CODE 628 EXCESSIVE CONVERTER SLIPPAGE ON MY 95 GT MUSTANG CONV-

MUSTANGMAN95 · Sep 19, 2023

HI: I AM FAIRLY NEW TO THIS FORUM AND WOULD LIKE TO KNOW IF ANY OTHER POSSIBLE FIXES OR CHECKS OTHER THAN REPLACING THE TORQUE CONVERTER?
THE CAR RUNS AND SHIFTS WITHOUT ANY NOTICEABLE SLIPPAGE, SO I CAN'T UNDERSTAND WHY I HAVE THAT CODE! THANX UP FRONT IF ANYONE CAN HELP!
MUSTANGMAN

Wmac · Sep 21, 2023

What scan tool are you using to read that code?
Tried resetting the ECU?

MUSTANGMAN95 · Sep 21, 2023

OBD-1 IS THE ONLY ONE THAT WORKS FOR 95. WHAT IS AN ECU?

Wmac · Sep 21, 2023

ECU is the computer. Disconnect the battery cables for 30 minutes, then reconnect. The computer will then relearn its strategies.

What scan tool did you use to obtain that code?

Have you had the trans serviced in any way lately?

You can do a self test of the converter by driving at a steady highway speed, then tap the brake pedal lightly with your left foot.
You should notice a slight increase in rpm on the tach.

MUSTANGMAN95 · Sep 21, 2023

THANX, I'LL TRY THAT, BUT I WAS JUST OUT IN THE CAR AND WHAT I DON'T UNDERSTAND IS THE TRANNY SHIFTS QUICK AND CORRECTLY AT ANY SPEED! I CAN TAKE OFF FROM STOP AND STEP A LITTLE FAST AND TRANNY WILL SHIFT (IN OVERDRIVE) AND NEVER MISS A BEAT! I HAVE NO SIGNS OF ANY TORQUE CONV SLIPPING, IT'S SOLID!
SO I CAN'T FIGURE OUT WHY IT HAS THAT CODE??

Wmac · Sep 21, 2023

So the trans has been modified or the ecu is chipped? AODE's don't shift "quick" in stock form.

Suggest you turn off caps lock.

MUSTANGMAN95 · Sep 21, 2023

It could have been modified, the car has headers, mild cam and 4:10 gears, so maybe it was! I only drive in OD , tried without od , but it really shifts fast! I was considering to put 3:75's or so ,but only use it mostly within a hundred miles or so! gets about 20 mpg in od! I haven't found out if it is original tranny or not or even original motor, but runs great, so I don't care! don't know what ECU is?
Thanx for info, I really appreciate it