What is P0400 code malfunction?

Question

1 Answer

Need A Repair Shop?

Find local automotive repair shops in your area.

Carguy1 · Answer 1 · 2018-05-13T14:59:49+0000

Hi there,

This code is a result of the EGR system not working properly. Here is a list of possible causes.

Check The Following Conditions:

Vacuum hoses for poor connections, leakage, deterioration, clogged or incorrect routing.
EGR valve malfunction, stuck closed, stuck open, clogged.
EGR pressure transducer malfunction.
EGR solenoid vacuum valve and the EGR bypass valve and their circuitry for malfunctions.
Poor connection at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
Damaged harness. Inspect the wiring harness for damage.