P2E7E: A/C Compressor Control Module Internal Temperature Sensor B Circuit High

What it means

The ECM detects a circuit high fault on the a/c compressor control module internal temperature sensor b circuit. Reading cannot be used reliably for control.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Internal temperature sensor B monitors temperature inside the A/C compressor control module. The ECM monitors its circuit voltage; this code sets when the signal is higher than expected, often because the signal is shorted to B+ or the sensor circuit is open.

Common causes

Most likely first.

1. Signal wire shorted to B+
2. Open sensor
3. Connector pins corroded - high contact resistance

Symptoms

• Check-engine light may be on
• Air conditioning may be reduced or disabled

How to diagnose it

1. Use a scan tool to save freeze-frame data and check whether sensor B's reported temperature is implausibly high or fixed.
2. Inspect the compressor control module connector and sensor B wiring for an open, corrosion, damage, or a signal wire contacting B+.
3. Check whether the sensor B reading changes plausibly as the compressor operates, and compare it with available temperature data.
4. Using the manufacturer's wiring diagram, test the signal circuit for a short to B+ and check connector pin contact and continuity.
5. If the wiring passes, test sensor B for an internal open or other fault against the manufacturer's specification.

Common fixes

• Clean and secure corroded or loose sensor B connector contacts where serviceable.
• Repair an open circuit or a sensor B signal wire shorted to B+.
• Replace sensor B if it fails the manufacturer's electrical checks.

Can I keep driving?

The A/C may be limited or disabled because the compressor control module cannot rely on sensor B's temperature reading. Driving is generally possible if the vehicle behaves normally, but stop if an overheating warning appears.