Engine ECM location and possible problems

[bstwilliams]

I have a 2000 Leganza and it died on me yesterday in the middle of the freeway on my way home from work. It has been studdering intermittely for about a month now, that led me to beleive fuel pump issues. I get the car towed home and hooked up my code reader and it told me that it could not communicate with the vehicle. I tried resetting the ECM with no success. The fuel pump wont kick on when I turn the key on. I dont know if its a fuel pump problem or the ecm!! I really need help.

[Daniel]

If not already done check all fuses.
The fuel pump is drived by a relay try to swap/change it. Finger feel it clicks.
Check with a test lamp that you have 12V at fuel pump connector (two thicker wires) for 2 seconds at ignition ON.

[Puddle31]

I remember reading a topic on a wire for the fuel pump that corrodes on the passenger side, near the ECM. The problem with the air conditioner drain soaking the passenger side floor creates the problem and for some reason the fuel pump wire is the one that corrodes. do a search and I am sure you will find the topic, and it tells you the color and location of the wire and how to fix it. if you ever had a problem with that air conditioner, there is a chance that could be your problem. Good luck

[bstwilliams]

I ended up changing the fuel pump and it still does not work. I am gettin 12v at the pump. What other reasons would the pump not work??

[Daniel]

If you have 12V for 2 seconds between contacts 2&3 (providing you have the same connector as on pic) each time you switch ignition ON than your fuel pump is defective.
Edit: use a headlight bulb as test lamp, not a voltmeter.

test-lamp n°.JPG

[bstwilliams]

Thanks for all your help. I now have a schematic to look at to determine if the cars ECM is defective. I work on airplanes all day and have a wealth of knowledge of how an engine works but most of what I work on doesnt have a computer to control fuel even if it is fuel injected. Please keep the help coming.

[Daniel]

Thanks for all your help. I now have a schematic to look at to determine if the cars ECM is defective. I work on airplanes all day and have a wealth of knowledge of how an engine works but most of what I work on doesnt have a computer to control fuel even if it is fuel injected. Please keep the help coming.

Well, fuel pump activity is quite crude on our Daewoo. ON for 2 seconds at ignition ON than ON all the time when engine is running. Quite simple to sort IMHO.

[bstwilliams]

Ok. I checked for voltage at the #2 & #3 and have no power when the ignition is turned on. Now what?

[Daniel]

Ok. I checked for voltage at the #2 & #3 and have no power when the ignition is turned on. Now what?

You'll try by-passing fuel pump relay contacts.

Ignition OFF.
Reconnect fuel pump.
In the fuse/relay box under hood remove the fuel pump relay.
You'll see 4 contacts in a rectangle pattern.
With one wire of your test lamp (12V/55-60W) grounded locate the contact that have permanent 12v. That's contact #30.
Now place your test lamp between this #30 and the one located in diagonal. That's contact #87.

Does the lamp light?
Do you hear the fuel pump?

[bstwilliams]

How about a recall?!!? Apparentl there is a recall out for the stock cam position sensor. The sensor on my car was never replaced and I didn't know about it because Daewoo is no longer a motor corporation.

My cam position sensor melted and I had to engineer a system to get it working again with the help of a friend. We bought the new sensor and the car now runs. Try checking the cam possition sensor if you have a problem with your car.

[Daniel]

How about a recall?!!? Apparentl there is a recall out for the stock cam position sensor. The sensor on my car was never replaced and I didn't know about it because Daewoo is no longer a motor corporation.

My cam position sensor melted and I had to engineer a system to get it working again with the help of a friend. We bought the new sensor and the car now runs. Try checking the cam possition sensor if you have a problem with your car.

Is this in relation with your non priming fuel pump problem?

[bstwilliams]

Yes. My friend and I got out some schematics and determined that the inertia switch was tripped, the ECM fuse was blown and that the fuel pump relay was good. So that left the cam position switch. Replaced the switch and turned the key on and the fuel pump started it's 2 second cycle before engine start. So the problem I had was resolved.

[Puddle31]

great! Glad you got your problem resolved. yes, that was a recall for that car. there were "some" defective CPS. i called on mine and they said mine was not effected, however they were lying through their teeth because the only way to tell if you had a bad one was to take it off and look at the number on the sensor! I kept getting codes from mine and just went ahead and had it replaced and everythign cleared. glad you got your car running again.