Rescued a wounded Bird
09-23-2017, 11:32 AM
#141
Resolved... probably Tentatively going to say it's resolved. But not how it thought it would be.
Yes, the harness needed to be replaced due to the hidden issue with the TCC solenoid built into the harness. But that wasn't the cause of the code 84 3-2 downshift circuit problem that kept it in limp mode. I replaced the harness, buttoned it up, filled it up and crossed my fingers. I used GaryDoug's Scan9495 utility to monitor for trouble codes and the code 84 almost immediately popped back up. I'd clear it and it'd come right back in 2-3 seconds. Looking at the electrical faults tab in the program, it made me think from another direction when it said 'open circuit' on the 3-2 downshift solenoid circuit. I have a spare PCM...
The spare was from a 94 Z28 with 3.23s. So I threw it in and fired it up and scanned again. No codes, no circuit faults. The current PCM threw the code 84 under both 94 and 95 calibrations. I ran it for almost 20 minutes on the spare- no codes, no faults. Ok, so I can't use a 94 tune on a 95 trans. My 16210041 calibration ID on the PCM I've been using all along has the 95 code and some small mods for O2 relocation, etc., and has good data. Could the PCM internal circuit traces for the 3-2 circuit be damaged?
I set up my flash bench and uploaded the tune to the spare PCM with EEHACK 4.7
. Threw it back in, crossed my fingers and... no codes. took it for a run around the block. Amazing to feel first gear in D at normal line pressure. I'll take it for a longer drive later and see how it goes. But it's never run for more than a few seconds before throwing the code 84 and now I've had 2 run cycles of nearly 25 minutes with no DTCs. I never considered the PCM might be at fault.
The mail order tune I got in 2010 was useless garbage and the reflash was good money after bad but it put me on the track of finding the hidden TCC solenoid problem and I learned more about the 4L60E. Way more than I wanted to actually, but it was good to learn.
Yes, the harness needed to be replaced due to the hidden issue with the TCC solenoid built into the harness. But that wasn't the cause of the code 84 3-2 downshift circuit problem that kept it in limp mode. I replaced the harness, buttoned it up, filled it up and crossed my fingers. I used GaryDoug's Scan9495 utility to monitor for trouble codes and the code 84 almost immediately popped back up. I'd clear it and it'd come right back in 2-3 seconds. Looking at the electrical faults tab in the program, it made me think from another direction when it said 'open circuit' on the 3-2 downshift solenoid circuit. I have a spare PCM...
The spare was from a 94 Z28 with 3.23s. So I threw it in and fired it up and scanned again. No codes, no circuit faults. The current PCM threw the code 84 under both 94 and 95 calibrations. I ran it for almost 20 minutes on the spare- no codes, no faults. Ok, so I can't use a 94 tune on a 95 trans. My 16210041 calibration ID on the PCM I've been using all along has the 95 code and some small mods for O2 relocation, etc., and has good data. Could the PCM internal circuit traces for the 3-2 circuit be damaged?
I set up my flash bench and uploaded the tune to the spare PCM with EEHACK 4.7
. Threw it back in, crossed my fingers and... no codes. took it for a run around the block. Amazing to feel first gear in D at normal line pressure. I'll take it for a longer drive later and see how it goes. But it's never run for more than a few seconds before throwing the code 84 and now I've had 2 run cycles of nearly 25 minutes with no DTCs. I never considered the PCM might be at fault.The mail order tune I got in 2010 was useless garbage and the reflash was good money after bad but it put me on the track of finding the hidden TCC solenoid problem and I learned more about the 4L60E. Way more than I wanted to actually, but it was good to learn.
09-23-2017, 07:34 PM
#143
Long damn thread, old damn thread, lol.
This car project came to a halt where it did in early 2011 when I met my wife and spent most of my time with her, we got pregnant in April 2011 and so family came first. The car shuffled from place to place within a 25 mile radius since then and has been sitting next to my garage for the last 6 months. Briefly had a place with a dedicated garage but we moved back to the neighborhood due to problems with the house we were buying last year. Started a 400HP TBI truck project last fall, red car waited again. Wife is now working out of town 5 days a week so late evenings are free to do whatever during the week. I cleaned it up again and brought it in the garage and I swore I was going to fix it once and for all or go ahead and offer it up locally for the first $800.00.
I just drove the **** out of it in the rural area I live in, east of Raleigh, NC. very gratifying. Now I can let it go and let someone finish out the project. It needs 2 tires, dash pad and paint and then maybe a y pipe & catback. Right now it has dumped duals and no cats since it was originally meant to be a track car, very low ground clearance. I'm thinking I'd like to get about $1600 out of it and let it go. Split the proceeds between my green M6 and the truck.
This car project came to a halt where it did in early 2011 when I met my wife and spent most of my time with her, we got pregnant in April 2011 and so family came first. The car shuffled from place to place within a 25 mile radius since then and has been sitting next to my garage for the last 6 months. Briefly had a place with a dedicated garage but we moved back to the neighborhood due to problems with the house we were buying last year. Started a 400HP TBI truck project last fall, red car waited again. Wife is now working out of town 5 days a week so late evenings are free to do whatever during the week. I cleaned it up again and brought it in the garage and I swore I was going to fix it once and for all or go ahead and offer it up locally for the first $800.00.
I just drove the **** out of it in the rural area I live in, east of Raleigh, NC. very gratifying. Now I can let it go and let someone finish out the project. It needs 2 tires, dash pad and paint and then maybe a y pipe & catback. Right now it has dumped duals and no cats since it was originally meant to be a track car, very low ground clearance. I'm thinking I'd like to get about $1600 out of it and let it go. Split the proceeds between my green M6 and the truck.
