liquidh8

Hey all. In another post I said I picked up an 81 buick wagon (g-body) with an 86 Grand National drivetrain. The car runs like poop. It has an aftermarket chip, seems to be running super rich. I took my snap-on MT2500 scanner and hooked it up to the aldl, nothing. No data stream or anything. The SES isn't hooked up in the dash, so I took a test light and hook it up to the SES wire in the ALDL port. The light flases the 12 code, I have a MAF code, (been rplaced yesterday and still have it), and a code 51, EPROM code. So I think it now is in limp home mode. Is there a way to check the ALDL to see if it is putting out data? Can I tap into the wiring right at the ECM to make sure the wire isn't jacked? Or is my ECM just stoved.

On a side note. I managed to get an xdf, a few stock bins, and an ADS file for tunerpro for it. And I just order the G@ adapter with the .45 leg spacing so i can burn a stock chip for it.

RBob

iTrader: (1)

Funny you mention t-V6, it is rare to have anyone with a '89 TTA come visit here at diy_prom. Anyway, that ECM uses the SAS (slow-as-s) ALDL at 160 baud. Should be sending data all of the time. Pin E on the ALDL, pin A8 at the ECM.

A DVM should show other then straight 0 or straight 5 volts on the ALDL line.

Also note that the '148 was used in other Buicks. So it isn't all that special (no need to pay a premium for it).

RBob.

liquidh8

So it should have a voltage in between, or is it variable? Constantly changing voltage?

I had a 87 lesabre t-type a few years back and it had a 148 ECM, I had a spare and sold it to a guy with a GN. Go figure I get something that can use it as a spare. lol.

Well, when I get a chance today or tomorrow I'll put a DVOM on it and check it out. So if I am not getting any data, it'll be safe to assume the ECM is toast then.

Thanks RBob.

RBob

iTrader: (1)

Just looked at a '7747 ALDL output with a DVM. Which has the same SAS ALDL.

With the meter trying to auto range it just flipped between the two ranges without being able to display a voltage. Set the range to display 5 volts, it flipped between about 3.5 and 4.something volts.

The ALDL stream is digital 0 - 5 volts. And is SAS, which is why the auto-ranging couldn't lock in.

You should also look for the SES blink at key-on. It also may be that the PROM is bad.

RBob.

liquidh8

Cool, I'll have to look for the SES blink. I'll be hooking up a test light again for the SES, so when I turn on the key there is a steady blinking right? Man, I forget. My EBL I never hooked up the SES since I have the craptop on it so much.

O, I vaguely remember seeing a lockers board being used on the '148 ecm. A diy version. Any thoughts on this?

RBob

iTrader: (1)

Key-on, engine-off, SES on, blink off, then on solid.

O, I vaguely remember seeing a lockers board being used on the '148 ecm. A diy version. Any thoughts on this?

I've seen that too.

RBob.