Code 42 ...

I am trying to finally make my car drive able.

Previously I had an intermittent code 42.

I checked values, est wire values match. I do have slightly higher resistance reading after the translator, but less than .1 ohm difference. Voltage checks out.

Bypass wire, they do not. Have .5 v with koeo. Doesn't change with engine on.

With the ignition module connected it shows ground, but with resistance. Was using my power probe as it has longer leads than my dmm, so was just blinking GR rapidly.

I am assuming the values on the chart are correct @ 4.5v for the bypass, but I have nothing.

I am not sure if the bypass is supposed to have a specific resistance value when connected to the Ign module, but I would assume so.

Edit: Nvm, found the value. Not the issue. Still a voltage issue.

I am assuming this is pointing to an ecm issue?

Is there something that commands the ecm to send voltage to the bypass wire that could be causing an issue?

Thanks for any assistance. Trying to debug my car. Been an uphill battle with wind, and icy terrain.

I did try to search, but the search function on here seems to only show posts not grouped in threads, so kept coming to several of the same threads where I found the pinout, but didn't find anyone with low v on the bypass.

For the voltage reading I was using my dmm, so not just an off reading from the PP.
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Use Google for search, turbo buick code 42
Why didn't I think of that.... o_O.
(Sarcasm). Lol.

I did. Didn't really come to any "If this, then that". Like if no voltage on bypass wire, then XXXX is your issue. Mainly issues with the est wire/harness. Nothing that says anything about if you don't have voltage on the bypass. Searched Google, here, and turbobuicks. All of it pointed to the same pinout diagrams. Nothing says what commands the ecm to put 4.5 volts to the bypass wire.

Found a lot of the est issues are due to faulty modules. The est doesn't seem to be my issue, nor the module or coil pack. Unless I am missing something. Have replaced them anyways, but same issue.

Found the crank sensor was rubbed a while back. That got the car out of limp mode.

Had a calpak error, cleaned and re-seated the calpak chip, that issue hasn't came back yet. Found how to adjust the iac, fixed that issue. Unrigged the hotwire kit too.

Just keep having 42 issue now.

Have cleaned the contacts for the ecm too.
you mention the translator in relation to the EST, bypass, and code 42. Do you have a Translator Plus? If so, disconnect the timing control wiring, and reconnect that all stock.

Thanks Bob, I will do that tomorrow.

I assume the est wire to translator plus only controls ignition timing changes through the translator.
Well, definitely found an issue. The guy who built it only caught 2 of the strands when he connected the est wire to the translator. I started tugging and it came off with only one wire strand still inside it. For now I just used some sealed m/f terminals (spade), with heat shrink and low temp solder (supposedly). I have used them a lot, the heat shrink holds the wire solid to the crimp. Not the best case, but it's what I had, and all I had room to do. Not enough wire in there to reach back together, and didn't have any wire at home.

Odd thing is before I found that, tested both ecm outputs with my dmm using my extra long lead set and had voltage on the bypass wire today. I can only guess it is low enough signal voltage that the power probe draw was too much. If you haven't used a PP, it lights green for ground and red for power. I have a Snap-On digital test light, and it caused the same thing on signal only voltage in a few other efi applications I had encountered in the past.

Was able to brake boost the car without the code popping up. Previously that was all I needed to do to have it pop a 42. Couldn't really drive it as one of the drag bag lines is still kaput, and I drained all but about a gallon of fuel as a new fuel pump should be here tomorrow. Almost no fuel, and only one bag with 28x12.50 tires is not a good situation to try to drive with.

Thanks to everyone for the help :D

I will also say that Airlift is a great company. Contacted them as the lines got all puffy and kept popping off, and it looked like the fitting on the one bag was fubar. They sent an entire new kit for free.
Ok, so code came back. Was gone, but is no more... This was Sunday. It rained saturday, so I figured something to do with moisture.

I swapped the maf and a/f, then the code came back.

So tonight I finally had a chance to poke around.

I remembered a few years back I was told that there are 2 grounds on the pass head.

Then I read that there were 2 ground lugs, which I only found one with 4 wires going to 2 terminals. Looking back, I was told there was 2 grounds, which I guess there are 2 ground locations, and 4 wires... Which I guess was my issue, as I saw 4 wires with 2 terminals on one bolt.

Long of the short, tonight I started really reaching down and found 2 terminals hidden in the loom.


I couldn't really reach from the topside, so I shoved my crippled ass under the car, attached a jumper with gator clips, and wouldn't you know it, the damned cel/code is not popping up.

So my question is, how could the car have ran ok for a while, even a few hours one night without any issues?

Are these just redundant grounds, or could it just take time before something got pissed off enough to cause an issue?

What all is grounded there if anyone knows?

Really hoping this is my issue as I wanted to find it before swapping injectors/chip and still possibly having an issue.
there are very detailed ground schematics in the shop manual. I can dig mine out and go thru it with you, but you should really have one....

I guess I need to find one hahaha. I tried searching for generic manuals, but what I found locally mainly centered on the NA engines.
Well, it was a mother scratcher getting up to the grounds. I couldn't get the wires to reach the second hole in the head, nor could I fit a bolt in the far outside hole. I put them all on the same bolt, and seems to have fixed the issue.

Now I have a wastegate actuator issue, as well as an exhaust leak which I need to tend to sometime, as well as a bunch of oil leaks... The studs are so rusty @ the turbo that I feel they will break off.

Baby steps.

Thanks for the help.