AutoCodes – Generic – C0550

C0550 Code - Electronic Control Unit

Quick Answer

This is an internal fault detection of the Transfer Case Shift Control Module (TCCM). Common causes include Faulty Transfer Case Shift Control Module (TCCM), Transfer Case Shift Control Module (TCCM) harness is open or shorted, Transfer Case Shift Control Module (TCCM) 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: C0550 indicates Electronic Control Unit.
Common causes: Common causes include Faulty Transfer Case Shift Control Module (TCCM), Transfer Case Shift Control Module (TCCM) harness is open or shorted, Transfer Case Shift Control Module (TCCM) 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 30,771

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 Jun 27, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C0550 Description

This is an internal fault detection of the Transfer Case Shift Control Module (TCCM). This fault is handled inside the TCCM. No external circuits are involved.
At each power-up, the TCCM runs a self-test on the following:
- EEPROM Checksum
- ROM Checksum
- RAM Checksum
- RAM Malfunction

OBDII Code C0550 - Electronic Control Unit - AutoCodes.com — C0550 Code - Electronic Control Unit

What does this mean?

What are the Possible Causes of the DTC C0550?

Faulty Transfer Case Shift Control Module (TCCM)
Transfer Case Shift Control Module (TCCM) harness is open or shorted
Transfer Case Shift Control Module (TCCM) circuit poor electrical connection

How to Fix the DTC C0550?

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 C0550 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 C0550 code?

Need more information on how to fix the C0550 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C0550 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C0550 Buick — Electronic Control Unit
C0550 Cadillac — Electronic Control Unit
C0550 Chevrolet — Electronic Control Unit
C0550 GMC — Electronic Control Unit

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 C0550 Code

1. What is OBDII code C0550 related to the Electronic Control Unit (ECU)?

Code C0550 generally indicates a malfunction in the ECU, specifically a calibration error.

2. What are some common symptoms of OBDII code C0550?

Common symptoms include issues with engine performance, stalling, rough idling, or problems with the vehicle's transmission.

3. What are the potential causes of OBDII code C0550?

Possible causes of this code include faulty ECU programming, damaged wiring or connectors, or a problem with the ECU itself.

4. How do I diagnose OBDII code C0550?

Diagnosing this code typically involves using a diagnostic scanner to retrieve the code, followed by testing the ECU, wiring, and connectors for any issues.

5. Can OBDII code C0550 be repaired at home?

Repairing this code may require specialized tools and expertise. It is recommended to consult a professional mechanic for proper diagnosis and repair.

6. Is it safe to continue driving with OBDII code C0550 present?

Continuing to drive with this code may lead to further damage to the vehicle. It is advisable to address the issue promptly to prevent any potential safety hazards.

7. Can resetting the ECU fix OBDII code C0550?

Simply resetting the ECU may not resolve the underlying issue causing code C0550. Proper diagnosis and repair are necessary to address the root cause.

8. How much does it typically cost to repair OBDII code C0550?

The cost of repairing this code can vary depending on the cause of the issue and the labor rates of the repair shop. It is advisable to obtain estimates from multiple sources.

9. Are there any preventive measures to avoid OBDII code C0550?

Regular maintenance of the vehicle, including checking the wiring and connectors related to the ECU, can help prevent issues that may trigger code C0550.

10. Can a software update fix OBDII code C0550?

In some cases, a software update provided by the manufacturer may resolve code C0550 if it was caused by faulty ECU programming. It is recommended to consult the manufacturer or a professional mechanic for guidance.