P0D72: A/C Compressor Control Module Internal Temperature Sensor A Circuit High

What it means

The ECM detects a high fault on the a/c compressor control module internal temperature sensor a 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

The A/C compressor control module uses internal temperature sensor A to monitor its own temperature and protect compressor operation. This code sets when the sensor circuit reads higher than the module can reliably use, such as from a signal shorted to power, an open sensor, or poor connector contact.

Common causes

Most likely first.

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

Symptoms

• A/C warning light may come on
• Air conditioning may provide little or no cooling
• A/C operation may be limited or disabled

How to diagnose it

1. Use a scan tool to record freeze-frame data and check the reported temperature-sensor fault before clearing anything, so you can see when the high reading occurred.
2. Inspect sensor A's connector and accessible wiring for corrosion, loose pins, damage, or a signal wire contacting a power feed.
3. Check the sensor signal and reference circuits for an open or short to power using the vehicle wiring diagram and manufacturer's test procedure.
4. Measure sensor A and its circuit continuity with power isolated as specified by the manufacturer, then compare the results with its specification.
5. If the wiring and sensor test correctly, check the compressor control module connection and follow the manufacturer's procedure to assess the module.

Common fixes

• Clean and secure corroded or loose sensor A connector pins.
• Repair a signal wire shorted to power or an open in the sensor circuit.
• Replace internal temperature sensor A if it fails the manufacturer's test.
• Repair or replace the compressor control module if its input circuit is confirmed faulty.

Can I keep driving?

The vehicle can usually be driven without A/C, but cooling may be disabled to protect the compressor electronics. Avoid relying on the air conditioning, and stop using it if the vehicle displays a hybrid or EV system warning or other signs of overheating.