P0D70: A/C Compressor Control Module Internal Temperature Sensor A Circuit

What it means

The ECM detects a circuit 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

Temperature sensor A inside the A/C compressor control module reports the module’s internal temperature so the system can protect itself from heat. This code sets when the sensor circuit has a general electrical fault and the module cannot rely on that temperature reading.

Common causes

Most likely first.

1. Sensor failed
2. Wiring or connector fault

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. Save freeze-frame data and read internal temperature sensor A live data to see whether the reading is missing, implausible, or fixed.
2. Inspect the compressor control module connector and nearby harness for loose pins, corrosion, heat damage, or chafing.
3. Check the sensor circuit’s power, ground, and signal wiring for opens and shorts using the vehicle wiring diagram.
4. Compare the sensor reading and circuit measurements with the manufacturer’s specification, accounting for actual module temperature.
5. If wiring and connector tests pass, test the internal temperature sensor and compressor control module as directed by the manufacturer.

Common fixes

• Reseat and secure the compressor control module connector.
• Repair damaged or corroded sensor wiring and terminals.
• Restore a faulty sensor circuit power or ground connection.
• Replace the internal temperature sensor or control module only if the specified tests identify it as faulty.

Can I keep driving?

The module may limit or disable A/C operation because it cannot reliably monitor its internal temperature. Driving is generally possible if no other warnings are present, but have the fault diagnosed promptly and avoid relying on A/C for defogging.