P1191 — O2 Sensor Heater Circuit Open, HArdware Fault

What Does P1191 Mean?

P1191 is a manufacturer-specific diagnostic trouble code: O2 Sensor Heater Circuit Open, HArdware Fault. This code applies to JAGUAR, BMW, BUICK, CADILLAC, CHEVY vehicles. Unlike generic OBD-II codes, manufacturer-specific codes are defined by the vehicle maker and may only apply to certain makes and models.

Symptoms of P1191

⚠️ Check Engine Light (MIL) illuminated
⚠️ No signal from O2 Sensor Heater
⚠️ Related system defaulting to backup values
⚠️ Reduced engine performance

Common Causes

🔍 Broken wire in O2 Sensor Heater circuit
🔍 Disconnected O2 Sensor Heater electrical connector
🔍 O2 Sensor Heater internal open circuit failure
🔍 Corroded terminal pins preventing electrical contact

Frequently Asked Questions

What does P1191 mean?

P1191 indicates: O2 Sensor Heater Circuit Open, HArdware Fault. The vehicle's computer has detected that the O2 Sensor Heater is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1191?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1191 for extended periods may cause additional problems.

How much does it cost to fix P1191?

Repair costs for P1191 typically range from $30 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

🔧 Locate and repair broken wire in O2 Sensor Heater circuit
🔧 Replace damaged O2 Sensor Heater connector
🔧 Replace O2 Sensor Heater if internally open

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.

P1191: O2 Sensor Heater Circuit Open, HArdware Fault