Crazy ECU or limp mode?

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Re: Crazy ECU or limp mode?

Postby steevegt » Thu Nov 03, 2016 6:46 pm

I don't know if I can post wiring diagrams in here... It will be easier to explain.

But, from the wiring diagram that I have seen, you have 3 feed wires and 7 ground wires to the ECU.

E22, A31, B1, B8, B17, A21 and A30 are all ground pins on the ECU.

E1 is a feed wire on the ECU, always hot.
E2 is another feed wire, hot when ignition switch in position 2. (If it was me, I will start to scope this one)
E16 is a feed wire, hot when the ECU commands a relay.

Have you scoped all those pins, and validate that all the feeds/grounds to the computer are ok?
If you didn't I wouldn't consider doing anything before, except just that...
Just my opinion...
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Re: Crazy ECU or limp mode?

Postby STC » Thu Nov 03, 2016 8:49 pm

Victor
Your last waveform upload carries a lot of data, but the fault has not occurred within that capture.

As Steeve, I too have looked at wiring diagrams. I looked on Autodata Online which gives me 4 options:
2 or 4 Lambda Sensors, Manual or Automatic Gearbox. Which is yours?

I agree that you will have to scope all those power supplies and grounds from start to fault before you go further. Doubling the Supplies and /or Grounds would be fine to eliminate if you did not have a scope.

Have you checked the females in the connector, are they nice and tight on to the ECU pins ?

The permanent power supply to the injectors needs to be checked too.
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Re: Crazy ECU or limp mode?

Postby victor2k » Fri Nov 04, 2016 3:53 am

steevegt wrote:I don't know if I can post wiring diagrams in here... It will be easier to explain.

But, from the wiring diagram that I have seen, you have 3 feed wires and 7 ground wires to the ECU.

E22, A31, B1, B8, B17, A21 and A30 are all ground pins on the ECU.

E1 is a feed wire on the ECU, always hot.
E2 is another feed wire, hot when ignition switch in position 2. (If it was me, I will start to scope this one)
E16 is a feed wire, hot when the ECU commands a relay.

Have you scoped all those pins, and validate that all the feeds/grounds to the computer are ok?
If you didn't I wouldn't consider doing anything before, except just that...
Just my opinion...

Hello,
My car is RAV 4 with Automatic gearbox with 4 lambda sensors.
This ECUs are wellknown for harsh shifting issues and must be repaired/replaced
Also you can see in 0004 psdata a ECU current drop but nut voltage drop.
For earth points first I checked the continuity with ohmmeter-was 0,1 ohm betwwen ground points with ECU disconnected.
Now I recorded E1/E22,E1/B1,E1/B8,E1/B17,E1/A21,E1/A30,E1/A31:the voltage drop only after the disable of injection(charging of battery decrease).the injection is allways disabled when I have the issue on car,the ignition only some times.In the next step I will disconnect sensors from gearbox (fuel is cutoff at change of speed)...maybe the engine will start.
I will attach the unfiltered files
Thank you
Attachments
RAV4 AZ.rar
(11.44 MiB) Downloaded 5 times
0004 psdata.png
current monitored on E16 wire,voltage on E16/A21
0005 psdata.png
+15 from ignition switch E2/A21 was recorded:
0002 psdata.png
In the attached psdata.0002 was recorded the supply from main relay
E16 /A21 :
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Re: Crazy ECU or limp mode?

Postby STC » Fri Nov 04, 2016 9:11 pm

Victor
For earth points first I checked the continuity with ohmmeter-was 0,1 ohm between ground points with ECU disconnected.

That is not a good conclusive test !! Why not just volt drop all Grounds too with a scope, to see what happens as the fault occurs.
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Re: Crazy ECU or limp mode?

Postby victor2k » Sat Nov 05, 2016 6:56 am

STC wrote:Victor
For earth points first I checked the continuity with ohmmeter-was 0,1 ohm between ground points with ECU disconnected.

That is not a good conclusive test !! Why not just volt drop all Grounds too with a scope, to see what happens as the fault occurs.

Hello,
In the previous post I attached all 7 captures(archive RAV4 AZ) with e1(battery supply)/ground points(e22,b1,b8,b17,a21,a30,a31) when the injection dissapear.The drop of supply is not the cause but an effect of the charge missing(voltage drop from 14v to 12 v after the dissapear of injection) like in the attached image.
Thank you
Attachments
E1 vs E22.png
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