P0D73: A/C Compressor Control Module Internal Temperature Sensor A Circuit Low

P0D73 is the low-signal circuit code for the internal (CPU) temperature sensor of the compressor control module. For an NTC sensor a low signal corresponds to an implausibly hot reading. GM sets it above 274 °C in the 2011–2015 Volt and 2016 ELR, and above 150 °C in the 2016–2019 Volt, where the compressor itself detects the condition and reports it over GMLAN; counting is 30 of 60 samples at 50 ms, 40 of 50 at 100 ms or 4 of 5 s depending on the year, Type B. Values like these suggest a shorted sensor rather than real heat, although genuine overheating of the electronics should be ruled out by checking. The compressor may limit or stop operation. The cold-side code is P0D72, plausibility P0D71.

Symptoms

• Check engine light after two trips
• Air conditioning reduced or switched off

Most likely causes

• Short circuit in the internal temperature sensor path
• Real overheating of the compressor electronics
• Faulty value transmission to the host controller

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the battery and grounds
2. With the connector unplugged, check whether the signal wire is making contact with ground.
3. Clear the code and see if it returns
4. If it is a reference voltage code, disconnect sensors one at a time and see if the voltage recovers
5. Check whether a software update is available
6. Do not replace the control module without a full diagnosis

What each character of P0D73 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• D: Subsystem depends on the code range
• 73: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0D73?

It depends on the symptoms. If the car is running normally you can go to a repair shop; if it goes into limp mode, drive as little as possible.

What causes code P0D73?

The most common causes are: short circuit in the internal temperature sensor path; real overheating of the compressor electronics; faulty value transmission to the host controller.

Related codes

• P0D72A/C Compressor Control Module Internal Temperature Sensor A Circuit High
• P0D71A/C Compressor Control Module Internal Temperature Sensor A Performance
• P0D70A/C Compressor Control Module Internal Temperature Sensor A Circuit
• P0D74A/C Compressor Control Module Internal Temperature Sensor A Circuit Intermittent/Erratic
• P0D78A/C Compressor Control Module Output Driver Temperature Sensor Circuit Low

Sources

• gsi.ext.gm.com: 11OBDG01 HYBRID Diagnostics
• gsi.ext.gm.com: 16OBDG01 Hybrid Diagnostics
• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.