DTC P007D00 – Charge Air Cooler Temperature Sensor Circuit High (Bank 1).

✅ What P007D00 Means

The ECM detects that the Charge Air Cooler Temperature Sensor (CACT / IAT2) is showing a high voltage signal, which means the sensor is reading an abnormally low temperature.
This sensor is usually located after the intercooler on turbocharged engines.

High circuit = high voltage = sensor reads very cold air.

✅ Common Causes

1. Open circuit in the sensor signal wire

Broken wire

Corrosion in connector

Loose pins

2. Sensor unplugged

If the sensor is disconnected, the ECU reads maximum voltage → triggers code.

3. Faulty CACT sensor (IAT2)

Internal open circuit

Sensor element damaged

4. High resistance in wiring

Corroded terminals

Partially cut harness

Moisture in connectors

5. Intercooler leak / severe cold airflow

Rare, but sometimes extreme airflow cooling can affect readings.

6. ECM issue (very rare)

✅ What Symptoms You May See

Low engine power

Turbo boost limitation (Limp mode)

High fuel consumption

Poor acceleration

Check Engine Light ON

🔧 Step-by-Step Diagnostic Procedure

1. Visual Inspection

🌟 Locate the Charge Air Cooler Temperature Sensor (Bank 1) – normally on charge pipe after intercooler.
Check for:

Damaged connectors

Broken wires

Oil contamination

Water inside plug

Connector not locked properly

🌟 Fix any visible damage and clear code.

2. Check Sensor Resistance (Key Off)

Remove connector and measure sensor resistance.

Typical thermistor sensor values:

20°C → 2K–3K ohms

40°C → 1K ohm

60°C → 500–700 ohms

If resistance = infinite / open circuit → sensor is faulty.

3. Check Reference Voltage

With ignition ON:

Pin 1: 5V reference

Pin 2: Ground

Pin 3: Signal wire

If 5V supply is missing → ECM issue or wiring open.

4. Check Signal Voltage

Back-probe signal wire:

Normal operating: 0.5V – 4.0V

If 5V constant → circuit open / sensor unplugged / bad sensor.

5. Wiggle Test

While engine idling:

Wiggle harness

Observe live data

If temperature suddenly drops → broken or loose wiring.

6. Scan Tool Live Data

Check:

IAT1 (before intercooler)

IAT2 / CACT (after intercooler)

Normally:

IAT2 slightly higher than IAT1 when boosting

IAT2 should not be very low (below ambient)

If IAT2 shows -30°C or unrealistic low, sensor circuit is open.

🛠 Most Common Fixes

🎀 Repair open/ broken signal wire
🎀 Replace corroded connectors
🎀 Replace Charge Air Cooler Temperature Sensor (IAT2)
🎀 Repair/replace CACT harness
🎀 Clear codes & perform test drive

Welcome To Madurai Car Service 💐🙏🏻.