Throttle body cleaning issues EPIC Volvo saga...RESOLVED!!

sergio · Post by **sergio** » 13 Jul 2013, 13:26

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ECM A17 is connected to pin 2 of MAF.
When I checked pins for incoming voltage at ECM (with ECM removed) I had no voltage.
At B11 there was 12V.
Now I do have 12V on pin 2 on the MAF and I do have continuity between all MAF wires and CEM.
Doesn't this say that if I check the ECM pins from the back I would read 12V on pin A17 ?
Or are we talking about another pin / another page?

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draser · Post by **draser** » 13 Jul 2013, 16:18

That's the page, so it looks like you do have 12v getting into the ECM. How about the grounds at the bottom of the page - (going into ECM)?

sergio · Post by **sergio** » 14 Jul 2013, 05:59

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Sorry, I'm confused. You mean lines C and D ? or the three A:54 A:63 A:53 ?

It s curious they was I understand electrical drawings, when lines are connected and bundled between separate and similar elements it is indication that this is ground.
In this drawing (Engine management system) pin 1 of 8/6, 8/7, 8/9, 8/9, 8/10 and pin 2 of MAF are connected but pin 2 of these are independent. This looks like they are the negative, Ground. Yet I get 12V positive on pin 2 of MAF.
BTW are these 8/6,8/7... the injectors?

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draser · Post by **draser** » 14 Jul 2013, 06:43

The 8/n devices - which are the injectors - have a common "junction point" 53/315. The batt voltage from fuse 11/B6 gets there, and to pin 2 of MAF.
The grounds for ECM are at the bottom of diagram, A53, 54, 63 and go to junction point 53/325 and from there to car chassis at 31/96 (which is on left fender I believe).
So you were correct. There's a legend in the first pages of wiring diagram booklet the explains all that, also a list of ground locations in the car. I could not find a list of junction points.

draser · Post by **draser** » 14 Jul 2013, 06:45

Forgot about lines C and D, thay are positive batt voltage, one you don't have (dotted) the other (C) goes to pedal sensor pin 1.

Post by **mikealder** » 14 Jul 2013, 06:56

If you scroll down to the last two pages of the wiring diagram you will find a list of component numbers and descriptions which makes it easier to find out what is what.

Look at page 119 for a diagram of junction 53/315
Look at page 129 for the location of the junction in the engine harness, note there are two different locations for this junction depending upon 5 cyl or 6 cyl - Mike

sergio · Post by **sergio** » 14 Jul 2013, 08:40

Thanks for the eyeglasses

sergio · Post by **sergio** » 15 Jul 2013, 08:13

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I called a dealer (no names please) to ask whether they could test the ECM "just the ECM, I said.
Well, they "have a machine to test [that], they want the car over there, and they will charge me whatever time it takes to discover whatever it is" And of course I have to tow the car.
There goes my hope of having an independent look into the CEM.
Must be bunch of retired civil servants working there.

What if I added 12V via a needle to the back of 12V pin going into ETA?
Would that blow my garage?

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draser · Post by **draser** » 15 Jul 2013, 15:52

Can't apply straight 12v to ETA. How about having Xemodex test it, they can bench test it for correct voltages at ETA area pins?

Post by **precopster** » 15 Jul 2013, 16:05

The "machine" is Vida Dice. They just know the test points a little better.

Lucky from ARD can do the same thing without the car.

Be sure that whoever you send it to has the ability to clone a used ECM. I don't think dealers can do this; only initialise a nice shiny new one.

Throttle body cleaning issues EPIC Volvo saga...RESOLVED!!

Re: Throttle body cleaning issues