P21B6 — Cold Start Cylinder 1 Injection Timing

What Does P21B6 Mean?

P21B6 is a diagnostic trouble code indicating: Cold Start Cylinder 1 Injection Timing. This code relates to the powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P21B6

⚠️ Check Engine Light (MIL) illuminated
⚠️ Cold Start Cylinder 1 Injection Timing not functioning as expected
⚠️ Related system may be in fail-safe mode
⚠️ Reduced engine performance

Common Causes

🔍 Faulty Cold Start Cylinder 1 Injection Timing
🔍 Wiring or connector issue in Cold Start Cylinder 1 Injection Timing circuit
🔍 Related mechanical or electrical fault
🔍 ECM/PCM issue (rare)

Frequently Asked Questions

What does P21B6 mean?

P21B6 indicates: Cold Start Cylinder 1 Injection Timing. The vehicle's computer has detected that the Cold Start Cylinder 1 Injection Timing is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P21B6?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P21B6 for extended periods may cause additional problems.

How much does it cost to fix P21B6?

Repair costs for P21B6 typically range from $80 to $300, depending on the root cause. Simple wiring or connector repairs are on the lower end, while component replacement costs more. A proper diagnosis ($80–$150 at most shops) will identify the exact cause before committing to expensive parts.

What To Do Next

Possible Fixes

🔧 Inspect Cold Start Cylinder 1 Injection Timing and related wiring
🔧 Replace faulty Cold Start Cylinder 1 Injection Timing

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P21B6: Cold Start Cylinder 1 Injection Timing