P18B8 2017 GMC Sierra Code - Internal Mode Switch 'P' Circuit Shorted
Quick Answer
The internal mode switch indicates the Transmission Control Module (TCM) which gear position the vehicle operator has selected. Common causes include Faulty Transmission Internal Mode Switch, Transmission Internal Mode Switch harness is open or shorted, Transmission Internal Mode Switch 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
- P18B8 2017 GMC Sierra indicates Internal Mode Switch 'P' Circuit Shorted.
- Common causes
- Common causes include Faulty Transmission Internal Mode Switch, Transmission Internal Mode Switch harness is open or shorted, Transmission Internal Mode Switch 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 P18B8 2017 GMC Sierra Description
What are the Possible Causes of the DTC P18B8 2017 GMC Sierra?
- Faulty Transmission Internal Mode Switch
- Transmission Internal Mode Switch harness is open or shorted
- Transmission Internal Mode Switch circuit poor electrical connection
- Faulty Transmission Control Module (TCM)
How to Fix the DTC P18B8 2017 GMC Sierra?
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 P18B8 2017 GMC Sierra 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.
Need more information about the P18B8 2017 GMC Sierra code?
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Frequently Asked Questions about P18B8 2017 GMC Sierra Code
What does the OBDII code P18B8 mean for a 2017 GMC Sierra?
The code P18B8 indicates an issue with the Internal Mode Switch 'P' Circuit, specifically a shorted condition in the circuit.
What are common symptoms of the P18B8 code in a GMC Sierra?
Common symptoms include difficulty shifting into Park, the transmission failing to recognize the Park position, or the vehicle not starting properly.
What causes the P18B8 code to appear?
The code is typically triggered by wiring issues, such as a short circuit, damaged connectors, or a faulty internal mode switch within the transmission.
Can the P18B8 code affect drivability?
Yes, it can affect drivability by preventing the vehicle from shifting into Park properly, which may compromise safety and functionality.
How is the P18B8 code diagnosed?
A mechanic will use a scan tool to read the code, inspect the wiring and connectors for damage, and test the internal mode switch for proper operation.
Can I drive with the P18B8 code active?
It is not recommended, as issues with the Park circuit can pose safety risks, such as the inability to secure the vehicle when parked.
What repairs are typically needed for the P18B8 code?
Repairs may include replacing damaged wiring, repairing connectors, or replacing the internal mode switch if it is malfunctioning.
How much does it cost to fix the P18B8 code on a GMC Sierra?
Repair costs vary but can range from $150 to $500 depending on the extent of the damage and whether parts like the internal mode switch need replacement.
Is the P18B8 code related to the transmission control module?
While the code primarily concerns the internal mode switch, issues with the transmission control module or its communication may also contribute.
Can a low battery or electrical issue cause the P18B8 code?
Yes, electrical issues like low voltage or a weak battery can potentially cause communication errors, leading to the P18B8 code.
Discuss the causes and fixes for P18B8 2017 GMC Sierra OBDII Code
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