P0708 2018 GMC Sierra Code - Transmission Range Switch Circuit High Voltage
Quick Answer
The P0708 diagnostic trouble code (DTC) specifically pertains to the Transmission Range Switch Circuit High Voltage on a 2018 GMC Sierra. Common causes include Faulty transmission range switch, Wiring or connector issues in the transmission range switch circuit, Corrosion or damage to the transmission range switch. 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
- P0708 2018 GMC Sierra indicates Transmission Range Switch Circuit High Voltage.
- Common causes
- Common causes include Faulty transmission range switch, Wiring or connector issues in the transmission range switch circuit, Corrosion or damage to the transmission range switch.
- 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.
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Code P0708 2018 GMC Sierra Description
The P0708 diagnostic trouble code (DTC) specifically pertains to the Transmission Range Switch Circuit High Voltage on a 2018 GMC Sierra. This code indicates that there is a high voltage condition detected in the transmission range switch circuit. The transmission range switch, also known as the neutral safety switch, is responsible for indicating the gear position of the transmission to the engine control module (ECM). It ensures that the vehicle can only be started in Park or Neutral and that the proper gear is selected for driving.
Common Causes of P0708 2018 GMC Sierra
- Faulty transmission range switch
- Wiring or connector issues in the transmission range switch circuit
- Corrosion or damage to the transmission range switch
- ECM software or hardware issues
- Electrical system malfunctions
Symptoms of P0708 2018 GMC Sierra
- Difficulty starting the vehicle
- Incorrect gear selection
- Harsh shifting or transmission slipping
- Illumination of the Check Engine Light
- Vehicle goes into limp mode
How to Fix P0708 2018 GMC Sierra
- Diagnose the issue by using a scan tool to retrieve the DTC and inspect the transmission range switch circuit for any visible damage.
- Test the transmission range switch using a multimeter to determine if it is sending the correct voltage signals.
- Replace the transmission range switch if it is found to be faulty, ensuring proper alignment and connection.
- Inspect and repair any damaged wiring or connectors in the transmission range switch circuit.
- Clear the DTC from the ECM memory and test drive the vehicle to ensure the issue has been resolved.
Cost to Fix P0708 2018 GMC Sierra
The cost of repairing the P0708 code on a 2018 GMC Sierra can vary depending on the extent of the issue and the labor rates in your area. On average, the cost of replacing a transmission range switch can range from $150 to $300, including parts and labor. Additional costs may apply if there are wiring or connector issues that need to be addressed. It is recommended to consult with a professional mechanic to get an accurate estimate for your specific situation. Keep in mind that labor rates at auto repair shops can vary, so it's advisable to shop around for the best price.
Tech Notes for P0708 2018 GMC Sierra
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Frequently Asked Questions about P0708 2018 GMC Sierra Code
1. What does the OBDII code P0708 mean on a 2018 GMC Sierra?
P0708 indicates a high voltage issue in the transmission range switch circuit, which monitors the gear selector position.
2. What are the common symptoms of the P0708 code on a 2018 GMC Sierra?
Symptoms may include the transmission being stuck in one gear, erratic shifting, a check engine light, or the vehicle entering limp mode.
3. What causes the P0708 code to appear on a 2018 GMC Sierra?
Common causes include a faulty transmission range sensor, damaged wiring or connectors, or issues with the powertrain control module (PCM).
4. Can I drive my 2018 GMC Sierra with the P0708 code?
It is not recommended to drive with this code as it may lead to further transmission damage or unsafe driving conditions.
5. How do I diagnose the P0708 code on a 2018 GMC Sierra?
Start by inspecting the transmission range sensor, checking for damaged or corroded wiring, and using a diagnostic scanner to monitor sensor voltage.
6. How do I fix the P0708 code on a 2018 GMC Sierra?
Repairs may involve replacing the transmission range sensor, repairing damaged wiring, cleaning connectors, or reprogramming the PCM if necessary.
7. How much does it cost to fix the P0708 code on a 2018 GMC Sierra?
The repair cost varies, but replacing the transmission range sensor typically costs $200–$400, including parts and labor.
8. Can a faulty battery cause the P0708 code on a 2018 GMC Sierra?
A weak or faulty battery can sometimes cause voltage-related issues, but it is less likely to directly trigger the P0708 code.
9. Does the P0708 code mean my transmission is failing on my 2018 GMC Sierra?
Not necessarily. The issue is often electrical, such as a faulty sensor or wiring, rather than a mechanical failure of the transmission.
10. Will clearing the P0708 code fix the problem on a 2018 GMC Sierra?
Clearing the code may temporarily turn off the check engine light, but the underlying issue must be resolved to prevent the code from returning.
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