C1278 Toyota Code - Abnormal Change in Output Signal of Rear Speed Sensor Left
Quick Answer
The speed sensor detects the wheel speed and sends the appropriate signals to the Skid Control ECU (Brake Actuator Assembly). Common causes include Faulty Rear Speed Sensor Left, Rear Speed Sensor Left Rotor (Rear Axle Hub and Bearing Assembly Left), Rear Speed Sensor Left harness is open or shorted. 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
- C1278 Toyota indicates Abnormal Change in Output Signal of Rear Speed Sensor Left.
- Common causes
- Common causes include Faulty Rear Speed Sensor Left, Rear Speed Sensor Left Rotor (Rear Axle Hub and Bearing Assembly Left), Rear Speed Sensor Left harness is open or shorted.
- 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 C1278 Toyota Description
What are the Possible Causes of the DTC C1278 Toyota?
- Faulty Rear Speed Sensor Left
- Rear Speed Sensor Left Rotor (Rear Axle Hub and Bearing Assembly Left)
- Rear Speed Sensor Left harness is open or shorted
- Rear Speed Sensor Left circuit poor electrical connection
How to Fix the DTC C1278 Toyota?
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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the C1278 Toyota 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 Toyota Models
- C1278 2013 Toyota RAV4 — Abnormal Change in Output Signal of Rear Speed Sensor Left
- C1278 2014 Toyota RAV4 — Abnormal Change in Output Signal of Rear Speed Sensor Left
- C1278 2015 Toyota RAV4 — Abnormal Change in Output Signal of Rear Speed Sensor Left
- C1278 2016 Toyota RAV4 — Abnormal Change in Output Signal of Rear Speed Sensor Left
- C1278 2017 Toyota RAV4 — Abnormal Change in Output Signal of Rear Speed Sensor Left
- C1278 2018 Toyota RAV4 — Abnormal Change in Output Signal of Rear Speed Sensor Left
Frequently Asked Questions about C1278 Toyota Code
1. What are the common symptoms of OBDII code C1278 in a Toyota related to the abnormal change in output signal of the rear speed sensor left?
- Common symptoms include erratic speedometer readings, ABS warning light illuminated on the dashboard, and possible traction control issues.
2. What could be the potential causes of OBDII code C1278 in a Toyota?
- The code could be triggered by a faulty rear speed sensor on the left side, damaged wiring or connectors, or a malfunction in the ABS control module.
3. How can I diagnose the issue causing OBDII code C1278 in my Toyota?
- Start by inspecting the rear speed sensor on the left side for any visible damage or corrosion. Check the wiring and connectors for any signs of wear or disconnection. Use a diagnostic scanner to retrieve specific error codes and data related to the issue.
4. Can I drive my Toyota with OBDII code C1278 until I can get it repaired?
- It is not recommended to drive the vehicle with this code present, as it may affect the accurate functioning of the ABS system, traction control, and overall vehicle stability.
5. What are the repair options for fixing OBDII code C1278 in a Toyota?
- Repair options include replacing the rear speed sensor on the left side, repairing or replacing damaged wiring or connectors, or addressing any issues with the ABS control module.
6. Are there any DIY tips for resolving OBDII code C1278 in a Toyota?
- DIY tips include checking and cleaning the connectors, inspecting the wiring for any visible damage, and ensuring proper installation of a new rear speed sensor if needed.
7. How much does it typically cost to repair OBDII code C1278 in a Toyota at a dealership or repair shop?
- The cost can vary depending on the specific cause of the issue, but it may range from $100 to $500 or more for parts and labor.
8. Will resetting the OBDII code C1278 in my Toyota make the issue go away permanently?
- Resetting the code may temporarily clear the warning light, but if the underlying issue is not fixed, the code is likely to reappear once the system detects the problem again.
9. Can extreme weather conditions or rough driving terrain trigger OBDII code C1278 in a Toyota?
- Yes, extreme weather conditions or driving on rough terrain can potentially damage the rear speed sensor or wiring, leading to the abnormal output signal detected by the system.
10. How critical is it to address OBDII code C1278 promptly in a Toyota?
- It is crucial to address this code promptly as it directly impacts the functionality of important safety systems like ABS and traction control, which are essential for vehicle stability and braking performance.
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