For more on Engine Performance Diagnostics go to my website at www.scannerdanner.com In this video I show another variable when it come to testing this type …
How to test an electronic EGR valve (GM P1406 case study)
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Bloody brilliant mate :)
Can anyone help out…I have a 1996 chevy express with the 5.0 and I have
been getting code P1406 and can not get rid of it. i have changed over to
MPFI since i was getting a misfire code and the old poppet injection system
was bad in the process of doing that i changed the upper intake manifold
and cleaned the lower manifold. the misfire code never came back but the
p1406 still comes back, i have installed over 3 egr valves and they come
back. I have taken the valve out and tried cleaning the ports with sea foam
and throttle body cleaner and the code comes back. Other parts that have
been changed are wires,plugs,cap,rotor,Catalyc converter, all 4 O2 sensors.
i am at a loss with this code..next thing would be to check the circuit
like the video? any help would be appreciated.
an alternative way to get a 5v ref to the egr is to use a LM7805 or a
LM7905 (different current ratings) three legged voltage regulator, which is
very similar to the voltage regulator in the ecu, run a lead to it from the
switched 12V, these can be bolted to the case of the ecu
What direction would u take to diagnose a egr excessive flow. The system
uses a maf, it has an egr temp sensor and solenoid. Any advise would great.
Thanks
ah! so cool.
Liked it . I enjoy your tips and knowledge. Thanks. Shop ownwer in CA
Scanner Danner… You sir are the man!
U the best. Really inspired by your videos
Glad i had this video brought to my attention. Having an issue with my 99
blazer p1404/p0405 tried 2x new OEM replacement egr valves + brought to a
local chevy dealer they had to call GM directly because they couldnt figure
out why it wasnt working. I check the wire harness and found the 12v red
wire for my EGR valve is not getting any voltage from the pcm.
well what can i say thats the best video and fool proof thanks for taking
the time to make it and posting it AAAAA+++++++ im going to look for some
more that youve posted thanks
oh I definitely have limits 🙂 Thank you!
never would have thought of using the meter as a jumper I would have gone
looking for power probe. great tip thank you.
It just keeps getting better…….Yipeeeeeeeeeeeeeeeeeeeeeeeee
Why 3 wires for a potentiometer? Seems a bit overkill. Pins can’t get loose
over time especially the older a vehicle gets. Thanks for showing a way to
test for that. Learn something new every video. When it comes to replacing
an ECU you’d better be sure, double-sure, and triple-sure. 😉
Yes. That is what I did in the video. I just did it at the computer side
instead of the sensor side.
you are the best scannerdanner !!
sick with it!
I think the only safe way to jump a wire and not cook the computer is to
know exactly what wire you are on and know the circuit design of that
circuit.
I already have and plan on passing the word to some of my fellow students
about it.
We need to be extra careful with these. For example, I have been playing
with GDI systems lately and the computer controls BOTH sides of the
injector circuit. But, with GM EGR systems, they changed it to power side
switching and only control the power side. The other wire is a constant
ground even though it goes to the computer. To ID which wire to energize,
take a test light to b+ and touch on control wires. The one that lights up
is the constant ground. The other is the switched b+ side
i use my scan tool in EGR override on digital EGRs to command it open to
about 90% and then closed while keeping the engine running with my right
foot on the throttle.. this has cured a LOT of 3 solenoid EGR valves and
stopped the pinging.. it also improved the throttle response and fuel
economy went way up as the dilution of the O2% in the incoming air charge
reduces the amount of fuel needed. this really is seen in open loop
acceleration.
Not sure yet. One thing I noticed is the buffer for scan data is now
limited? I used to be able to go back and look at an entire test drive with
a paused screen. It seems I can’t do this anymore? If so….that sucks big
time.
I’ve jumped similar ref wires several times through the years for ‘poverty
stricken’ customers… but only after thoroughly explaining that the mod
has to be at the customers sole risk. All were successful. Those welding
tip cleaners are a fairly common tool truck item… but they might be
tucked away in a drawer… ask you tool guy. Great videos, Thanks man!
That is correct. There is only one 5v reg. even though there were two
separate circuits coming out of the ECM. They are shared internally.
Awesome Vid! Here in Australia we have the same looking motor (3800 V6
Buick) in Holden Commodores, common as mud, this can apply to these motors
too. Super instructional, thanks ScannerDanner 🙂
No luck. Couldn’t hardly trace the circuit and didn’t see anything. I need
glasses! I am 40 now and just don’t have the vision I used to. Never needed
glasses before 🙂
Section 3 page 6 in my book my friend
i def aspire to b as great as a diagnostic tech as u r simply cause no 1
else wants to invest the time and money into the rite equipment to give a
thoro evaluation….Thank You for the inspiration! i will def b ordering ur
book soon, and def will continue to show u love on ur vids!!!!
Great, just like all your videos. You leave no stone unturned. Thanks for
sharing your knowledge with the rest of us. Joe
Well done!! Definitely a good point on the older GM computers going bad a
lot. It seems like the red, white, blue connector PCM’s like the one in
this video were the worst about that. It also don’t surprise me that the
new PCM also is bad cause you can find buried gold easier than you can find
a good red, white blue connector PCM. Good vid as always.
what all does “catalyst monitor” cover exactly?
yes it was and thank you!
So test light to B+, touch the wire that is grounded (EGR to engine block)
test light will light. What will happen if it touches the control wire?
Wouldn’t it light up as well?
This kind of high tech teaching is found only with scanner danner
people!!!!!
Thank you so much! Check your spam folder for an email I just sent you
about the ebook format
No problem, just be careful with it, as Bushougoma said. You must know the
current flow of the circuit you are jumping. Make sure it is well under the
10a rating of your ammeter. Otherwise you will blow the fuse in your
ammeter.
I sure don’t think its overkill. It only takes 1 time of misdiagnosing a
computer and looking stupid. I rather take the extra steps
thanks—-one of the best videos i have ever seen——-just great