P2A48: Alternative Fuel Tank C Pressure Sensor Circuit Low

With P2A48 the voltage from the tank C pressure sensor has fallen beneath the lowest value a working sensor ever outputs, even with the cylinder empty. In such three-wire circuits a low reading points to the signal line touching ground, a dead 5 V supply or a short inside the transducer. The gas conversion specialist TransEco attributes its tank A Low code to a sensor shorted to ground and lets the AFCM continue with a fixed 3600 psi substitute while the lamp is on. For the driver, tank C looks drained: the gauge may sink and the module may skip that cylinder although it is still full. No manufacturer documents P2A48 itself. If the reference wire also feeds other sensors, a short elsewhere on it can trigger this code.

High severity. Can I keep driving?If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.

Symptoms

Check engine light
Tank C reported empty despite being filled
Less gas range than expected

Most likely causes

Signal wire of the tank C sensor touching ground
5 V reference open or shorted by another sensor on the same line
Internal short in the tank C transducer

What to check, in order

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

If you smell gas, shut off the supply, ventilate and do not start the engine
With the connector unplugged, check whether the signal wire is making contact with ground.
Read the codes with a compatible scanner
Check the connectors and wiring of the component indicated
Leave any work on the gas circuit to an authorized shop

Good to know

Repair difficulty: hard
It affects emissions.

What each character of P2A48 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
A: Hybrid or air and fuel
48: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2A48?

If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.

What causes code P2A48?

The most common causes are: signal wire of the tank C sensor touching ground; 5 V reference open or shorted by another sensor on the same line; internal short in the tank C transducer.

Related codes

Sources

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.