I may need a new ECU

Any issues related to FORScan application

I may need a new ECU

Postby AdrianH » Thu Apr 20, 2017 6:43 am

I have an issue with the car in that it will not drive the vacuum solenoid that controls the EGR valve and turbo boost on over run. The valve never opens so the EGR is always shut, the ECU reports the issue and puts on the warning light.
I have checked wiring to the ECU plug and all is OK even tried another valve, so left with what could be a ECU fault.

Question is where are things like the Vin number and mileage stored, if I change the ECU will these get changed or are they elsewhere on other modules.

I can save the injector codes before the swap and with the extended licence enter my key chips, but the others not sure.

Can anyone think of tests I cold do further, if i connect the vacuum from the pump to the EGR directly, the EGR opens so I know that is OK.

Cheers

Adrian
AdrianH
 
Posts: 26
Joined: Sat Mar 14, 2015 10:03 pm
Vehicle: Mondeo, TDCI 115 PS, 2.0l Reg 07 build 11/06

Re: I may need a new ECU

Postby william » Thu Apr 20, 2017 12:32 pm

Is there battery voltage going to both valves
08 mk4 mondeo 2.0 140 bhp
william
 
Posts: 108
Joined: Fri Jun 20, 2014 7:41 am

Re: I may need a new ECU

Postby AdrianH » Thu Apr 20, 2017 1:27 pm

If I connect the vacuum to the egr vavle direct I can hear the valve open and the trace on Forscan shows the voltage output fine.

If I monitor the voltage to the vacuum vavle with just ignition on there is approx 9 Volts, but it is with out load as I use a Digital meter.

I did try a 5 watt bulb across the terminals and started the car rev and let drop the revs, as I drop the revs I would expect the bulb to light as that is when I would expect the EGR to open up on over run, the bulb would only just register a very dimly.
The resistance of the coil of the vacuum valve is 12 Ohms so I know a bulb would be safe as a temp check.

I managed to test the cables between the square connector from the ECU back to the valve and all metered out OK. What I may have to do is try and get the ECU out from under the dash and measure from the larger multi-plug back, but what a job that seems to be.

For information the turbo is one of the stepper driven type and I can see the actuator arm moving to and fro. Is there another sensor I could be looking for in the system I have missed?

Adrian
AdrianH
 
Posts: 26
Joined: Sat Mar 14, 2015 10:03 pm
Vehicle: Mondeo, TDCI 115 PS, 2.0l Reg 07 build 11/06

Re: I may need a new ECU

Postby william » Thu Apr 20, 2017 3:19 pm

My car is a different year to yours so I don't know if it will help but if I measure voltage to the vacuum valves with key on it reads battery voltage, my the two vacuum valves are supplied voltage from the same fused spliced wire from engine fuse box, if you have the same setup then you should see battery voltage as well.
If you can get hold of a wiring diagram to see where voltage is coming from it could help.
My voltage readings were taken with the black lead of the multimeter on battery negative.
08 mk4 mondeo 2.0 140 bhp
william
 
Posts: 108
Joined: Fri Jun 20, 2014 7:41 am

Re: I may need a new ECU

Postby AdrianH » Thu Apr 20, 2017 5:46 pm

Mine car has only a single valve not two, so possibly a difference in years???

But it is a thought that there may be feeds off to the fuse box before the square connector, which fuse number is it in your car and I assume it is under bonnet and I will see if I have that fuse fitted?

Cheers

Adrian
Last edited by AdrianH on Thu Apr 20, 2017 6:29 pm, edited 1 time in total.
AdrianH
 
Posts: 26
Joined: Sat Mar 14, 2015 10:03 pm
Vehicle: Mondeo, TDCI 115 PS, 2.0l Reg 07 build 11/06

Re: I may need a new ECU

Postby clemo » Thu Apr 20, 2017 6:18 pm

Whats the reg I can get hold of wiring diagrams for you to check. PM reg if you like.
clemo
 
Posts: 20
Joined: Tue Oct 25, 2016 5:35 pm
Location: Gloucestershire
Vehicle: Mk3 Mondeo 2.5 V6 ztec s

Re: I may need a new ECU

Postby AdrianH » Thu Apr 20, 2017 8:30 pm

OK going on with a bit of help from clemo and a diagram and comments from william I have done a bit more digging.

Decided to again check volts, I am getting a typical reading across the solenoid of 9 Volts, so not battery supply!

In the fuse box I found two fuses that would kill the volts across the pins. F33 or F41 both killed the volts.

Looks like F33 supplies the relay that powers the whole ECU through K46 to K22 (two relays) and F8 the 60 amp feed.

F41 supplies Y28 ?? and Y217 (turbo) so I would go for it being Y28 is the valve.

More digging and the fuse supplies are good, from the Green with Blue stripe wire I have is a very healthy battery supply to chassis, but not between the green and corresponding wire for the solenoid. So to me it looks like the negative side from the ECU is not there, so either still down to a duff ECU switching transistor or a bad joint.

A quick look near the foot pedals and removal of the ECU could be this weekend, possible bolted bracket that keeps it in place not sure if it is a simple release and pull out the ECU or if it is held in place some other way. Anyone taken the ECU out???
Cheers

Adrian

car1.jpg
car1.jpg (36.96 KiB) Viewed 646 times

car2.jpg
car2.jpg (42.71 KiB) Viewed 646 times


The single solenoid and the EGR valve.
AdrianH
 
Posts: 26
Joined: Sat Mar 14, 2015 10:03 pm
Vehicle: Mondeo, TDCI 115 PS, 2.0l Reg 07 build 11/06

Re: I may need a new ECU

Postby william » Thu Apr 20, 2017 10:22 pm

Does Forscan show any fault codes, and egr duty cycle. The spec for testing the vacuum valve is with the car running there should be 10 volts or over across the solenoid connector.
Last edited by william on Fri Apr 21, 2017 10:36 am, edited 1 time in total.
08 mk4 mondeo 2.0 140 bhp
william
 
Posts: 108
Joined: Fri Jun 20, 2014 7:41 am

Re: I may need a new ECU

Postby blacklocks » Fri Apr 21, 2017 6:44 am

Pierburg's test procedure for EPWs is here:

https://az25411.vo.msecnd.net/pdf/5/pg_ ... en_web.pdf
blacklocks
 
Posts: 6
Joined: Thu Mar 10, 2016 1:12 am
Vehicle: Mondeo TDCi 2.0 163ps 2011

Re: I may need a new ECU

Postby AdrianH » Fri Apr 21, 2017 11:37 am

William, the error code I get is P0409
EGR Sensor Crcuit malfunction as it never moves.

Blacklocks thanks for that.

Adrian
AdrianH
 
Posts: 26
Joined: Sat Mar 14, 2015 10:03 pm
Vehicle: Mondeo, TDCI 115 PS, 2.0l Reg 07 build 11/06

Next

Return to General and Support forum

Who is online

Users browsing this forum: No registered users and 19 guests