Severity High
P284B

Shift Fork Stuck - Transmission Issue

📅 Last reviewed: July 2026
What does the P284B code mean?

The P284B code indicates that the transmission control module (TCM) has detected a stuck shift fork, which is a mechanical component responsible for engaging gears. This can prevent proper gear engagement, leading to shifting problems. The issue is often caused by mechanical binding, worn components, or low transmission fluid.

High
Severity
$50-$150
Typical Cost
High
Frequency

1. Most Common Causes

2. Symptoms You Will Notice

3. Step-by-Step Diagnosis

1

Step 1: Scan for codes and verify P284B is present.

2

Step 2: Check transmission fluid level and condition.

3

Step 3: Inspect shift fork actuator and wiring for damage.

4

Step 4: Perform a transmission adaptation reset or relearn.

4. Frequently Asked Questions

Is it safe to drive with this code?

No, driving with a stuck shift fork can cause further transmission damage or sudden loss of drive. It is recommended to have the vehicle towed to a repair shop.

How much does it cost to fix?

Diagnosis typically costs $50-$150. Repair costs vary widely; if the shift fork needs replacement, it can be $500-$1500 or more depending on labor and parts.

5. Commonly Affected Makes

This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.

6. Related Codes

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