P1291 Possible Causes
- Air heater relay fault
- Battery cable condition
- Electrical circuit fault
How do I fix code P1291
Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
Cost of diagnosing the P1291 code
Labor: 1.0The cost of diagnosing the P1291 code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
P1291 Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1291 MeaningTemperature 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.
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