🚗 DTC P0095 — Intake Air Temperature Sensor 2 (IAT2) Circuit

Meaning:

The ECM detects an electrical fault (high/low/out of range) in the Intake Air Temperature Sensor 2 circuit.
IAT2 is usually located after the intercooler on turbo engines.

✅ Common Symptoms

Hard starting

Poor acceleration / low power

Black smoke (diesel)

High fuel consumption

Turbo boost drop (some models)

MIL/Check Engine light ON

🔧 Possible Causes

Electrical

IAT2 connector loose or corroded

Damaged wiring (rubbed, oil soaked, broken)

Short to ground or short to power

High resistance in wiring

Sensor Related

Faulty IAT2 sensor

Contaminated sensor (oil mist from turbo)

Water inside connector

ECM Related

Rare: ECM internal fault

Incorrect reference voltage

🧰 Step-By-Step Diagnostic Procedure

1. Visual Inspection

Locate IAT2 sensor (usually in charge pipe/intercooler outlet).

Check for:

Loose connector

Broken wires

Oil contamination

Pipe leak near the sensor (can affect readings)

Fix any physical issue first.

2. Check Wiring Voltage (Key ON)

Use a multimeter at the IAT2 connector:

Pin Expected Value

5V reference 4.8–5.1V
Ground Good continuity
Signal wire ~1–4V depending on temperature

If 5V is missing → trace open/short to ECM.

If ground missing → repair ground circuit.

3. Test IAT2 Sensor

Unplug the sensor → resistance test:

Typical IAT2 thermistor resistance:

20°C: 2,000–3,000 ohms

40°C: 1,000–1,500 ohms

60°C: 500–900 ohms

If resistance does not change smoothly with heat → sensor is faulty.

4. Live Data Check (Scan Tool)

Look at IAT2 temperature reading:

If it shows –40°C or -40°F → open circuit

If it shows +140°C or unrealistic high temp → short to ground

If fluctuating → poor wiring contact

5. Check Intake System Leaks

Air leaks near IAT2 sensor affect readings:

Intercooler hose cracks

Loose clamps

Turbo outlet leaks

Repair leak + clear codes.

6. ECM Check (Last Option)

If wiring and sensor are good → ECM may have internal signal circuit fault.
Check continuity from connector to ECM before replacing ECM.

🛠️ Most Common Fixes

🌟 Replace faulty IAT2 sensor
🌟 Repair damaged wiring
🌟 Clean sensor connector & remove corrosion
🌟 Fix intercooler pipe leaks
🌟 Replace connector pigtail (if loose or broken)
🌟 Rare: Replace/update ECM

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