Chevy Impala SS Forum banner
21 - 35 of 35 Posts

·
Registered
Joined
·
2,099 Posts
Would one of these pins be better to use? This is only a guess, but right now I’m leaning towards using B16. Anyone out there more versed in electronics willing to give me any pointers?
I could not find any information on D27's ground.

What you could do is set up your logging software and use a battery pack to test if one ground is better than another.

Three AA batteries are usually 4.5-5volts but measure the pack before applying to the PCM.

Can you tell us what output the wideband uses? Is it 0-5 or1-4 or what.

The PCM reading 3.4V instead of 3.5 does not decrease accuracy if it reads the same way every time. What I think you are worried about is losing data range. IE 0-5V is better than if the PCM only reads the widband as 1-4V
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #22 · (Edited)
I could not find any information on D27's ground.

What you could do is set up your logging software and use a battery pack to test if one ground is better than another.

Three AA batteries are usually 4.5-5volts but measure the pack before applying to the PCM.

Can you tell us what output the wideband uses? Is it 0-5 or1-4 or what.

The PCM reading 3.4V instead of 3.5 does not decrease accuracy if it reads the same way every time. What I think you are worried about is losing data range. IE 0-5V is better than if the PCM only reads the widband as 1-4V
Thanks for looking into it.
Here is a graph of the WBlin output from the tech edge webpage (wbo2.com), 0 to 5v output.
Rectangle Slope Plot Line Font

I'll probably play around with the different grounds when I get to using this on the '95 just to see if it makes much difference. I don't expect the difference in accuracy will make any difference to me. All grounds are going to be close enough to 0 that I won't notice any error.
For the 2011, I'll be using the AC pressure sensor connector to log wideband. Pretty easy to know what ground to use there!

EDIT: I should also mention that this unit does not NEED to use the ground. There is a jumper on the board that ties WBlin- to ground. If this jumper is used, then it will just put out a single ended voltage output that can go directly to (for example) D27. If the jumper is left off, then it puts out a differential output and WBlin- will need to be connected to an appropriate ground as we're discussing.

EDIT 2: The more I read over the assembly guide, the less confident I am about this ground thing. I'm currently thinking I just want to install the jumper and run a single wire to D27 or the AC pressure sensor connector. The guide is here. The section related to this starts on page 19. For those smarter than me, feel free to chime in.
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #23 ·
The bottom of the lambda module has jumpers that must be set to match the sensor you are using. The website mentions these jumpers several times, but it took me quite a bit of poking around before I found an explanation of how they should be set. One jumper sets the module for Bosch vs NTK sensors. It is set to Bosch by default, so I left it alone. The second sets the module for the 4.0/4.2 vs 4.9 sensors. This was set to 4.0/4.2 by default and had to be switched for my 4.9. This is how they should look if you are using the Bosch LSU 4.9.
Camera accessory Electronic component Font Circuit component Metal


The IC’s are all installed and the lambda module is screwed down.
Passive circuit component Circuit component Hardware programmer Microcontroller Capacitor
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #24 ·
The circuit board is installed in the case. Applied the sticker and some little rubber feet. That should complete the controller. I have the parts laid out to build the harness to the sensor. Not sure if I’ll get to that tonight or not.
Wood Font Rectangle Auto part Technology
 

·
Registered
Joined
·
9,004 Posts
Ok guys. You Made Me Look - Again!
I have not kept up, so have to catch up and appears to be rather detailed updates.
 
  • Like
Reactions: Jim Paley

·
Registered
Joined
·
2,099 Posts
I'm currently thinking I just want to install the jumper and run a single wire to D27 or the AC pressure sensor connector.
I think this guy's instructions have given me a headache.

Reasons why I think you are correct:
"The WBlin output voltage is a single-ended output as standard (J2 jumper ON)" From 12.3

"A. The default WBo2 configuration for WBlin+/- is shown in the image fig 7a.
This configuration is a single ended output with GND return. The internal shunt (ie. jumper) is ON so that WBlin- uses the WBo2 GND point as a reference."

Wideband Output WBlin
"The default linear wideband output mapping is shown in the image at right."(graph from post #22)

The different tunner sites mention D27 without mention of special grounding so I ASSume that battery negative not 5V reference ground is used.

If you look at the DTC 66-67 pages they show the A/C sensor input with it's separate 5V and 5V ground reference. The lore on this and other forums is that D12 has been used as a input with "common"(battery grounded) devices from what I have read. If it worked for others it should work for you.

If the 2Y is within inches of the PCM and you use a well shielded wire you are probably doing all you can.
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #27 ·
I think this guy's instructions have given me a headache.
I hear that! Every step I take, I have to spend 20 or 30 minutes poking around the website to see if I can find any differing instructions for the 2Y2 or a 4.9 sensor or a newer cable, etc.

Going to go with the single 0 to 5v output. I left the jumper off the board, but it is easy enough to add one at the output connector. I guess if I suspect any inaccuracies I can always try something different.
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #28 ·
The first end is on the cable. I didn’t take as many photos as I intended to, but here you go.
connector kit contents:
Wood Grey Font Automotive tire Material property


Connector pulled apart:
Water Automotive tire Circuit component Auto part Tire


Wires stripped back and tinned:
Hand Circuit component Finger Nail Thumb


Shield braid soldered to center pin:
Circuit component Bicycle part Pliers Electrical wiring Electronic engineering


Finished end:
Fluid Liquid Writing implement Office supplies Tints and shades


And connected to controller:
Material property Font Gadget Camera accessory Cable
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #30 ·
I saw somewhere in the instructions that building the harness may be the hardest part. I’m not sure why this would be, but I guess I’ll find out.
I was wondering if this statement would come back to haunt me. I now understand why building the harness could be considered the hardest part. The connector for the O2 sensor was miserable to work with. Now that I’ve done it once and learned a few things, a second one would be much easier. Hopefully a couple comments will help out someone else wanting to try this.

-The pins are pretty small and 4 of the wires are tiny. I was able to get a solid crimp to the conductor using my weatherpack crimper, but the crimp for the weatherpack seal is much larger than these seals. It did an “ok” job of starting the crimp and making the terminal ears round, but they were still too big to fit into the connector housing. Reshaping them with a needle nose went ok… just a very slow and careful process. It probably took me longer to figure out what was causing the difficulty in loading the terminals than it did to correct the problem. Also to note when working with the terminals: Cut them from the strip vs. bending them back and forth until they break loose. Bending them will leave a raised lip with sharp corners that will catch on the connector housing as you are trying to load/unload them.

-The 4 small wires have no strength to them. Any extra drag from an oversize crimp or slightly bent pin will prevent you from being able to push the terminal into place. The wires will just bend as you try to push them in. A tiny needle nose works much better than your fingers, but you must be careful with the insulation. I’m sure my deformed insulation will show up in some of my photos below. Bottom line: make sure your crimps are small enough and your pins are straight or you will have a rough time.

- The terminals are almost square. It is not easy to tell which way they install in the housing. Look at the pins in the mating connector on the O2 sensor to verify which way they go. As far as I could tell, they can be installed 180° off and still work just fine.

- The secondary lock comes installed in the connector housing and slides out through a slot in the housing. I did not recognize it as a secondary lock at first. I’ll show some photos below. If I were to do this again, I’d completely remove the lock while trying to load the pins.

- If the pins are hard to see in the open end of the connector housing, they are not yet fully seated. Also, when fully seated, the seals should disappear inside the back of the housing.

Now some pics:
Here are the pieces of the connector kit laid out with the cable:
Window Textile Wood Rectangle Grey


Cable stripped back and heat shink placed over the braid. If you don't put it on now, it will be harder to get it on later after messing with the cable and fraying the end of the braid. I ended up taking about another 1/4" off of the black outer cable to get more room to work with the individual wires.
Textile Wood Font Jewellery Office supplies


The first pin and seal crimped on. This crimp for the seal was not small enough even though it LOOKS like the seal is bulging a bit out of the crimp.
Water Wood Lake Boats and boating--Equipment and supplies Rope


All pins crimped on. This was still before I realized that the seal crimps needed to be worked farther.
White Light Textile Wood Grey


At that point my wife asked for help making some bourbon pecan pies. I was happy to work on something else for a while.
Food Kitchen appliance Gas stove Tableware Cooktop


More pics coming...
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #31 ·
After a couple sessions of trying to get the pins loaded, I finally got them all. Note the seals are not really visible in the housing.
Automotive tire Wood Grey Flooring Gas


Here’s the front of the connector. Note the pins are easy to see.
Communication Device Finger Telephone Adapter Car alarm


The secondary lock sliding out the side of the housing:
Hand Automotive lighting Finger Communication Device Toy


First layer of heat shrink. This one was under the braid.
Surveillance camera Automotive lighting Bumper Tool Gas


Braid pulled up:
Surveillance camera Camera accessory Fixture Gas Security


Second layer, over the braid.
Surveillance camera Camera accessory Cable Gas Audio equipment


And a final layer:
Plumbing fixture Gas Cable Audio equipment Camera accessory


This is what I’ve got so far:
Gadget Electrical wiring Cable Audio equipment Wire

Next I’ll work on a power harness to connect this to the 2011 and work on updating the firmware for the 4.9 sensor.
 

·
Registered
Joined
·
2,051 Posts
While I love DIYs myself, is there something this offers over say the LC-1's, which are cheaper? I think mine, with gauges cost about the same as just this controller. Just curious.
 

·
Registered
Joined
·
185 Posts
Discussion Starter · #33 · (Edited)
When these DIY kits came out, they were MUCH cheaper than the commercial units. That’s what originally caught my attention. Now there is not much difference; the commercial offerings are much more fairly priced.
The programmable narrow band output was very interesting to me. Not as much anymore. Probably never going to get around to lean burn tuning.
The main driver was really just the DIY aspect. I tend to build everything I can.
 
  • Like
Reactions: 91ss and 95wagon

·
Registered
Joined
·
185 Posts
Discussion Starter · #35 ·
Yeah, I got the kit around the first post date. You’re exactly right. But I think I FOUND these kits over 20 years ago. At that time they were cheaper than the alternatives. It was then that I had decided I’d like to go that direction. Once I made the decision, it is hard to change my mind. Add that to my slight obsession with DIY, and here we are.
 
  • Like
Reactions: 91ss and 95wagon
21 - 35 of 35 Posts
Top