1996 Chevrolet Monte Carlo Logo

Related Topics:

isaac Posted on Jul 10, 2012

Fault code p0401 and car wont start

My car wont start, it has power, I jumped the starter it ran for a couple seconds and shut itself down. I also hooked it up to a computer and got the fault code p0401 egr flow insufficient

5 Related Answers

Anonymous

  • 15935 Answers
  • Posted on Mar 18, 2009

SOURCE: Insufficient EGR Flow problem

Specifically DTC P0401 is "Exhaust Gas Recirculation (EGR) Insufficient Flow". Now this is where we have to be careful when we read a code. In this case it is not saying the EGR valve is bad, it's saying the EGR flow is too low. Now it could be because the EGR valve is bad. Or it could be a clogged EGR tube or a broken vacuum line. This is why you have to be careful and check the whole system before you go changing parts. The PCM tests the EGR system during deceleration by momentarily commanding the EGR valve to open while monitoring the Manifold Absolute Pressure (MAP) sensor signal. When the EGR valve is opened, the PCM should see a proportional increase in MAP. If the expected increase in MAP is not seen, the PCM notes the amount of error that was detected and adjusts an internal fail counter towards a fail threshold level. When the fail counter exceeds the fail threshold level, the PCM will set DTC P0401. The number of test samples required to accomplish this may vary according to the amount of detected flow error. Normally, the PCM will only allow one EGR flow test sample to be taken during an ignition cycle. To aid in verifying a repair, the PCM allows twelve test samples during the first ignition cycle following a scan tool Clear Info or a battery disconnect. Between nine and twelve samples should be sufficient for the PCM to determine adequate EGR flow and pass the EGR test. To check the system first you need to remove the EGR valve and if it is clogged or broken. If it is, clean or replace it. If it is okay, then remove the EGR inlet tube from the exhaust manifold and the EGR outlet tube from the intake manifold. If either or both are clogged, clean them out or replace them. Then check the ports in the manifolds themselves to see if they are clogged. If so, clean them out. When you are done, disconnect the battery for about 30 seconds to clear the code and drive the car to see if the light comes back. This should take care of the problem. If not, then you will need to put a scan tool on the car and see what the EGR control system is doing wrong and correct it.
The Valve on this car is electronic, so, unfortunately a vacuum pump will not work for testing.
If you have a scan tool, you can command the pcm to open the valve to see if the valve itself is working.There are really only4 things to go wrong with these things, PCM, wiring,the valve itself, or plugged passages. I have never seen the pcm cause this problem, or the wiring for that matter. If you say you have pulled the EGR and checked the intake passages, then I would be pretty confident in saying the the egr valve itself is bad.
Thanks for using FixYa - a FixYa rating is appreciated for answering your FREE question.

Ad

Anonymous

  • 16 Answers
  • Posted on May 13, 2009

SOURCE: EGR problem

did u try cleanning out the lines connected to the egr they usually have a lot of hydrocarbon build up

freetek

Steve Allison

  • 5569 Answers
  • Posted on May 23, 2009

SOURCE: power loss

Can't answer your last question but catalytic convertors that are just not working anymore won't cause any loss of power. However, if they have shattered inside (they are kind of a ceramic honeycomb) they can dump junk into the exhaust system that can eventually clog your muffler or resonator.
Checking whether this has happened isn't difficult; after the warm up of the engine, either you or a helper needs to listen to the exhaust note. If firing of the cylinders is still distinct, the system isn't clogged with shrapnel; if it seems to hiss at higher RPMs, it is likely clogged.
This effect is easy to miss; I've had two failures and when cold, the engine would pull fine because the chunks of ceramic would fall to the bottom of the muffler and glue together somewhat. Once hot and agitated, they would clog the muffler and cause a severe loss of power but the idle would be OK. A hill that I would normally pull at 70 MPH, I couldn't top at all; had to sit and wait for things to cool down before proceeding.
It also seems some engines appreciate a bit of back-pressure in the exhaust system because the car gained in mileage and pulling power for several thousand miles before the clog became critical causing the mileage to fall sharply along with the power.  

Anonymous

  • 462 Answers
  • Posted on Sep 06, 2009

SOURCE: I have a 99 monte carlo with a 3.1, the check

Remove the air tube to the throttle body. Open the throttle all the way and look inside with a flash light. You are looking for a lump of carbon at the egr port int the intake manifold.

Remove the egr valve, using a hanger or stiff wire, clean out the egr port removing the carbon from the intake manifold.

Anonymous

  • 372 Answers
  • Posted on Sep 20, 2009

SOURCE: My 95 Chev. classic won't start. The pass key

Its not seeing the resistor in the key. Easy fix is under the dash you have 2 white wires in a orange casing. Cut that wire and the end that goes toward the fire wall and not the steering wheel strip the wires a bit. Now with a ohm meter measure the resistance in the key with the two metal strips one the key. Then go to radio shack and tell them what rreading you got and they will give you a resistor for it. Put the resistor between the two white wires and start the car....

Ad

Add Your Answer

×

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

0helpful
1answer

My 2005 Dodge Dakota is having issues starting, it would start a couple times but would idle then shut itself off, while driving would shut off as soon as I released (something??).

You ran 20 volts into a 12 volt system?!?! You exceeded the specs of the electronics by 6 volts, so you will have damaged electronic computer components. You will need an auto electrician with a pro grade $5,000 scan tool computer to diagnose what modules and sensors have failed due to the over-voltage.
0helpful
1answer

2003 trailblazer 4wd no crank no start. Engine light on. Security light comes on for a couple seconds then goes off when try to start. New battery. Fuses checked. Was starting ok & went in store, came out...

Engine light on. Security light comes on for a couple seconds then goes off when try to start ? You need to hook up a professional grade scan tool an do full vehicle scan ,all the modules on the vehicle . PCM - engine computer , BCM -body control module etc...

If you "trick" the starter, and turn key to start at same time ? How do you trick the starter ? jump the B+ terminal to S terminal on the starter solenoid or jump pins 30 & 87 at the starter relay ?
I can't afford to take it to dealer.? don't take it to a dealer , have mobile tech. come to you . Because you have not the knowledge to be messing with it.
0helpful
1answer

Ford tractor

How old is the fuel in the tractor? is it petrol or diesel powered?
0helpful
1answer

Tacoma power goes out when i hit brake

there is either a short in the switch or its grounding something out
0helpful
1answer

My 99 Taurus acts like the battery is dead it will crank the engine over a couple times slowly then nothing I've had the battery tested and it was good same with the starter it won't jump start...

If the battery and starter have proven good, then you probably have a connection issue.Check condition of battery, wire to battery, and starter wires and connections also. I dont know your particular situation, but there is always the possibility of a motor trying to sieze.
0helpful
1answer

My daughters 2006 chevy cobal wont crank the battery is fully charged . i tested the batteryit has 12.75 volts at the battery and at the jump start terminal under the hood i also connected a fully charged...

Sounds like the starter itself has gone bad. If you can access it easily you can try to jump across the solenoid. Use a jumper wire from the hot lead to the exciter lead. If your not comfortable doing that DONT. Im pretty certain your starter is bad.
0helpful
1answer

Ran out of gas, replaced gas try starting, wont

hit the key five times without trying to start, just bump the starter, after the fith time turn it over and it should crank
0helpful
1answer

95 Cavalier wont start without a jump after replacing starter

loosen the battery cable.... start the car with a boost.... after it is running... unhook the battery.... if it dies... replace the alternator... if it keeps running... replace the battery.... make sure this is done outside and everyone working on the car is wearing safety glasses
Not finding what you are looking for?

560 views

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

ZJ Limited
ZJ Limited

Level 3 Expert

17989 Answers

john h

Level 3 Expert

29494 Answers

Thomas Perkins
Thomas Perkins

Level 3 Expert

15088 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...