P1115 — Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B Circuit High Input

What Does P1115 Mean?

P1115 is a manufacturer-specific diagnostic trouble code: Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B Circuit High Input. This code applies to FORD, OTHER, LINCOLN, MERCURY, OLDSMOBILE 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 P1115

⚠️ Check Engine Light (MIL) illuminated
⚠️ Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B reading stuck at maximum value
⚠️ Related system operating erratically or in default mode
⚠️ Reduced engine performance

Common Causes

🔍 Short to voltage in Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B wiring harness
🔍 Corroded or water-damaged Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B connector
🔍 Faulty Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B outputting maximum voltage
🔍 Damaged wiring rubbing against metal components
🔍 ECM/PCM internal fault (rare)

Frequently Asked Questions

What does P1115 mean?

P1115 indicates: Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B Circuit High Input. The vehicle's computer has detected that the Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B is not operating within its expected parameters and stored this diagnostic trouble code.

Can I drive with code P1115?

You can drive short distances for essential trips, but schedule a diagnosis soon. Driving with P1115 for extended periods may cause additional problems.

How much does it cost to fix P1115?

Repair costs for P1115 typically range from $20 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 Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B wiring for short to voltage
🔧 Clean or replace corroded Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B connector
🔧 Replace faulty Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B

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2
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3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

P1115: Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage IAT - B Circuit High Input