AutoCodes – Cadillac – P1871 Cadillac

P1871 Cadillac Code - Undefined Gear Ratio

Quick Answer

P1871 Cadillac indicates Undefined Gear Ratio. Common causes for P1871 Cadillac include wiring or connector problems, a faulty related sensor or actuator, and control module or calibration issues. 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: P1871 Cadillac indicates Undefined Gear Ratio.
Common causes: Common causes for P1871 Cadillac include wiring or connector problems, a faulty related sensor or actuator, and control module or calibration issues.
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 3,437

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Sep 25, 2019

Description
How To Fix
Cost to Diagnose
FAQs
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Code P1871 Cadillac Description

OBDII Code P1871 Cadillac - Undefined Gear Ratio - AutoCodes.com — P1871 Cadillac Code - Undefined Gear Ratio

How to Fix the DTC P1871 Cadillac?

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 P1871 Cadillac 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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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 P1871 Cadillac Code

1. What are the common symptoms of OBDII code P1871 Cadillac (Undefined Gear Ratio)?

- Common symptoms include harsh shifting, slipping transmission, and difficulty engaging gears.

2. What are the possible causes of OBDII code P1871 Cadillac?

- Potential causes include low transmission fluid levels, a faulty transmission control module, worn-out clutch components, or mechanical issues within the transmission.

3. How can I diagnose OBDII code P1871 Cadillac?

- Diagnosing this code typically involves using a scan tool to retrieve the code and checking the transmission fluid level and condition. A professional mechanic may also perform further tests to pinpoint the exact cause.

4. Can I continue driving with OBDII code P1871 Cadillac active?

- It is not recommended to drive with this code active, as it can lead to further damage to the transmission and potentially unsafe driving conditions.

5. How can I repair OBDII code P1871 Cadillac?

- Repair options may include topping up or replacing the transmission fluid, repairing or replacing faulty clutch components, or addressing any mechanical issues within the transmission.

6. Is it safe to reset the OBDII code P1871 Cadillac without fixing the underlying issue?

- Resetting the code without addressing the root cause can temporarily clear the warning light, but the issue will likely resurface. It is best to diagnose and repair the problem to prevent further damage.

7. Can a DIY enthusiast fix OBDII code P1871 Cadillac at home?

- While some basic checks like inspecting the transmission fluid can be done at home, diagnosing and repairing the underlying issues of this code often require professional knowledge and tools.

8. How much does it cost to repair OBDII code P1871 Cadillac?

- The cost of repairing this code can vary depending on the exact cause of the issue, the extent of the damage, and the labor rates of the repair shop. It is best to get a diagnostic assessment for an accurate estimate.

9. Will OBDII code P1871 Cadillac cause my vehicle to fail an emissions test?

- Yes, an active OBDII code like P1871 Cadillac can cause your vehicle to fail an emissions test due to potential transmission issues affecting performance and emissions output.

10. How can I prevent OBDII code P1871 Cadillac from occurring in the future?

- Regular maintenance of your vehicle, including checking and changing transmission fluid as recommended, can help prevent issues that may trigger OBDII code P1871 Cadillac.