What are the fault codes for the EGR valve?
EGR valve fault codes that light up the check engine light (CEL) on your instrument cluster. P0401 EGR System Flow Insufficient. P0403 EGR Solenoid Circuit. P0404 EGR System Performance. P0405 EGR Pintle Position Circuit Low Voltage. P1404 EGR Valve Stuck Open. P1406 EGR Valve Pintle Position. Rough idle.
What happens when the EGR valve gets stuck on a GM 4.3L?
This tutorial addresses a very common problem I’ve seen on the 1987-1995 GM 4.3L, 5.0L, and 5.7L engines with throttle body fuel injection system: a stuck open EGR valve. And when the EGR valve gets stuck open, it’ll cause a rough idle condition that may hard to diagnose.
Can a vacuum be used to open an EGR valve?
A vacuum-operated EGR valve is usually only found in older vehicles. It is a straightforward system which utilises a vacuum to switch the EGR valve from closed to open. The vacuum is often regulated by a computer-controlled solenoid.
What is the other side of the EGR vacuum solenoid?
The other side of the EGR vacuum solenoid has 2 ports. One is a vent port (that vents vacuum to the atmosphere) when the engine is idling. The other port connects to the EGR valve and should only have vacuum when the PCM commands the solenoid to activate.
What happens when the EGR valve gets stuck?
So, when the EGR valve gets stuck open, it isn’t able to stop the flow of exhaust gas from entering the intake manifold and thus the combustion chamber and your pickup or SUV will idle rough. Here’s a few more specific symptoms you’ll see: Rough idle. Code 32: EGR System Problem. Code 33: MAP Sensor Signal High.
The other side of the EGR vacuum solenoid has 2 ports. One is a vent port (that vents vacuum to the atmosphere) when the engine is idling. The other port connects to the EGR valve and should only have vacuum when the PCM commands the solenoid to activate.
What does the EGR valve do on a GM 4.3L?
More GM 4.3L, 5.0L, 5.7L Tutorials. As you’re probably already aware, the EGR valve’s job is to let a metered amount of exhaust gas (that is oxygen free) into the intake manifold to reduce the amount of oxygen entering the engine.
What can I use to clean an EGR valve?
This is a home experiment and an unbiased use of JLM Diesel Air Intake & EGR Cleaner. Similar products are available. This product is designed to dissolve carbon deposits, gum and varnish build up. It should restore air flow to the engine thus improving power and acceleration while reducing exhaust smoke.
When to open the EGR valve when idle?
A good rule of thumb: If the EGR ports are clean, then the engine should stall or run very rough when opening up the EGR valve when the engine is at idle.
What happens when something goes wrong with the EGR system?
When something goes wrong with the EGR system, you usually see one of the following: Chunks of carbon blocking the EGR valve’s pintle from fully seating in its seat. Now, as you may already know, exhaust gas cannot recirculate back into the engine at engine idle.
What does p0401 EGR system insufficient flow detected mean?
So you have changed the EGR valve and this p0401 code continues to pop up on the computer. You are frustrated and ready to drive your car off of a cliff. What does this P0401 diagnostic trouble code mean anyway? The correct definition for this diagnostic trouble code P0401 is “ Insufficient EGR Flow Detected “.
Is there a problem with the GM EGR valve?
This design (either by intent or incompetence on the part of GM -after all, Ford and other makes don’t have this problem) has made auto repair shops tons and tons of money (before someone sues me… let me tell you that this is just my opinion).
Where can I find the EGR valve test?
To make sure this tutorial applies to your specific vehicle, check this section out first: Identifying The EGR Valve. You can find this tutorial in Spanish here: Cómo Probar La Válvula EGR Electrónica (3.1L, 3.4L GM) (at: autotecnico-online.com ).
How many wires are in an EGR valve?
There are 5 wires sticking out of the EGR valve’s connector, in this section we’ll explore what each one does. Most of the EGR valves will have the letters A thru’ E molded onto the EGR valve’s connector. I’ll be using these same letters for the circuit descriptions below: Ground circuit for EGR valve solenoid. Gray with Black stripe wire.