Check Engine Lights Flashes-The Saga Continues 2/10

Topic: Check Engine Lights Flashes-The Saga Continues 2/10 (Read 11943 times) previous topic - next topic

Check Engine Lights Flashes-The Saga Continues 2/10

Reply #90 – March 08, 2011, 08:47:14 PM

Pulll apart your computer and see if anything is fried, bypass vacuum lines to everything but the map sensor and see if it gets better or not.

Check Engine Lights Flashes-The Saga Continues 2/10

Reply #91 – March 09, 2011, 01:32:49 AM

The Sig-Rtn wire goes to the self test connector without going through the 10 pin connector. Check what the voltage is there.

Check Engine Lights Flashes-The Saga Continues 2/10

Reply #92 – March 09, 2011, 11:02:32 AM

Just so anyone following can be aware of what I did, to eliminate confusion. The following is what Joel over at SBFTech told me. What I did, in regards to testing from the 10 pin connector is:

EVP wire is also routed through the 10-pin connectors (salt & pepper)......

You can disconnect the white one and check the EVP voltage at the EEC harness IGN ON. If the voltage at the EVP terminal is 0 vdc.... the short is somewhere past the 10-pin connector..... if not, need to trace back the 10-pin connector towards the EEC.

Check Engine Lights Flashes-The Saga Continues 2/10

Reply #93 – March 09, 2011, 11:03:37 AM

Quote from: Haystack;354892

Pulll apart your computer and see if anything is fried, bypass vacuum lines to everything but the map sensor and see if it gets better or not.

I will do that. Last time I was in there(2 weeks ago) nothing was, but I will check again.

softtouch- I will check the SigRtn at the self test connector too.

Check Engine Lights Flashes-The Saga Continues 2/10

Reply #94 – March 09, 2011, 03:58:45 PM

Quote from: jpc647;354926

softtouch- I will check the SigRtn at the self test connector too.

Check with the 10 pin connector both plugged and unplugged.

Check Engine Lights Flashes-The Saga Continues 2/10

Reply #95 – March 28, 2011, 05:23:19 PM

Did you ever check the signal return voltage at the test connector?
If you have the 3.8 volts there check 88cougarGT's thread in the Electrical Tech forum.
He found an open land pattern in the EEC circuit board and shows how to fix it.
The open land is the sensor ground (signal return).

Check Engine Lights Flashes-The Saga Continues 2/10

Reply #96 – March 28, 2011, 06:49:12 PM

Quote from: jpc647;354852

Question regarding that.I can only test it while running the KOEO test right? I'll run it, wait till its done, floor the accelerator pedal, then seeing the actuators are active, I can test by sucking air, the floor it again to check it without it activated. Tha'ts what you were trying to describe?

Now I contacted Joel over at SBFTech.com in regards to this too. The EVP wire runs through the white 10 pin connector. I have a correct VREF of 5.0 volts, and as SIG-RTN of 3.8/3.9. The SIG-RTN should be less than .67v. Therefore, I have a short somewhere. I unplugged the 10 pin connector and got 0v for SIG-RTN and VREF which according to Joel means the problem is after the 10 pin connector, which is sorta good news.

I cut the loom back last night to find one orange wire running from the harness spliced into two orange wires, one going to the TPS one going to the EVP. At first I thought this was my problem, but it appears to be how it's supposed to be. Now for the heck of it, I grounded this wire, and tried to run EOEO test, and the check engine light just stayed on and I could hear some actuator near the trunk clicking away. So I'm probably not supposed to ground that. But now I'm wondering if this orange wire is tied to the orange wire that we've had threads about, the one that some people ground, others dont, etc. I may try to temporarily ground it and see what happens. I'll attempt to look at the EVTM tonight and see if I can make heads or tails of it.

This is what I saw when I fried the SIG-RTN line during my trans swap. SIG-RTN was floating. I burned it out because I had used a 5spd computer in an automatic harness.
You can read about my misery here.

I had temporally grounded the line going to the ground pin on the TPS using a tombstone crimp and a spare piece of wire. It ran better, but still got fuel mileage and hanging idle issues. It only got better when I repaired the trace inside the ECM. You could theoretically do this on a non-swap car if you accidentally sent +12v directly to SIG-RTN without a load in-between. I thought it was only a problem with the EEC-IV mass air computers. I would run a continuity check between the ground on say the TPS and Pin 46 on the computer.