Ford Power Stroke · Intake Air Temperature SensorMedium

Ford 6.7 Power Stroke P0113: Intake Air Temperature Circuit High Input

P-Code 0113 (FMI N/A) — Intake Air Temperature Circuit High Input

4.8/5· 128 reviews

Quick Answer

P0113 on the 6.7 Power Stroke means IAT voltage is above maximum — usually an open sensor, broken signal wire, or corroded connector making the PCM think intake air is extremely cold.

Overview: Ford Power Stroke P-Code 0113

P0113 is a common intake sensor code on the 6.7L Power Stroke that causes the PCM to over-fuel because it believes intake air is far colder than reality. At ProfessionalDieselRepair.com, we see this after pressure-washing engine bays (connector moisture), rodent-damaged wiring, and failed IAT elements in integrated MAF/IAT assemblies. A quick resistance test at the connector usually separates wiring faults from sensor failures.

Repair Snapshot

Time

30 Minutes - 1.5 Hours

Difficulty

Beginner

Parts Cost

$25 - $250

Dealer Labor

$300+

Tools Required

  • Jaltest Diagnostic System
  • Diesel Laptops Scan Tool
  • Multimeter
  • Scan Tool

What P-Code 0113 Means

P0113 on the 6.7L Power Stroke means the PCM detected intake air temperature (IAT) sensor voltage above the calibrated maximum — typically 4.5V or higher on a 5V reference circuit. An open signal wire, failed IAT sensor, or corroded connector causes the PCM to read near-full-scale voltage, which it interprets as extremely cold intake air. The engine may run rich, produce black smoke, and set fuel trim codes as a result.

Symptoms Drivers Notice

  • Check engine light, sometimes with P0113 as the only stored code
  • Black smoke at idle or light throttle from over-fueling based on false cold-air reading
  • Hard start or extended crank in warm weather when the PCM thinks intake air is frigid
  • Live data shows IAT reading -40°F or similar impossibly low temperature
  • Possible rough idle until the engine warms and fuel trims compensate

Most Likely Root Causes

Open-circuit IAT sensor or signal wire

Most Common

NTC thermistor failure or a broken signal wire pulls voltage to the 5V reference, producing a -40°F reading.

Corroded or moisture-filled connector

Common

Water intrusion at the intake sensor connector creates intermittent opens that set P0113, especially after engine bay washing.

Failed IAT element in integrated MAF/IAT assembly

Occasional

On later 6.7L models, the IAT is built into the MAF. IAT failure may require full MAF replacement even if airflow readings appear normal.

Common Misdiagnoses (Don't Waste Parts)

Parts-cannon MAF replacement for an IAT-only fault

Why it happens: Integrated MAF/IAT assemblies make techs replace the whole unit.

Do this instead: Test IAT resistance independently. If MAF airflow data is normal, look for a standalone IAT or wiring repair first.

Ignoring P0113 because the truck still runs

Why it happens: Fuel trim compensation masks the symptom temporarily.

Do this instead: Fix P0113 promptly — prolonged rich running wastes fuel and can foul the DPF with excess soot.

Master Tech Commentary

Mechanic's Notes

Shop tip: on 6.7L trucks where IAT is part of the MAF assembly, P0113 may require MAF replacement even if airflow readings look fine. ProfessionalDieselRepair.com advises resistance-testing the IAT circuit separately before a parts-cannon MAF swap.

Step-by-Step Diagnostic Procedure

  1. Step 1: Connect Jaltest or Diesel Laptops and read IAT live data at a known warm engine temperature. If the engine bay is 150°F+ but IAT reads below 0°F, the circuit is faulted.
  2. Step 2: Measure IAT sensor resistance with the engine off and sensor disconnected. At 77°F (25°C), typical NTC resistance is 2,000–3,000 ohms. Open circuit (infinite resistance) confirms a failed sensor or broken wire.
  3. Step 3: Back-probe the IAT signal wire at the connector with the sensor plugged in. Voltage above 4.5V at warm ambient temperature indicates an open signal circuit.
  4. Step 4: Inspect the IAT connector on the intake manifold or MAF housing for corrosion, bent pins, or moisture. The 6.7L IAT is often integrated into the MAF assembly on later models.
  5. Step 5: If the sensor and wiring test good, check PCM reference voltage and ground at the connector. A missing ground can also drive voltage high.

Live Data & Freeze-Frame Tips

Compare IAT to ambient air temperature (AAT) sensor readings on Jaltest. At a cold soak, both should be within 5°F. A large gap with IAT reading -40°F confirms the circuit fault.

Safety Warnings

  • Allow the engine to cool before reaching into the intake area near the turbo.
  • Use dielectric grease on connectors after cleaning — not petroleum-based products.
  • Disconnect the battery before unplugging sensors if the PCM is sensitive to voltage spikes.

When to Limp In vs Tow

Towing is not necessary. The truck runs rich but remains driveable, though fuel economy suffers and DPF soot loading may increase.

Prevention Tips for Fleets & Owner-Operators

  • Avoid direct pressure-washing of intake sensor connectors.
  • Inspect IAT wiring during routine under-hood checks for chafing or rodent damage.
  • Apply dielectric grease to connectors after any intake service.
  • Replace integrated MAF/IAT assemblies with OEM parts to maintain calibration.

Related Fault Codes

P0112

IAT circuit low input — opposite failure mode from a shorted sensor or signal wire.

P0102

MAF circuit low — may set together if the integrated MAF/IAT assembly fails.

P0117

ECT circuit low — coolant temp sensor faults can accompany intake wiring harness damage.

Frequently Asked Questions

What does P0113 mean on a 6.7 Power Stroke?

P0113 means the IAT sensor voltage exceeded the PCM maximum, typically reading as -40°F. The PCM over-fuels based on this false cold-air signal.

Can P0113 cause black smoke?

Yes. The PCM enriches the fuel mixture when it thinks intake air is very cold, producing black smoke especially at idle and light throttle.

How do I test the IAT sensor?

Measure resistance across the sensor terminals at known temperature. Compare to the service manual chart. Open circuit means replace the sensor or repair the wire.

Is IAT part of the MAF on 6.7L Power Stroke?

On many 6.7L models, yes — the IAT is integrated into the MAF housing. IAT failure may require MAF assembly replacement.

Will P0113 affect fuel economy?

Absolutely. Over-fueling from a false cold-air reading reduces MPG and can accelerate DPF soot accumulation.

Can a bad ground cause P0113?

Yes. A poor sensor ground can drive signal voltage high. Test ground resistance at the connector — it should be under 0.5 ohms to chassis.

More Ford Power Stroke codes on this system

All Ford Power Stroke fault codes

Guides that go deeper