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

[draser]

I may be late, but it looks like some wiring troubleshooting is required, as suggested by Vida on page 3. Based on your fluctuating idle, the first symptom from the start, I'd go for the ground connection at the TB connector. That's easy to check with a digital meter and the wiring diagram. Also check the TB connector for corrosion or pushed-in contacts.
I looked at the wiring diagram, and there's a relay that powers the ETM, so I'd meter that as well make sure it has 12-14v constant and not fluctuating. Easy way to do that is to check for 12-14v at the TB connector. I usually stick needles in the back of the connector for access. I have made 2 short jumper wires with insulated crocodile ends - all Radio Shack - to connect to meter leads and needles at connector, helps in my troubleshooting. Also make things safer, you don't want leads to touch while you're measuring - may damage electronics.
Before I replace anything I try to make certain - as much as I can - that the correct input signals get to the module.
It's pretty hard to troubleshoot the ETM because of multiple inputs that need to get to ECM which controls the ETM. If any of the inputs are out of range the ECM goes in limp mode. Looks like Vida get's you the voltages and tells what to look for in the wiring (open, shorts, etc.) but then a multimeter is required.

[sergio]

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Mike, you mean disconnect the CEM and reconnect it?

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[sergio]

draser, what shall I be looking for?
TB can not be "not grounded". It is metal bolted to metal.?
There are 6 wires to the TB 2 go the ECM. Others go probably to pedal sensor etc
Which wire is supposed to show 12V

Test the wires when the connector is plugged to TB? Key on position II? Engine running?

The cable is too short.


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[precopster]

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Mike, you mean disconnect the CEM and reconnect it?

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Check both ECM and CEM.

Procedure is in your Vida.

[sergio]

Thanks Mike

Hooked Vadis and this picture is the screen print.

disconnected

fault trace TB disconnected.jpg (49.53 KiB) Viewed 1365 times

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remembered I had disconnected TB connector, so switch off / key off, reconnected and

the result was the same (I did click on update though)
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connected

fault trace TB connected 2.jpg (50 KiB) Viewed 1365 times

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Turned the engine on; some noise again and 3 seconds after the usual oscillating rev the engine stopped.
Can't try the CEM.

Tried 3 times, same thing. The engine needs Viagra to hold on even oscillating.
I laugh out of frustration. I limp, so does the car.

The wires that go to the connector are too short to work with. I may want to extend their length.
Can one buy the connector head only?

Thanks

[precopster]

Current status is in the Delivery Tab; not Unselected CSC. Also colour of the modules (black and white) shows they're not being checked.

About the earth yes it's bolted to the manifold but the circuit board may get its earth from the loom.

You really should check the fuses and relays in the engine bay. Fuse 6 handles engine management.

The loom and plug which provides power/signal to the throttle body has only 4 wires if I'm not mistaken so only 4 to trace back to ECM plug (1 of them may go to the fuse area and another to earth) Use a meter in the ohms range (0-200 is fine) to check continuity b/w ECM and harness.

Please throw up an ACCURATE list of codes.

[draser]

Like indicated you'll check the ground at the ETM connector, one lead you'll touch each contact and other lead connected to chassis. You should read 0 ohms when you found ground contact. That's with key off ignition. There are two ground "rows" at each shock tower, visually check for corrosion and make sure they're tight. The other test is to put meter on volts, key in pos 2, connector disconnected, test contacts for 12v. That'll most than likely be the voltage to the throttle motor. Then you can test wiring from ETM to ECM, key off ignition, both conn pulled, meter on ohms lowest scale, or autorange. Try to find a wiring diagram on the net, it'll have the pinout for both and it's easier to trace. Just out of curiosity, if you use your old scanner what faults do you read? Anything about the pedal sensor?

[sergio]

Today I started cleaning the cable to TB connector with the contact cleaner.
Then using couple of needles I tried to find any trace of resistance or voltage at the connector's point.
There was 5 V between 2 point and some 1.5 V and 2.5 V at different combination of points.
This was done by pushing a needle in the connector (as if it was the pin on the TB)
Then I went on checking the Vida and here are the results;

Parameters

parameters.jpg (33.04 KiB) Viewed 1350 times

Then ECU

delivery 1.jpg (140.59 KiB) Viewed 1350 times

And CEM
despite the lack of highlight it was on delivery!

cem delivery.jpg (128.11 KiB) Viewed 1350 times

I see that there is a "CEM missing communication with TB"
This is the very first time I see this code

So I need to make sure there is continuity between TB and CEM?
There are 6 wires on the TB cable 4 of which go to CEM.

Is CEM placed under the relay box which is under the steering wheel?

If it is I am doomed because 2 years ago, I was unable to remove it to check a relay.

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[precopster]

I think it's too much a coincidence that you have so many failed modules. Again ask XeModex if they will test your CEM for a nominal fee:

[draser]

Sergio,
I believe that's where the CEM is. You'll need to get in there and unplug the connector. Batt cable off before that. Then unplug the ETM connector. Get a wiring diagram - net. Locate the ETM and get pin numbers and where they go to. Locate the CEM on wiring diagram and get pin numbers coming from ETM. Then use ohm-meter on lowest scale and check each wire continuity from connector to connector. The ETM connector should have a ground pin as well. Check continuity from each ETM pin to ground. Also look at ground wires on left/right shock towers/fenders, one has the gnd for ETM the other for pedal sensor. I'd do this first being the easiest. They are rows of screws with gnd wires.