data List / Vehicle Speed.
| Tester Display |
|---|
| Vehicle Speed |
Drive the vehicle.
Read the value displayed on the GTS.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
CHECK FOR INTERMITTENT PROBLEMS Click here |
| A |
|
CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)
Disconnect the combination meter assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - JUNCTION CONNECTOR) |
| OK |
|
CHECK COMBINATION METER SYSTEM
Check the circuits that send vehicle speed signals to this system in the combination meter system.
| Result | ||
|---|---|---|
|
| NEXT |
|
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Clear the DTCs.
Turn the engine switch off and wait for at least 30 seconds.
Start the engine.
Turn the GTS on.
Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
Enter the following menus: Powertrain / Engine / Trouble Codes.
Tech Tips
If no DTCs (no pending DTCs) are output to the GTS, the repair has been successfully completed.
| Result | ||
|---|---|---|
|
| NEXT |
|
END |