How to diagnose a p0455 engine code?

How to diagnose a p0455 engine code?

Replace FTP sensor as per TSB 04-06-04-025A. A customer rolls in with a check engine light. You scan a P0455, an engine code that indicates a large evaporative emissions (EVAP) leak. Your first move: check the gas gap. So you tighten the cap, delete the code and send the customer on his way. A few days later, the light is back on.

How to diagnose an EVAP code in a vehicle?

VEHICLE APPLICATION: 2004 Grand Prix 3.8 AVG. REPORTED MILEAGE: 90,000 miles Apply vacuum to the disconnected tank hose at the evaporative canister. Test for fuel cap seal to tank filler neck. Test for leak at Fuel Tank Pressure (FTP) sensor. Replace FTP sensor as per TSB 04-06-04-025A. A customer rolls in with a check engine light.

What to do if your check engine light goes bad?

The first thing to check with this code is the gas cap. If it was left open or loose, close it tight and the “Check Engine” light should reset itself after a few drive cycles. Sometimes a gas cap itself can go bad. Have a closer look at it, if there is visible damage to the cap or its rubber gasket, it must be replaced.

Can a fuel pump leak cause an EVAP code?

If the tank hose leaks, the leak will usually be at the fuel pump gasket. The leak can be very small, with no liquid escaping, but big enough for vapor to escape, setting off the EVAP code. Moisture above the tank can also cause rust at the top, which can be a leak point as well.

How to ckeck engine light codes?

Chevy Check Engine Light Codes Connect scan tool to the 16-pin data link connector (DLC) located underneath the steering column. The connector may have a removable cover. Turn the ignition on. Follow scan tool manufacturer’s operating instructions to access the Diagnostic Trouble Codes (DTC’s).

What do the codes p0442 and p0456 mean?

The EVAP is designed to prevent your gasoline vapor from leaking into the atmosphere. It is monitored by the Powertrain Control Module (PCM), and the computer will notify a DTC P0442 when a small leak is detected. Similar codes are P0455 (EVAP control system leak detected large leak) and P0456 (EVAP control system leak detected very small leak).

What does p1456 check engine light code mean?

The P1456 code is detected when the EVAP system has a very small leak. This diagnosis detects leaks in the Evaporative Emission (EVAP) purge line using engine intake manifold vacuum.

What does this code mean p0455?

P0440 is the general code for a problem with the Fuel Evaporative Emission System. The P0455 code specifically indicates a large leak in the system, not a fuel leak, but one in the vapor recovery system.