AutoCodes – Jeep – P1C99 Jeep

P1C99 Jeep Code - Gear Shift Position Sensor 1 Circuit

Quick Answer

This diagnostic compares the output signal of the sensor to threshold values of normal operations. Common causes include Faulty Gear Shift Position Sensor 1, Gear Shift Position Sensor 1 harness is open or shorted, Gear Shift Position Sensor 1 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: P1C99 Jeep indicates Gear Shift Position Sensor 1 Circuit.
Common causes: Common causes include Faulty Gear Shift Position Sensor 1, Gear Shift Position Sensor 1 harness is open or shorted, Gear Shift Position Sensor 1 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.

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Code Popularity 962

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 12, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1C99 Jeep Description

This diagnostic compares the output signal of the sensor to threshold values of normal operations. When the signal is out of range the diagnostic will be considered failing. The sensor is mounted next to the 1st - 3rd gear engagement actuator to detect a linear movement of the piston. For this purpose, a permanent magnet is mounted on the piston which is moved over a complete travel stroke. The magnet position generates a saturation area in the internal ferromagnetic core of the sensor which is transformed to an output position signal. The sensor provides an output signal with Pulse Width Modulation (PWM) at a fixed frequency and duty cycle proportional to the piston position of the actuator.

OBDII Code P1C99 Jeep - Gear Shift Position Sensor 1 Circuit - AutoCodes.com — P1C99 Jeep Code - Gear Shift Position Sensor 1 Circuit

What does this mean?

What are the Possible Causes of the DTC P1C99 Jeep?

Faulty Gear Shift Position Sensor 1
Gear Shift Position Sensor 1 harness is open or shorted
Gear Shift Position Sensor 1 circuit poor electrical connection
Faulty Transmission Control Module (TCM)

How to Fix the DTC P1C99 Jeep?

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 P1C99 Jeep 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 P1C99 Jeep code?

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Need Help with the Code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P1C99 Jeep Code

1. What are the common symptoms of OBDII code P1C99 in a Jeep related to the Gear Shift Position Sensor 1 Circuit?

The common symptoms include difficulty shifting gears, inaccurate gear display on the dashboard, and potential stalling or inability to start the vehicle.

2. What are the possible causes of the P1C99 fault code on a Jeep's Gear Shift Position Sensor 1 Circuit?

The code may be triggered by a faulty gear shift position sensor, damaged wiring or connectors related to the sensor, or issues with the sensor's calibration.

3. How can I diagnose the Gear Shift Position Sensor 1 Circuit issue causing the P1C99 code on my Jeep?

Diagnosis typically involves checking the sensor's wiring and connectors for damage, testing the sensor's functionality, and verifying the sensor's calibration using diagnostic tools.

4. Can a DIY enthusiast repair the Gear Shift Position Sensor 1 Circuit problem causing the P1C99 code in a Jeep?

While some DIY enthusiasts may be able to replace the gear shift position sensor themselves, proper diagnosis and calibration often require specialized tools and knowledge, so professional help is recommended.

5. What are some tips for repairing the Gear Shift Position Sensor 1 Circuit issue associated with the P1C99 code in a Jeep?

Ensure you use a compatible replacement sensor, follow the manufacturer's instructions for installation, and perform a calibration or relearn procedure if necessary after the repair.

6. Are there any safety concerns associated with driving a Jeep with the P1C99 fault code related to the Gear Shift Position Sensor 1 Circuit?

Driving with this fault code may pose safety risks due to potential shifting issues, inaccurate gear display, or stalling, so it's advisable to address the problem promptly.

7. How much does it typically cost to repair the Gear Shift Position Sensor 1 Circuit problem causing the P1C99 code on a Jeep?

The cost can vary depending on the exact cause of the issue, but it may range from $100 to $300 for parts and labor if a professional mechanic performs the repair.

8. Can resetting the OBDII system clear the P1C99 fault code related to the Gear Shift Position Sensor 1 Circuit in a Jeep?

Resetting the system may temporarily clear the code, but if the underlying issue with the sensor or circuit is not resolved, the code is likely to reappear after driving the vehicle.

9. Will driving with the P1C99 fault code affecting the Gear Shift Position Sensor 1 Circuit damage other vehicle components?

Continued driving with this fault code may lead to further damage to the transmission or related components if the shifting issues are not addressed promptly, so it's best to address the problem as soon as possible.

10. How long does it typically take to repair the Gear Shift Position Sensor 1 Circuit issue causing the P1C99 code on a Jeep?

The repair time can vary depending on the exact cause of the problem and the mechanic's experience, but it may take a few hours to a full day to diagnose, replace the sensor, and perform any necessary calibrations.