P0502 Code - Vehicle Speed Sensor 'A' Low Input
Quick Answer
The vehicle speed sensor outputs a 4 pulse signal for every revolution of the rotor shaft, which is rotated by the transmission output shaft via the driven gear. Common causes include Faulty Vehicle Speed Sensor, Vehicle speed sensor harness or connectors is open or shorted, Vehicle speed sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0502 indicates Vehicle Speed Sensor 'A' Low Input.
- Common causes
- Common causes include Faulty Vehicle Speed Sensor, Vehicle speed sensor harness or connectors is open or shorted, Vehicle speed sensor circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0502 Description
What are the Possible Causes of the DTC P0502?
- Faulty Vehicle Speed Sensor
- Vehicle speed sensor harness or connectors is open or shorted
- Vehicle speed sensor circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0502?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0502 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Makes
- P0502 Acura — CVT Speed Sensor Circuit Open/Short
- P0502 Buick — Vehicle Speed Sensor Circuit Low Input
- P0502 Cadillac — Vehicle Speed Sensor Circuit Low Input
- P0502 Chevrolet — Vehicle Speed Sensor Circuit Low Input
- P0502 Ford — Vehicle Speed Sensor 'A' Low Input
- P0502 GMC — Vehicle Speed Sensor Circuit Low Input
- P0502 Honda — CVT Speed Sensor Circuit Open/Short
- P0502 Isuzu — Vehicle Speed Sensor 'A' Low Input
- P0502 Mercedes-Benz — Vehicle Speed Sensor 'A' Low Input
- P0502 Pontiac — Vehicle Speed Sensor Circuit Low Input
- P0502 Saturn — Vehicle Speed Sensor Circuit Low Input
- P0502 Subaru — Vehicle Speed Sensor 'A' Low Input
Frequently Asked Questions about P0502 Code
1. What are the common symptoms of OBDII code P0502 (Vehicle Speed Sensor 'A' Low Input)?
- Common symptoms include erratic speedometer readings, issues with cruise control functionality, and the activation of the Check Engine Light.
2. What are the possible causes of OBDII code P0502?
- The code P0502 can be triggered by a faulty vehicle speed sensor, damaged or corroded wiring, a defective speedometer, or issues with the vehicle's transmission.
3. How does the vehicle speed sensor contribute to the operation of a vehicle?
- The vehicle speed sensor plays a crucial role in providing input to various systems in the vehicle, such as the speedometer, cruise control, and the transmission control module.
4. Can a faulty vehicle speed sensor impact the overall performance of the vehicle?
- Yes, a faulty vehicle speed sensor can lead to inaccurate speed readings, affecting the operation of the speedometer, cruise control, and transmission shifting.
5. What are some diagnostic steps to troubleshoot OBDII code P0502?
- Diagnostic steps may include checking the vehicle speed sensor for proper operation, inspecting the wiring for any damage, testing the speedometer functionality, and scanning the vehicle's computer for error codes.
6. Is it safe to continue driving with OBDII code P0502 present?
- It is generally not recommended to drive with OBDII code P0502 present, as it can lead to inaccurate speed readings and potentially affect the vehicle's performance and safety features.
7. How can OBDII code P0502 be repaired?
- Repairing OBDII code P0502 may involve replacing the faulty vehicle speed sensor, repairing damaged wiring, recalibrating the speedometer, or addressing any underlying transmission issues.
8. Can OBDII code P0502 be triggered intermittently?
- Yes, OBDII code P0502 can sometimes be triggered intermittently, especially if the issue is related to a loose connection or intermittent fault in the vehicle speed sensor system.
9. Will resetting the Check Engine Light resolve OBDII code P0502?
- Resetting the Check Engine Light may temporarily clear the code, but it will likely reappear if the underlying issue causing OBDII code P0502 is not addressed.
10. Can a DIY enthusiast repair OBDII code P0502 at home?
- Depending on the specific cause of OBDII code P0502, some DIY enthusiasts with automotive repair experience may be able to diagnose and repair the issue at home, especially if it involves simple tasks like sensor replacement or wiring checks. However, more complex issues may require professional diagnosis and repair.
Discuss the causes and fixes for P0502 OBDII Code
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P0502 code Wheel speed sensor...replaced both and still hasn't fixed the problem!?? What next...took the ECM out and cleaned (looks fine) cleaned ground...
2002 Chevy Suburban 2500, 8.1
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Actually the P0502 code is for the Vehicle Speed Sensor, you should have replaced the sensor on the transmission instead.
P0502 Chevrolet - Vehicle Speed Sensor Circuit Low Input
Read more: https://www.autocodes.com/p05...
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we replaced 3 VSS and have a new code for the Wheel speed sensor. Should be located on top of the Dif? Its not! Where is it?
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I'm Having a problem with mine too.I replaced the vss and still no change....thinking maybe the wiring harness????My ABS,Brake light,& service airbag light is on & my speedometer isn't working
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What make, model and year is your vehicle? If you have already replaced the sensors and you still have the same code, then is is a big chance that the problem is the wire harness.
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where can I get just the wiring harness since I just put the new sensor in I don't want to have buy another???
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I also have O2 sensor codes popping up.... could they be related somehow?
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I found a wiremissing on the O2 sensor plug so I rewired it....which resulted in no change what so ever...where do I go from here?
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my speedometer will not work right a way then abs light comes on and transmission will not shift after driving for a while speedometer starts to work abs light goes out then i have to stop and shut the truck off and start it again and then it works fine tell i am stopped for a while it is a 1999 gmc sonoma I did find a code P0502 what could it be? Would the speed sensor have anything to do with the abs?
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Yes, the speed sensor is more than likely the problem. The speed sensor will affect the transmission, speedometer and ABS.
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After 5 failed smog tests...OBDII "not ready"...after being told to "just drive your car"...I need help! Everything else is OK.
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What components test are not completing? What model and year is your vehicle?
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Have a Frontera B 3.2L AT 4x4 Year 2000. The speedometer dosen´t work. Get the code P0502. I have change the speedometer on the shaft. Still no speed signal on instrument or on the OBD unit. May it take the signal from the gear speed sensor on the transmission as well. Where dose the signal go? Dose it go to the ECM?
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Maybe i have to explain... changed the sensor just after the transmission art. nr 897129727 haven´t change the sensor just in front of the rear axel art. nr 96014422
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2002 GrandAM GT, with the 4T45E. Over a bump, the speedo goes nuts, the trans wont shift right, slams into gear. Fixes itself and everything is fine again. Previous owner replaced the VSS and had some wiring done after the speedo died and the P0502 code registered. I have no codes at all, suspect a bad ground for the VSS??
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