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Trying to time DS4, Can't connect to PCM...help!

D

DieselAmateur

She ain't revved 'til the rods are thrown...
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As the title implies, I'm attempting to set the timing on my 1995 K2500 OBD-1. I purchased the GMTD Scan Tech software and 12-pin to USB cable and have everything installed and connected.

When I attempt to connect, the following is displayed:

Initializing communication (green light)

COM3 Port opened at 8192 Baud (green light)

Could Not connect to PCM (red light)

COM3 Port Closed (green light)

Communication ended (green light)


By dumb luck, I went to the tools tab, hit settings, and changed the interface from echoing to non-echoing. This for whatever reason allowed the software to connect to the PCM and I'm told that ScanTech is ready for use!

However...

In the dashboard, I have zero readings. It seems that the PCM is still not relaying information to my laptop, as I just have - in all monitors. Without any readings, I cannot verify ECT or read base timing and then command the learn functions.

I'm going to restart my computer and see if that changes anything.

I've tried to change the interface back to echoing once connected to see if that would make the laptop get readings from the PCM, but it did not change anything.

I'll also note that the truck has an aftermarket chip from the infamous Buddy, but that shouldn't affect real time data collection correct?

If anyone has advice/ has encountered this before, please help!
 
She's running ok, as mentioned I really can tell the difference with the roller rockers. Highly recommended upgrade.

Truck is sluggish though, which I'm attributing to the poor timing. I'm tentative to run it too hard until its timed, but the only fellow around here that I've been trying to help me for months is at least another week away from being available...

Given my frustrations with the DS4 I'm tempted to just go manual, but seeing as how much trouble @spdgofast is having with finding a quality DB2 to match his P400 I don't know where to source one from. His experience with Conestoga is certainly off putting for me. Is John at uniquediesel still building pumps at all?
 
My obd-1 truck isn't here but I opened Scan Tech and it is set on "Echoing" Try a different USB port or a different COM port in settings.
 
NVW said:
Also the toggle on the adapter is supposed to be in the forward position
Click to expand...

What do you mean by the toggle? Adapter is usb and 12 pin like this one here

OBD Diagnostics, Inc. - OBD2 All-In-One Scan Tool w/ USB

The OBD2allinone pc scan tool to turn off the check engine light on OBD2 cars and trucks is made and sold by OBD Diagnostics Inc. Our automotive diagnostic tools can read and log any obd check engine code data.
aldlcable.com aldlcable.com

there are 4 little pins on top of the USB end, but as per the provided instructions they are covered in the "normal" configuration...

I'll try a different port, thought that when installed a certain COM port was assigned to the hardware. Not the most computer savvy one here, still use a flip phone and running windows 7 on a laptop that is at least 10 years old 😆
 
DieselAmateur said:
I'll try a different port, thought that when installed a certain COM port was assigned to the hardware. Not the most computer savvy one here, still use a flip phone and running windows 7 on a laptop that is at least 10 years old 😆
Click to expand...

This.

As an aside: COM (Communication) ports are a real legacy and obsolete PIA from the 1980's. There is only one laptop OEM that offers a COM port as a special order today. You have to keep in mind that they share interrupts (IRQ#) for example COM1 can share the same interrupt number as COM3. Depends on how it's configured in the computer BIOS, card, etc. If COM1 shares an interrupt with COM3: NOTHING HAPPENS when COM3 requests an interrupt until COM1 does something with the interrupt because it has the CPU's attention. Thus if COM1 does nothing and COM3 also does nothing. Ever watch a COM3 MODEM lockup till you moved the COM1 mouse and then you get sudden text on the screen from the modem? Yeah I am archaic. Emulated COM ports via USB is just a Goat, Bailing Wire, and Duct Tape, with just enough lube...

What you want to do is look in the device manager. (Click Start, Right click on Computer, and select Manage.)
How many COM ports do you have?
Then check each one for the IRQ#. (Expand by clicking on arrow by ports, right click and select resources tab.)
Make sure the USB adapter, in your case COM3, isn't sharing a IRQ with another COM port.

If the USB cable is unplugged the COM port may not appear in the device manager. If you move it the new COM port should show up. You may have to select Action then scan for hardware changes to see any change. Unplugging the cable may show you what COM port to use as it goes "POOF!".

I suspect you may need to be using another COM port like COM5. You may have just grabbed COM3 that is being used for something else like the iAMT in the pic below.

The # 17 is the IRQ number we are concerned about in the pic below.

com_irq.jpg
 
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What OS does the computer have?

IIRC, it only works on computer up to Windows XP.
It does require the computer to download some driver from the cyber world.
In my case, it was done automatically but that was way when XP was still supported by MS.

I suspect, you can probably make it to work with Win 7 but not sure on Win 10.
 
@JMJNet Assumed Windows 7 from Post #8 and to clarify: Windows7 OS used for the above device manager pic.
 
Thank you for the details, @WarWagon . I'll attempt to determine what the whole COM port situation is.

And yes, running Windows 7 on and old Lenovo R61 laptop. Just like these old trucks, sometimes it's just easier to stick with the stuff you already are familiar with...
 
My adapter came with the software, there is a toggle switch on it.

My computer is 13 years old :), running Windows 7 with no problems.
 
I too have been having the no connect issue. The free version would work for me 50/50,, Then after swapping IP, I needed the relearn,, so I pony'd up and paid for full version. It has Never connected for me since. I even reformatted my, yes 10yr old lappy with Win 7 pro, and Only new version. of GMTDscan. Still no connect. I'll be looking into this fix as well.
But I was fortunate to have a go worker, get a Tech1 from a tech friend of his. So now I have that, I'm working on a persistent code 19.
 
As I said, it takes some work for Win 7 to work since a lot of the driver are coming from Win XP.
Most XP driver can be used in Win 7 environment when XP was supported.

I suspect, if the software is in Win 7 computer since Win XP was supported, the driver is readily available.
But, now, it takes some work to get it to work since Win XP is not supported anymore.
We have to find the driver manually and install it manually.

Mine is still running on Win XP computer so I am not sure where to find the driver anymore.
May want to check with Swedeburb to see if he still have the driver or knows where to get it.

That is my suspicious, after working with computer for over 20 years. I can be wrong.
 
The OBD-1 cable came with a CD that was supposed to have the driver. Might be another week before I have time to monkey around with the COM and port settings as @WarWagon suggested.

I've emailed ENGH Motors where the software came from and have yet to hear back.

Given the PITA of the software and it seemingly not being supported by newer operating systems, it seems the better route would be to find a used tech1 on ebay, more money up front but less time wasted overall chasing down bugs like this...
 
I was able to get a Tech-1 from a friend of a tech I know. Hooks up know problem, and boy have a I learned a few things about my rig.
I was able to do the ABS purge function a few times, after I vacuumed out the Master, and refilled. I replaced my IP with a supposed good one, but got codes right away with it, but it wasn't' timed properly either,, just lined back up the way the old one was.
So, having just done Timing chain, H2O pump, lower upper hoses, Balancer, and Pulley, I searched out the tech one, not being able to get my GMTD working, to see where I was at timing wise.
I lost count of how many times it took me to move the IP, then do learn,, then move Ip,, then learn,, Then move back the other direction,, Then still to find, if you do learn again with out moving the IP, you'll land on a different timing. I had -1.84 and thought, well good, that's close enough. But still getting SES light, code 36 Injection pulse long. Not sure, but it seems like just a slice of a hair can be a bigger adjustment then you think, and 1 of the specs can be good, but another one off. The desired and Measured Injection timing, was off, but tdc was 1.84,, got code. So after a few more tweaks and relearns.
Tonight I think I got it licked with these numbers, and no code, yet.
TDC Offset -1.94
Inj Pulse width 2.05~2.19
Inj Time desired and measured 8.8~8.9
Fuel rate 9mm~10mm All while idling @ 656 RPM
While it's relearning the Timing offset, the screen shows, desired 0.0 and measured 2.3~2.7
 
Still have not heard from ENGH Motors. Given zero customer service, would not recommend.

Was finally able to get the engine timed by a mechanic neighbor, and I must say the difference is night and day. Much better throttle and turbo response, I've gained about 5 psi in boost and EGTs are ~500 degrees cooler.

I'm still hoping to get the software to work, as it is nice to be able to communicate with the truck and see the internal workings in real time.

I keep having issues with the software not being registered too. On ENGH motors website it says to run the program as an administrator. No matter how many times I do this, the preference isn't saved and I have to re-register it every time I open it. Not sure if it's an issue with my OS, computer, software or any combination. Going to take the laptop to the place where I purchased it and see if the computer wiz can figure out the "run as administrator" issue.

Will report back when expert help is attained. Thanks for chiming in everyone
 
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