Damaged, chafed or corroded wiring to the tank pressure sensor (open circuit, short to earth or short to supply); Loose, corroded or water-affected connector at the sensor or control unit; Faulty alternative fuel tank pressure sensor; Poor earth or a missing sensor reference supply voltage; Fault in the gas system control unit or engine control unit; Poor aftermarket conversion wiring or a bad splice (on converted vehicles).

P019E

Alternative Fuel Tank A Pressure Sensor Circuit.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
1: AreaFuel and air metering
9E: FaultThe specific fault in that area

What it means

P019E is the generic code for a fault in the circuit of the pressure sensor on alternative fuel tank A, such as the CNG or LPG tank on a bi-fuel or dedicated gas vehicle. The control unit has seen a sensor signal or reference voltage outside the expected electrical range, or a signal that does not make sense. How the fault is set (low, high, erratic or no signal) depends on the vehicle and the gas system fitted.

Symptoms

Engine warning light on
Gas (CNG or LPG) mode unavailable, or the car stays on petrol
Fuel level or tank pressure reading on the gauge or display missing or wrong
Reduced range on alternative fuel
Poor starting or hesitation when switching fuels
Possible extra fault codes from the gas system control unit

Possible causes

Damaged, chafed or corroded wiring to the tank pressure sensor (open circuit, short to earth or short to supply)likely
Loose, corroded or water-affected connector at the sensor or control unitlikely
Faulty alternative fuel tank pressure sensorlikely
Poor earth or a missing sensor reference supply voltagepossible
Fault in the gas system control unit or engine control unitrare
Poor aftermarket conversion wiring or a bad splice (on converted vehicles)possible

How to diagnose

Read all stored and pending codes and the freeze frame data, and note whether other gas system or fuel codes are present
Check the live tank pressure reading against the gauge or known tank state, and see whether it is stuck, implausible or jumping
Inspect the sensor, its wiring and the connectors for damage, chafing, corrosion, water or heat damage, and check the harness routing near the tank
Wiggle-test the harness and connectors with live data showing, to look for intermittent faults
Check the sensor reference supply, signal and earth at the connector against the manufacturer's wiring diagram and specification
Test the wiring for continuity and for shorts to earth or supply, with the connectors disconnected
Check the sensor against the manufacturer's test procedure, as sensor type and values vary by model and gas system
Check for relevant software updates or technical bulletins for your vehicle once the wiring and sensor are ruled out

How to fix

Repair or replace damaged wiring, and secure and protect the harness
Clean, repair or replace faulty connectors and terminals
Replace the tank pressure sensor if it fails testing, following the gas system's safe depressurising and sealing procedure
Restore the correct earth or supply to the sensor circuit
Repair or replace the control unit only after the wiring and sensor are proven good and the manufacturer's procedure calls for it
Clear the code after repair and road test to confirm it does not return

Can I keep driving?

Medium severity

The car can usually be driven on petrol, but the gas system may be unavailable and the tank pressure reading cannot be trusted. Book it in soon, and have it checked at once if you smell gas or see leaks, as a gas system fault is a safety matter.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.