Fitting the EGR Cheater

[curious]

Hi Vocky,

I know this is a vx220 forum, but I found this page through a link when looking for ways to disable the EGR on my Corsa C. Obviously, it won't work as-is, but hoped that if I understood what was going on, then I'd be able to adapt it to my engine...

Checking through the Haynes manual, the connector for the Z12XE is different, which isn't a suprise, although the connections you list for the Z16XE seem to match the Haynes manual for the Z14XE. So from my understanding of the diagram:

• Pin A is the pin from ECU that drives the valve open/shut (inverse of z22se pin E)
• Pin B is ground (assuming brown = ground) (pin A on z22se)
• Pin C is the EGR output (pin B on z22se)
• Pin D is 5v (seems to be connected to +ve on camshaft sensor) (pin D on z22se)
• Pin E is 12v (not connected on z22se)
• The relay is used to drive the input to the top left diode to 0v when A is 12v and to 12v when A is 0v

However, I'm a bit confused by what the final voltage at C would be and why... My understanding of electronics is almost 20 years rusty now, but this is what I think is happening:

• The Zener seems to be making the voltage at C a maximum of 4.7v, except I'm not sure what the 1k5 resistor is for.
• After the diode on the top right, you have 4.3v going through the 3k3 and 11.3v or 0v going through the 4k7.
• Is the resistor in parallel to the Zener to reduce the voltage? Does that mean that the voltage at C is 3300/4800 * 4.3 = 2.95v or 4700/6200 * 11.3v = 8.56v (limited to 4.7v) depending on the input at pin A? (I'm not really sure how diode and resister in parallel work)
• What's the point of the 5v through the resistor to generate 2.95v as the "low" value - is it just to protect the bottom diode? Otherwise when the relay was providing 0, presuming that would be fine too?
• This variable voltage is used to simulate different readings when the valve is open/shut, presumably when the ECU is making sure the EGR is connected correctly.
• Am I completely off track?

I guess after that, I'm on my own, but it looks like for the Z12XE, I can map A-1, B-2, C-4, D-3, E-5 on my EGR connector. I'm not sure how I determine if I need to use the relay, although I can always try both ways I guess...

Also, sorry for cluttering this by asking questions that aren't directly relating to the Z22SE, but this feels so tantalisingly close to what I need and I guess if you explain how the circuit works then all the vx220 owners will be more in the know too...

 

[vocky]

the 1k5 is because the z22se ecu wants to see roughly a 1to 5v signal, so the 1k5 gives about a 1.2v I think

so yes the 1k5 is to limit the voltage of the output signal

 

[rageous]

Hi Vocky,
I have a Renault Clio 1.9d and there is the EGR valve 7.22818.02. I'm wonder if this EGR cheater can work here. Could you take a look at link below, it's a tech documentation from Pierburg and check if it's possible to attach your EGR cheater, and what are right pin connections then ...
http://www.ms-motor-service.com/ximages/PG_SI_0085_EN_WEB.pdf

Thanks,
Tom

 

[vocky]

it's possible notsure.gif

CLIO - EGR cheater
pin 1 - not used
pin 2 - PIN D (blue)
pin 4 - PIN A (white)
pin 5 - PIN E (red)
pin 6 - PIN B (yellow)

 

[rageous]

Vocky,
you are magician
it's working in Clio. After some voltage tests I decided to attach it to connector. 90KM later 'check engine' led on dashboard turned off ... when EGR was connected it took ~90KM to turn off the light too so seems to be OK with your cheater

 

[MikeS]

pmsl vocky is going to be the scourge of dealerships at this rate, depriving them of their £100 EGR sales

 

[Matt]

He'd make a killing if he could sort one for the Z19DTH

 

[rambojack]

Hi there,
I am just trying to use this cheater on x18xe1 engine (Vectra B).
I made circuit according to this schema -

When I am trying to simulate -
pin A - switchitching between ground and +12V
pin B - ground
pin C - output
pin D - connect to +5V
pin E - connect to +12V

Circuit is working as follow:
When A= +12V, relay is off and there is only 5V power and between pins C and B is 1,5V.
When A= 0V, relay is on and there is between pins C and B 2,7V.
According to my knowledge of electronics it´s working as I expect.

I also tried to measure EGR connector (engine idling).
There is between pins E-B +14V, D-B +5V, E-A +10,2V, pins C and B looks as ground.

It looks that wiring of my EGR is same as wrote "curious" above.

But when I connect cheater, the ECU indicates error and when I diagnose failures, there is
1405 (EGR valve) and 0403 (EGR valve - voltage is too low or high).
There is only one change with cheater. After get started engine the "ECU indicator" is light off for about one
second. Without cheater indicator is light on all the time.

Any advice please?
Do you have some materials about function (and voltage which is EGR expecting)? It would be
very helpful for me.

Thanks a lot for any hint, Michal.

 

[vectra22]

HI, im quite new to this site n was recomended by jatie150 to get 1 of these egr cheater, to stop the problem of my enigne light coming on everytime.. i have got op com to clear it but just keeps coming back.. What gains will be from fitting this egr cheater??

 

[vocky]

the gain is no eml and you don't need the egr valve anymore - once you fit the egr blanking plate from the dealer £3.50

 

[vectra22]

Got my egr cheater monday just gone, n hopefully get it fitted today..

Big Thanks to Matt n Vcoky for getting the items sorted very quickly

 

[astra1.6]

Hi

Some time ago I started to have EGR malfunctions (engine check light) in my 2001 Opel Astra-G 1.6-16V (Z16XE) so I built EGR cheater according to instructions here. Unfortunately it never worked (maybe I built it wrongly :silent: ). When connected, after a while driving it again gave the same fault codes as with the faulty EGR-valve installed. Usually the EML light came on couple hundred miles after the ECU reset via disconnecting the battery.

In the last summer I carried out an ECU reprogramming to disable EGR functions while keeping the old EGR-valve connected. Since that I drove 10 000 km without problems, until the engine fault light appeared again with the familiar fault code 1405 (EGR).

I reset the ECU by taking off the battery for a couple of minutes. Then tested driving without EGR connected at all, but the engine light went on right away. So, obviously ECU still needs EGR-valve to be connected somehow :think: .

After that incident I reconnected the faulty EGR-valve again, and since that I drove at least couple of thousands kilometers until the EML light went on this morning (anything to do with the winter temperature of -22 Celsius )

Is it that even with EGR disabled in the ECU, the valve must be connected and functional?

To check whether my EGR is broken or not I tried to check the readings of the valve:
I took the EGR off and measured resistances between wires:
wires A-E for a solenoid about ~6 Ohm (solenoind working when feeded 12V between A-E)
B-D 2.81 kOhm, independent on valve position roblem: .
pin C over range (>1 Mohm resistance) against to any other pin roblem: .

Does anybody know what these values should be like? notsure.gif

I still have the blanking plate installed, so based on the carbon formation (the plate is clean) I deduced the EGR-valve never opens so the ECU re-programming was at least partially successful. Every time I have disconnected the EGR-valve from the car I have also cleaned the valve properly, so the problem should not be that it only jams. Based on these weird resistance measurements, I could guess the valve electronics have lost.

If it is right that the Pin C is the sensor position output, and the reading between this and pin B or D should vary as the valve plunger is opened/closed, then it should be possible to emulate the EGR-valve with a very simple circuit, which may be build of couple of resistors because here in my case the ECU only needs to sense the EGR is in place and that it is closed all the time. So I'm guessing that I could solder there a fixed resistor with resistance matching the value with EGR-solenoid closed.
Now I only need to know the resistances. Unfortunately I'm not so good in electronics, but I think you guys here are



Thanks for any help available!

 

[rookee]

May i also use 1N4007 diodes instead of the 1N4001 ones? The reason is: my electronics supplier does not have them...
Sorry for this "stupid" question, but i'm no electrician...
Thanks for any help.

 

[vocky]

it's just the volatge rating would be higher, so they should be fine

1n4001 = 50v
1n4007 = 1000v

 

[adamjmb]

Hmm just fitted my cheater and now i get a p0405 EML which means "Exhaust Gas Recirculation Sensor “A” Circuit Low". Have I wired it up wrong? Would go out and take everything apart and double check but is absolutely p**sing it down and has been all day lol.

 

[vocky]

double check the wiring and clear the codes dunno..

 

[adamjmb]

i have a scangauge2 so clearing the code is easy.. however after double and triple checking all the wires are definitely going to the right places but the code still pops up

the code only comes up after starting the engine, once you clear it it doesnt come back again during the trip... maybe one of the components on the cheater isnt working?

 

[vocky]

did you leave pin C disconnected, this is the ecu 0 volt for the 5v internal power.

if thats ok then it could be your ecu runs a slightly different internal voltage, approx 1 in every 100 ecu's have this problem.

the fix is to fit a different size resistor to replace the 1.5K Ohm resistor.

I can send you a replacement egr cheater with the modification fitted

 

[adamjmb]

wow, I just have a very unlucky ECU? Yes mate pin C which is brown wire with a white stripe is left unconnected so it must be that i have a 1 in 100 ECU. My astra is one of the last (2004) so maybe that makes a difference i don't know/

Thanks for your help vocky and yes if you send the replacement cheater i would be v. grateful...

BTW how much do second hand EGR valves fetch :mrgreen:

Cheers

 

[delboy2028]

got my egr cheater on and all correctly wired up but my EML light is still on says EGR is fauly what shal i do'?