P2ACB: Charge Air Cooler Coolant Temperature Sensor B Circuit Intermittent/Erratic

What it means

The charge air cooler coolant temperature B sensor signal drops out or jumps intermittently. Loose connector or noisy ground.

At a glance

• Usually lights the check-engine light

How it works

Charge air cooler coolant temperature sensor B reports coolant temperature through an electrical signal. This code sets when the signal from sensor B changes erratically or briefly drops out, rather than remaining stable as operating conditions change.

Common causes

Most likely first.

1. Intermittent wiring or connector fault
2. Intermittent sensor fault
3. Poor ground connection

Symptoms

• Check-engine light may be on
• Intermittent loss of power
• Unusual changes in engine response

How to diagnose it

1. Check freeze-frame data and review sensor B's live reading for sudden jumps or dropouts, including while gently moving the harness.
2. Inspect sensor B's connector for looseness, corrosion, moisture, or terminals that do not grip securely.
3. Trace the sensor B wiring for chafing, stretched sections, or damage near hot or vibrating components.
4. Check the sensor B ground and signal connections for intermittent contact while monitoring the live reading.
5. If the wiring remains sound, test sensor B's output through its temperature range against the manufacturer's specification.

Common fixes

• Secure the sensor B connector and clean or repair intermittent terminal contact.
• Repair chafed or broken wiring in the sensor B circuit.
• Restore a poor sensor ground or connection.
• Replace sensor B if its output remains erratic with sound wiring.

Can I keep driving?

Because power loss can occur unpredictably, avoid high-speed traffic, towing, and situations where sudden loss of acceleration would be hazardous. If the engine response becomes unreliable, stop in a safe place.