P28AC — Cylinder 8 Ion Current Sense Circuit

What Does P28AC Mean?

P28AC is a diagnostic trouble code indicating: Cylinder 8 Ion Current Sense Circuit. This code relates to the powertrain system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.

Symptoms of P28AC

⚠️ Check Engine Light (MIL) illuminated
⚠️ Erratic Cylinder 8 Ion Current Sense readings
⚠️ Related system operating intermittently
⚠️ Reduced engine performance

Common Causes

🔍 Wiring issue in Cylinder 8 Ion Current Sense circuit (damaged, chafed, or corroded)
🔍 Faulty Cylinder 8 Ion Current Sense connector or terminal
🔍 Failed Cylinder 8 Ion Current Sense
🔍 ECM/PCM connection issue

Frequently Asked Questions

What does P28AC mean?

P28AC indicates: Cylinder 8 Ion Current Sense Circuit. The vehicle's computer has detected that the Cylinder 8 Ion Current Sense is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P28AC?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P28AC for extended periods may cause additional problems.

How much does it cost to fix P28AC?

Repair costs for P28AC 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 and repair Cylinder 8 Ion Current Sense wiring and connectors
🔧 Replace faulty Cylinder 8 Ion Current Sense

1
Find your vehicle above
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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.

P28AC: Cylinder 8 Ion Current Sense Circuit