Fuel and air

P019E — Alternative Fuel Tank A Pressure Sensor Circuit Fault

Severity: medium Drive with care, to a shop

What P019E means

The engine control unit monitors the pressure sensor on alternative fuel tank A, such as a CNG or LPG cylinder. P019E sets when the signal is out of range, missing or doesn't make sense, for example from an open or shorted circuit. Without reliable pressure data the ECU can't meter gas accurately and may disable alternative fuel operation.

Symptoms

  • Check Engine Light on
  • Rough idle or hesitation
  • Reduced power and performance
  • Higher fuel consumption
  • Vehicle won't switch to gas or runs only on gasoline
  • Possible gas smell if there is a leak

Possible causes

  1. Faulty alternative fuel tank pressure sensor
  2. Open, chafed or shorted wiring in the sensor circuit
  3. Corroded or loose connector terminals
  4. Leak or abnormal pressure in the tank or fuel line
  5. Faulty regulator, valve or fuel pump affecting pressure
  6. ECU or gas control module fault (rare)

How to diagnose

  1. Scan for all codes and review freeze frame data, noting other alternative fuel codes
  2. Inspect the system and check for gas odor; if there is a leak, ventilate and don't continue until it's addressed
  3. Visually inspect the sensor, connector and harness for rubbing, corrosion or moisture
  4. Check the 5 V reference and ground at the sensor connector with a multimeter
  5. Compare scan tool pressure reading with a mechanical gauge
  6. Test the wiring to the ECU for opens and shorts
  7. Check the valves, regulator and pump that affect pressure
  8. Clear the code and road test to confirm the repair

Common fixes

  • Replace the tank pressure sensor
  • Repair the wiring harness or replace the damaged connector
  • Clean the terminals and secure the connector
  • Fix the leak or replace the faulty tank, valve or regulator
  • Update software or replace the control module if confirmed faulty

Questions and answers

What does P019E mean?

It's a circuit fault in the Alternative Fuel Tank A pressure sensor. The ECU sees an incorrect or missing signal from the sensor.

Can I drive with P019E?

Usually yes, often on gasoline with reduced efficiency. If you smell gas, don't drive; have the system checked right away.

How do I clear P019E?

Fix the cause first: the sensor, wiring or a leak. Then clear the code with a scan tool; if the fault remains, it will return.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.