SES Light Due to P0300 - Inspect Fuel System for Rust Contamination - keywords 2.2 CEL DTC engine filter idle injector L61 line load metal MIL miss rail repeat replacement restricted SES water

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

On rare occasions, an engine misfire and SES light may be experienced with DTC P0300, P0301, P0302, P0303, and/or P0304. This may be a result of rust contamination in fuel system, obstructing fuel delivery. Rust may form due to water in the fuel, causing the chassis fuel pipe (steel line from the fuel filter to engine compartment) to rust.

If this concern is encountered and the SI diagnostics lead to restricted fuel injectors, inspect the fuel rail and fuel injectors for rust contamination. If it is necessary to replace the fuel injectors due to rust contamination on the inlet of the fuel injector, the following steps should also be performed to prevent a reoccurrence:

1. Inspect the fuel feed tube inside of fuel rail for surface rust and replace rail as necessary.
2. Inspect the inside of the steel chassis fuel pipe for signs of rust at fuel filter connection and replace as necessary.
3. Flush the fuel rail and the fuel feed jumper pipe that attaches between the fuel rail and chassis fuel pipe. It is not necessary to replace either of these components since they are stainless steel; it is only necessary to flush/clean them out.
4. Inspect the charcoal canister for signs of water intrusion and replace as necessary.
5. If the last 8 digits of the VIN is 3Z169460 or lower, replace the fuel tank filler neck using the one listed in the parts catalog. The replacement filler neck has an updated design. Vehicles after this breakpoint were manufactured with this updated filler neck.
6. Inspect the fuel pump module for signs of rust and replace as necessary.
7. Properly dispose of the existing fuel and clean the inside of the fuel tank by following the "Fuel System Cleaning" procedure in SI.
8. Replace fuel filter to complete the repairs.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.