CRC-1000 Dakota Digital DBW Cruise and a GMPP LT4

[stan65]

blitzer454,

Thanks for the last response. Been a while since I looked back at this thread.


I bought a second MPVI2 and added a parallel OBDII connector. Although this was not a cheap solution, it has worked flawlessly.

When you mention "add a pull-up resistor to the battery on the I/O cell" are you saying add the pullup resistor to the input point on the CRC-1000?

You have resistance in mind? I am willing to try to do this without the dongle.


Also in my first post, I miss typed and said not..... the "not" shouldn't be there

If I start the car with the dongle and go for a drive, the cruise will not engage. and function perfectly. The light on the CRC-1000 goes green when powered on and when engaged turns amber and stays amber until I hit the brake or clutch at which time it goes back to green. If I unplug the dongle while driving, it will immediately shut the cruise off.

[blitzer454]

Originally Posted by stan65

blitzer454,

When you mention "add a pull-up resistor to the battery on the I/O cell" are you saying add the pullup resistor to the input point on the CRC-1000?

You have resistance in mind?

Yes, add a pullup to battery voltage on the clutch or brake input to the CRC-1000. A 10k resistor will work. I would start with the clutch since it's more likely to be the problem.

[randy]

Where are you pulling your speed signal? I had to use the signal from the transmission harness connector on the gmpp ecu. Speed signal wasn’t accurate since we didn’t use the 40 tooth transmission. We flashed the ecu with a tire and reluctor conversion to trick the ecu speed and now everything is perfect

[stan65]

Final conclusions.....

After extensive testing, my conclusion is the GMPP ECU does not transmit the data on the bus unless its polled. Without the TCM in a manual transmission application there is nothing to poll the ECU. When the HPTuners dongle is attached to the ALDL connector, it is polling for data and therefore the Cruise control works.


The solution I opted for is to add a second ALDL connector to the bus and attach a used cheap HPTuners dongle to the extra port. (Yes I can have 2 Hptuners dongles attached to the car at the same time to continue to tune)

I didn't want to leave my "good" dongle in the car.

Thanks,
Stan