Question about Cars & Trucks
2002 suzuki wagon r+ 1.3 petrol i have a p0401 fault code insufficent flow i have removed and cleanedthe egr valve any other ideas ? are there any other suzuki models with the same egr valve? all help much appreciated
Hi there: In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.
Hope this helps.
In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.
Posted on Dec 06, 2012
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Posted on Jan 02, 2017
Hi, The EGR valve itself is on a set of flexible pipework - usually stainless steel - which runs between the inlet manifold and the exhaust manifold. The EGR actuator valve is pneumatically / vacuum operated by a solenoid valve, controlled by the ECU ( aka the brane). It's not usual for the EGR valve itself to fail, more likely the solenoid valve or its electrical connector getting dirty. If you google for VAG TDI N75 valve you should get all the info you could possibly ever need :-)
Hope this helps, D.
Posted on Jul 16, 2008
P1744 is probably the TC going on the way out. :(
P 340 is probably the sensor itself. Don't get the Dorman one if it is the OHV motor.
P 401 is probably a bad DPF EGR sensor.
Posted on Jul 26, 2008
The electronic EGR valve and solenoid assembly is attached to the rear of the left cylinder head ,
Posted on Feb 05, 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.
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Posted on Mar 18, 2009
You can try cleaning the EGR valve and passages with Seafoam. A bottle costs just a few dollars at any auto parts store or discount store. With the engine running, squirt/spray it in through the brake booster hose, or through the PCV hose. This will cause smoke to come out the exhaust. This is normal and will disappear after a few minutes. If Seafoam does not do the trick, then you can still disassemble the EGR valve from the throttle body and clean it with throttle body cleaner.
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Posted on Sep 12, 2009
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