P0D74: A/C Compressor Control Module Internal Temperature Sensor A Circuit Intermittent/Erratic

P0D74 reports an unsteady signal from the internal temperature sensor of the A/C compressor control module: the reading jumps or drops out in short bursts rather than sitting at one wrong value. No manufacturer publishes a threshold for P0D74. GM's 2019 Volt table names it, together with P0D71 to P0D73, as a fault that blocks other compressor diagnostics, which ties it to the same sensor, but it gives no set criteria. A Hyundai patent on temperature sensors of power switches describes how loose connectors, noise, board defects or cold solder joints produce exactly such erratic values. Because the sensor is part of the compressor electronics, a confirmed fault usually ends with a new assembly; check the 12 V supply, ground and data connections first.

Symptoms

• Air conditioning cuts out now and then
• Code appears sporadically

Most likely causes

• Cold or cracked solder joint on the compressor board
• Loose low-voltage connector or ground at the compressor
• Electrical interference on the sensor signal

What to check, in order

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

1. Check the battery and grounds
2. Gently move the wiring with the engine running and watch whether the reading changes.
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 P0D74 means

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

Frequently asked questions

Can I keep driving with code P0D74?

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 P0D74?

The most common causes are: cold or cracked solder joint on the compressor board; loose low-voltage connector or ground at the compressor; electrical interference on the sensor signal.

Related codes

• P0D70A/C Compressor Control Module Internal Temperature Sensor A Circuit
• P0D71A/C Compressor Control Module Internal Temperature Sensor A Performance
• P0D72A/C Compressor Control Module Internal Temperature Sensor A Circuit High
• P0D73A/C Compressor Control Module Internal Temperature Sensor A Circuit Low
• P0D79A/C Compressor Control Module Output Driver Temperature Sensor Circuit Intermittent/Erratic

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 19OBDG01 Hybrid Diagnostics
• patents.google.com: en

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.