P2A33 concerns the control line that grounds the coil of the relay supplying the gas control module. Low means this line already sits near zero volts while the driver is switched off. A chafed wire touching the body is the classic finding; a coil with shorted windings can give the same picture. Since the coil is then permanently grounded, the relay may stay energised after the key is off, keeping the gas module awake and draining the battery overnight. Nobody publishes this code for a production gas system. Saab's GM Europe V6 manual, written for the engine relay twin P0686, lets the test run only between 10 and 18 V supply with the engine turning above 80 rpm and classes it as a Type C code, meaning no warning lamp there. CARB expects actuator outputs to be checked for such shorts.
Medium severity. Can I keep driving?If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
Symptoms
- Check engine light, depending on calibration
- Battery flat after the vehicle has been parked
- Gas module stays active after ignition off
Most likely causes
- Control wire chafed through and touching ground
- Shorted turns in the relay coil
- Moisture in the relay socket bridging to ground
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P2A33 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- A: Hybrid or air and fuel
- 33: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2A33?
If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
What causes code P2A33?
The most common causes are: control wire chafed through and touching ground; shorted turns in the relay coil; moisture in the relay socket bridging to ground.
Related codes
- P2A32AFCM Power Relay Control Circuit/Open
- P2A34AFCM Power Relay Control Circuit High
- P2A36AFCM Power Relay Sense Circuit Low
- P0686ECM/PCM Power Relay Control Circuit Low
- U0108Lost Communication With Alternative Fuel Control Module
Sources
- law.cornell.edu: 13 CCR 1968.2
- saabwisonline.com: dtc p0685 p0686 p0687 p0689 or p0690
- static.nhtsa.gov: INRD PE08063 33504P
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.