P2E7D: A/C Compressor Control Module Internal Temperature Sensor B Range/Performance

What it means

The ECM detects a range/performance fault on the a/c compressor control module internal temperature sensor b. 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 checks whether the reading behaves within the expected range; this code sets when sensor B's value is implausible for operating conditions, even if the circuit is not simply open or shorted.

Common causes

Most likely first.

1. Sensor characteristic drifted
2. Sensor mounting displaced
3. Sensor element aged beyond calibration window

Symptoms

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

How to diagnose it

1. Use a scan tool to capture freeze-frame data and compare sensor B's reported temperature with compressor operation and other available temperature readings.
2. Check live data from a cold start and during A/C operation for a sensor B value that responds too slowly, drifts, or disagrees implausibly with conditions.
3. Inspect the compressor control module and sensor B mounting area for displacement, poor contact, or signs the sensor is not positioned as designed.
4. Inspect the sensor B connector and wiring for damage or corrosion that could alter the reading without creating a clear open or short.
5. If mounting and wiring are sound, test sensor B's temperature response against the manufacturer's specification.

Common fixes

• Reposition or secure sensor B if it has shifted from its intended mounting position.
• Clean or repair a poor sensor B connector contact.
• Repair damaged wiring affecting sensor B's reading.
• Replace sensor B if its response has drifted outside the manufacturer's specification.

Can I keep driving?

The A/C may be reduced or disabled to protect the compressor control module. Driving is generally possible if the vehicle otherwise operates normally, but stop if an overheating warning or other hybrid-system fault appears.