AutoCodes – Generic – P1291

P1291 Code - No Temperature Rise Seen From Intake Air Heater

Quick Answer

Temperature rise from intake air heaters is monitored for first 15 seconds of engine operation. Common causes include Air heater relay fault, Battery cable condition, Electrical circuit fault. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1291 indicates No Temperature Rise Seen From Intake Air Heater.
Common causes: Common causes include Air heater relay fault, Battery cable condition, Electrical circuit fault.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 29,280

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 07, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1291 Description

Temperature rise from intake air heaters is monitored for first 15 seconds of engine operation. The P1291 code may be stored if initial Intake Air Temperature (IAT) sensor reading is 0-66°F (-17.8 to 18.8°C), Battery Temperature Sensor (BTS) and Intake Air Temperature (IAT) sensor are within 10°F of each other, time between end of preheat and engine run state is less than 30 seconds, engine is cranked for less than 5 seconds before engine starts, preheat is completed before engine starts, post-heat is active and no IAT sensor or intake air heater relay DTCs exist.

OBDII Code P1291 - No Temperature Rise Seen From Intake Air Heater - AutoCodes.com — P1291 Code - No Temperature Rise Seen From Intake Air Heater

What does this mean?

What are the Possible Causes of the DTC P1291?

Air heater relay fault
Battery cable condition
Electrical circuit fault

How to Fix the DTC P1291?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P1291 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P1291 code?

Need more information on how to fix the P1291 code? Get Access to Factory Service Manuals

Need Help with the Code?

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Information for Specific Makes

P1291 Audi — Engine Coolant Temperature Sensor High Input
P1291 Chrysler — No Temperature Rise Seen From Intake Air Heater
P1291 Dodge — No Temperature Rise Seen From Intake Air Heater
P1291 Ford — Injector High Side Short To Ground Or Battery Voltage Bank 1
P1291 Volkswagen — Engine Coolant Temperature Sensor High Input

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.