AutoCodes – Generic – P189C

P189C Code - Transmission Range Command Message Performance

Quick Answer

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission Control Module 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: P189C indicates Transmission Range Command Message Performance.
Common causes: Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission Control Module 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 1,680

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 Sep 29, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P189C Description

Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Operating information and commands are exchanged among the control modules. Each module on the serial data circuit maintains a transmit error counter and a receive error counter. The counter values increase with detected errors and decrease with error-free messages. The Diagnostic Trouble Code (DTC) will be set when the Transmission Range Command Message Performance.

OBDII Code P189C - Transmission Range Command Message Performance - AutoCodes.com — P189C Code - Transmission Range Command Message Performance

What does this mean?

What are the Possible Causes of the DTC P189C?

Faulty Transmission Control Module (TCM)
Transmission Control Module harness is open or shorted
Transmission Control Module circuit poor electrical connection

How to Fix the DTC P189C?

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 P189C 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 P189C code?

Need more information on how to fix the P189C code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P189C code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P189C Buick — Transmission Range Command Message Performance
P189C Cadillac — Transmission Range Command Message Performance
P189C Chevrolet — Transmission Range Command Message Performance
P189C GMC — Transmission Range Command Message Performance

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 P189C Code

1. What are the common symptoms of OBDII code P189C (Transmission Range Command Message Performance)?

- Common symptoms include difficulty shifting gears, delayed gear engagement, and potential loss of transmission functionality.

2. What are the possible causes of OBDII code P189C?

- Possible causes can include a faulty transmission range sensor, issues with the transmission control module (TCM), wiring problems, or a software malfunction.

3. How can I diagnose the cause of OBDII code P189C?

- Diagnosis typically involves using a professional OBDII scanner to retrieve the code, checking the transmission range sensor for proper operation, inspecting wiring connections, and performing a TCM scan for any related issues.

4. Is it safe to continue driving with OBDII code P189C present?

- It is not recommended to continue driving with this code present, as it can lead to further transmission damage and potential safety hazards.

5. What are the repair options for fixing OBDII code P189C?

- Repair options may include replacing the transmission range sensor, repairing any damaged wiring, reprogramming the TCM, or seeking assistance from a qualified mechanic for further diagnosis and repair.

6. Can a DIY enthusiast fix OBDII code P189C at home?

- While some repairs related to this code may be possible for experienced DIY enthusiasts, it is recommended to consult a professional mechanic for accurate diagnosis and repair to ensure the issue is properly resolved.

7. How much can I expect to pay to fix OBDII code P189C?

- The cost of fixing this code can vary depending on the specific cause of the issue, but it may range from a few hundred to a few thousand dollars, including parts and labor.

8. Will resetting the OBDII code P189C turn off the check engine light?

- Resetting the code may temporarily turn off the check engine light, but if the underlying issue is not addressed, the code is likely to reappear, and the light will come back on.

9. Are there any preventative maintenance tips to avoid OBDII code P189C in the future?

- Regularly checking and maintaining the transmission system, including fluid levels and condition, can help prevent issues that may trigger OBDII code P189C.

10. Can OBDII code P189C cause permanent damage to the transmission if left untreated?

- Yes, ignoring this code can lead to further damage to the transmission system, potentially resulting in costly repairs or even transmission failure.