DTC P00A200 — Charge Air Cooler Temperature Sensor Circuit Low (Bank 2).

✅ Meaning of P00A200

P00A2 sets when the ECM detects that the Charge Air Cooler Temperature (CACT) sensor signal on Bank 2 is lower than the expected range.

This usually means:

The sensor voltage is low
or

The sensor is reading too cold due to wiring/connector issues.

Bank 2 = the side without cylinder #1 (for V-engines).

🔧 Common Symptoms

Low engine power

Poor acceleration

Increased fuel consumption

Turbo underperformance

Black smoke (in some diesels)

MIL ON (Check Engine Light)

🔍 Possible Causes

Most common (80% of cases):

1. Faulty Charge Air Cooler Temp Sensor (Bank 2)

2. Damaged wiring harness (short to ground)

3. Corroded or loose connector at sensor

Less common:

4. Contaminated/intercooler full of moisture or oil

5. Sensor covered will carbon/soot

6. Faulty intercooler or airflow blockage

7. ECM internal fault (rare)

🧰 Tools Needed

OBD2 scanner with live data

Multimeter (voltage & resistance)

Wiring diagram (if available)

Basic hand tools

🛠️ Step-By-Step Diagnosis

1. Visual Inspection

Locate Bank 2 Charge Air Cooler Temp Sensor
(Usually on the intercooler outlet pipe or charge pipe).

Check:

Broken wires

Rodents damage

Oil-soaked connectors

Loose pins

Corrosion at connector

If damaged → repair → clear code → retest.

2. Check Live Data

Look at CACT Sensor (Bank 2) temperature:

Normal at ambient (engine cold):
Around 20–40°C depending on weather

If the reading shows very low or negative (-30°C etc.) → circuit low → wiring/sensor issue.

Compare Bank 1 vs Bank 2:
If Bank 2 is much lower → problem confirmed.

3. Test Sensor Wiring

Unplug the sensor.

Check 5V Reference

One pin should have 5V.

If 0V → short to ground / open circuit.

Check Ground

Should have good continuity to chassis.

Check Signal Wire

Should have ~5V with sensor unplugged.
Low = short to ground.

4. Check Sensor Resistance

With sensor removed and cold engine:

Typical NTC values:

At 20°C → 2–3 kΩ
At 80°C → 250–350 Ω

If reading is open (∞) or 0 Ω → replace sensor.

5. Intercooler Inspection (if needed)

Excessive oil

Moisture

Blocked airflow

Cracked charge pipe
These can cool air too much, causing abnormal readings.

🔧 Repairs That Solve P00A2

🎀 Replace Charge Air Cooler Temperature Sensor (Bank 2)
🎀 Repair/replace wiring harness
🎀 Clean connector pins
🎀 Clean intercooler / remove oil
🎀 Repair cracked intercooler hoses
🎀 Update ECM software (manufacturer specific)
🎀 Replace ECM (very rare)

🔄 After Repair

Clear code

Perform road test

Monitor CACT temperature values

Make sure Bank 1 and Bank 2 readings are close

Welcome To Madurai Car Service 💐🙏🏻.