No crank signal

[nsusammyeb]

v3.57 msnse, ford vr sensor, 36-1 trigger wheel, DIY autotune board

I've got signal at the sensor itself but no signal at J1 3,4

Continuity is good in the harness, Jumper on JP1,2 installed, r57 gone.

Trim pots have no affect on signal, I'm getting no rpm and nothing showing up on the tooth logger. I did have to reinstall firmware on this board, 029y.

msq attached.

2016-02-09_11.48.52.msq

[nsusammyeb]

I have signal at pins 1 and 24 on the db37. I've checked pin 1 and it is a good ground with the rest of the board. The bottom of r57 shows signal when using the board common ground. I'm not getting any rpm in tunerstudio whatsoever, no matter how far I adjust the trim pots.

[nsusammyeb]

I've attached a datalog, but can't find any issues.

2016-02-09_14.25.26.msl

[Matt Cramer]

Does it work on a Stim?

Have you tried the tests in these articles?

http://www.diyautotune.com/tech_article ... _index.htm

http://www.diyautotune.com/tech_article ... s_test.htm

[nsusammyeb]

I have tried the first link to no avail. I've got great signal from the VR crossing at zero but no rpm input. I'll try to troubleshoot using the second link. First I've seen of it.

[nsusammyeb]

Do I leave the jumper installed when I run 5v and ground to jp1? I'm also assuming that pin 2 of u7 is the one on the right in the middle?

[nsusammyeb]

I assume U7 pinout is like this:

1 5
2 6
3 7
4 8

That being said, with 5v applied to jp1 I have 5v at pin 2. Ground applied at jp1 I have .57v at pin 2. with nothing applied at jp1 I have .57v, all of this done with the jumper installed.

I'm not sure of the pinout, instructions are vague in that area.

[slow_hemi6]

Always either a notch at the top or a dot next to pin 1.
1 8
2 7
3 6
4 5

[nsusammyeb]

Always either a notch at the top or a dot next to pin 1.
1 8
2 7
3 6
4 5

You are correct, just verified it with the wiring diagram and meter. Thank you for your help!

I believe I found the issue is with U7. With 5v applied to jp1, I have 1.5v@pin3, 5v@pin2, 0.0v@pin1. I should have 3.5v or more at pin 1 and it's reading zero. However, when I ground jp1 I have 1.5v@pin3, .57v@pin2, 5v@pin1. So, it is changing although it's not changing as per diyautotune's instructions. Does it need to be replaced??

Pin 1 of u7 is going high when there is more voltage on pin 3 than pin 2, and low when vice versa, but it's reading 0v instead of 3.5v per diyautotune.

"Once you have adjusted R56, apply 5 volts to the input. You should see between 4.5 and 5 volts at pin 2 of U7, and between 3.5 and 5 volts at pin 1 of U7. The MC34072 should be closer to 5 volts; older kits that used the LM2904 may be closer to 3.5."

I am reading zero volts during this test.

[8byah6]

I have a car doing the exact same thing scope shows signal coming in and going out but nothing in logs or ts. been reading up with no luck so thought i'd bump ya up

[turbothis]

VR sensor, so you are using what for the square wave input?

[jssteinke]

Ever get this figured out? My u7 has 0v on pin 1 with vr input high and 5v when grounded. I ordered a new u7 so we'll see if that changes anything. Scoped the vrin and I'm getting signal there but nothing comes out of the vr out

[jssteinke]

Replaced u7 with lm2904 temporarily. Output is still not what it should be. Grounded with trigger level set to ~1.5v pin 1 is at 3.x volts or high. I noticed between vrin and ground there is 5v. This isn't correct is it? It's acting like there's a pull up there but there shouldn't be one afaik.

[jssteinke]

Hopefully someone can clarify these statements for me from the points test for the vr conditioner.

The output (pin 1) of U7 is high when you have more volts on pin 3 than pin 2, and low when you have more volts on pin 2 than pin 3.

According to this statement:
0v pin 2, 1.5v pin3(trigger threshold) --> output high
5v pin2, 1.5v pin3 --> output low

Next, ground the input pin. This should give you from 0 to 1 volts at pin 1 of the U7

According to this statement:
Pin 2 0v, pin 3 1.5v --> 0v (output low)

Do these statements contradict each other or am I missing something.

According to the schematic the vr comparator circuit would be setup as inverting so the first statement would be correctly describing how the u7 circuit works?

[slow_hemi6]

Replaced u7 with lm2904 temporarily. Output is still not what it should be. Grounded with trigger level set to ~1.5v pin 1 is at 3.x volts or high. I noticed between vrin and ground there is 5v. This isn't correct is it? It's acting like there's a pull up there but there shouldn't be one afaik.

Pin 1 should be high If the Negative input is set at 1.5V and the positive input is Higher, which it should be because it is connected to Vcc through R44 and R48 and the PNP ztx553 is not conducting as it's base is held high through R47 and R51. As you are testing it is most likely Vin will be unloaded as it is not connected to a sensor.
Yes there is a pull up in the Vin circuit it's R51. If Vin is unloaded then it will be at the same level as Vcc.