I have been trying to figure this out for a while now. I have tried all the recommendations that I was able to find on this forum. I have 12.3 volts to both sides of fuses 24 and 31, fuel pump spools up when I jump 1 to 7 and 5 to 7. I have gone through the steps for checking the main relay and harness for voltage and continuity, harness checked out fine and relay was a little sketchy on one test so I replaced it and still nothing. Is there something I have missed or any other ideas to check?

 

Check ground wires on the thermostat. What do the CEL, oil and battery lights do when you turn key on and don't crank?

 

Do this test:

Unplug ECU connector A.

Turn key to ON(II).

Ground either pin A7 or A8 (whichever pin is attached to a Grn/Yel wire) to metal frame under dash.

Does fuel pump run as long as A7 or A8 is grounded?

 

Thanks for the quick replies.

I checked/cleaned the thermostat ground.

Oil, battery, and CEL all come on and stay on when key is turned to "on".

Fuel pump runs when I ground A7 (green wire with yellow stripe).

 

Sounds like the ECU is bad.

Replace it if there's battery voltage at ECU connector pins A25 and B1 and continuity to body at ECU connector pins A26 and B2.

 

Thanks, I will verify voltage and continuity at those pins and replace ECU if that checks out.

 

Swapping the ECU fixed it. Thanks again. Is a dead ECU (free) of use to anyone?

 

If the bad component can be identified, the ECU can be repaired. Are you saying you would send the ECU to somebody willing to pay for shipping?

 

If you want it I'll pay the shipping as a thanks for the troubleshooting help. Otherwise I'll meet someone near Raleigh or someone can send a shipping label and I'll send it.

 

I'll PM you.

 

meich75 kindly sent me his bad P06 ECU.

I removed the top and bottom ECU lids. The problem was immediately evident. Main capacitor C14, which supplies 5 reference volts to many sensors (e.g., MAP sensor and TPS), clearly blew and damaged the printed circuit board (PCB). The PCB must be cleaned up and the bad capacitor removed to see whether the damage is reparable.

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Thanks for posting your findings so far and the pics. Interesting to see that it was that bad.

 

that is a nice burn!