Tunerpro RT $4F connection problems

[1project2many]

ALDL Mode... had to dig out the old books on that one since it's been so many years since I had to play with it.

"ALDL (10K or Special) Mode (not used on all engines)
In this mode, all information incorporated into a specific engine and ecm is obtainable. However, in this mode the system operating characteristics are modified as follows.
... Closed loop timers are bypassed
... EST (spark) is advanced
... IAC will will control engine idle to 1000 RPM +/- 50 rpm
... On some engines canister purge will be enabled
... P/N restrict functions will be disabled"

As I remember it, we used ALDL mode in carbureted applications. You would do neat tricks back in the day like speed warmup along or search for vacuum leaks or force closed loop right away to start adjusting the computerized carburetor's rich and lean stop. Or you would crank the engine rpm up to 2500 so the exhaust manifolds would get red hot and burn the carbon off the O2 sensor and the plug tips. Remember that in those days we still diagnosed much of the car with a voltmeter and common sense. ALDL data on a CCC car was extremely slow and in road test mode it was sometimes limited or not available.

Also, for a while you could force ALDL mode and get through sniffer emissions tests. Eventually the states caught on and would flag you if idle was too high. So you'd run it in ALDL mode at 2500 to get the cat and exhaust super hot then pull the connector and run the sniffer test right away.

You can also put a 3.9K resistor across A and B to force the ecm to run in backup fuel if you're so inclined.

Why the OP needs the 10k resistor is a mystery. I'd suspect the logger software/hardware combo, not the ecm, is at fault.