Strange one.

[bgcntry72]

Pulled an ECU from a '98 in a yard to keep as a backup to my '99. When I install it, all is well, and the engine seems to run better than with the '99 computer it came with. The only exception is that with the '98 ecu, I have no cruise control. The light will not come on, nor will it activate. If I swap the '99 box back in, the cruise works fine. Any ideas? Both trucks had no ABS, AW4, 231, etc, if that matters. TIA

[Rev Den]

Did they both have cruise?

Rev

[Eagle]

That would be my guess as well -- maybe the donor vehicle wasn't equipped with cruise, so its computer wasn't programmed to recognize it. The OBD-II computers are flash programmable -- maybe it could be flashed to activate cruise control, but a dealer would probbly charge more to do that (although it requires about 30 seconds) than you paid for the unit.

[bgcntry72]

My 1999 did not have cruise control when I drove it off the lot. The dealer installed it later. When I asked him today, he told me that nothing had to be done to the computer when the cruise control was installed. I don't know if the donor vehicle had it or not.

[rixXJphx]

Try the architect's initial approach to all things electronic:
Plug in the 'new' unit, disconnect the battery then reconnect.

-Rick

PS: I can do most anything you want with concrete, masonry, steel, wood and glass; but I'm stupid when it comes to electronics. :rolleyes:

[bgcntry72]

Removed MSD Blaster coil and went back to Ecoil after finding a plug at a boneyard. Problem solved. According to my codes, I was getting a faulty voltage reading from the aftermarket coil, as well as misfires. Stock is good.

[bgcntry72]

the above response belongs on another thread of mine. ECU disparity still exists. Thanks.
:anon: