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GM Drive-by-Wire Throttle Body and a Haltech ECU

I opened the garage door and I could smell that the magic smoke escaped from the Haltech ECU from five feet away. :( Still have not finished the setup.
 
Ugh oh, what happened?

My current theory is that the stock coil pack draws too many amps for the Haltech ECU and fried that circuitry despite having over current protection. However, I am hoping that it is something else and the warranty covers it. It will be another two to three weeks until I find out.
 
How did you BBQ it? wiring fault? :explosion

I never heard of a coil ignitor before now despite working on vehicles as a hobby for fifteen years. It seems to be that brands such as GM, Nissan, and a few others that use them.(Immediate close families all have some form of AMC/Jeep/Dodge/Chrysler.) Basically, instead of having the high amperage circuitry for the coils inside the ECU/PCM they are a separate module. Haltech ECUs require an external coil ignitor, but do not mention that in any of their documents.

The replacement parts will be here probably the end of this week or the beginning of next.
 
Any updates?

Just got back earlier today(Saturday) from a week of helping an old friend move to Texas.(Plus looking at opportunities out there.)

Connections left: Fuel pump, fuel level sensor, and alternator. Going to work on it in the morning and hopefully start it up.

For reference, the alternator uses a 250Hz signal from the PCM.(My probes are badly compensated; the 240Hz is off.)

12volts.png


12volts-AC-on.png
 
I forgot about the C107 connector; the one the splices the engine harness to the body harness. Basically a bridge between functionally on PCM connectors C1/C2 and C3. I spent a few hours today digging through it to find out which connections to keep.

What I narrowed it down to:
C107
  • 3 - Brown/Yellow - Sensor Ground(Full Level/Battery Temperature)
  • 6 - Orange/Dark Blue - TPS input to TCM
  • 8 - Black/Red - Part Time 4WD switch from Transfer Case
  • 9 - Black/Tan - Ground(May not be needed.)
  • 13 - Black/White - Full Time 4WD switch from Transfer Case

I also need to add a circuit to my CCD to CAN bus converter to output a 5V TPS sensor signal to send to the TCM. Though, I have idly been writing down specifications for building my own TCM with an Arduino that communications over CAN bus.
 
I forgot "2 - Dark Green - Alternator Field Driver" on C107. Kind of important! I realized I was looking at the wrong wire at the original PCM location. There are two "Dark Green/Orange" wires at the PCM. One is the output from automatic shutdown relay and the other is the alternator field source. It would not have been a big deal if they were mixed up, but it could result in potentially over or under voltage.

I worked on the power supply for the CAN to CCD bus translator as well. With that finished I can start testing in vehicle. It now includes a Digital-Analog Converter to provide a 0-5v analog sensor output to the TCM.

No pictures today. I am being rather busy during the week and weekends so my progress is slow. If that was not already obvious.
 
I have been tidying up the wiring harness before doing the final application of split wire loom sheathing. Putting a single wrap of electrical tape around the wire bundles every six inches helps to keep single wires from pushing out or escaping from the wire loom due to vibration.

I will have to call Haltech tomorrow to have a lengthier discussion about how their alternator field control works. I have the necessary battery voltage and DPO wires separated to hook up to the field wires, but I am worried that it may full field the alternator.

The three loose wires next to the speedometer sensor are for the transfer case switch. The connector and switch for that is still in shipment. I never fixed that when I swapped from a NP232 to a NP242. The two unfinished connectors are waiting on confirmation on the alternator control setup.
IMG_2202.jpg


Future thinking: The "BOOST CTRL" connector has two DPO wires and a battery voltage wire to hook up to a boost control solenoid. The engine from my LJ with the torn up camshaft is sitting elsewhere being used for exhaust manifold mock up.
IMG_2203.jpg


IMG_2204.jpg
 
I have been diagnosing a power issue for the fuel pump on and off the past week. There was power at the relay terminals, but not at the pump. After some more careful looking I found that clip in the PDC that holds the power terminal on the relay had broken off. However, the terminal was under spring tension from the wire.

Push relay in: Terminal gets pushed away; terrible connection.
Pull relay out: Terminal pops back up looking like it is seated correctly.

Disclaimer: I do not know if the OPDA clocking is correct, but it is close. My timing light I just bought refuses to work. Also, this is the first start with no tuning done.

https://www.youtube.com/watch?v=WRMzCrMOCMo

 
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