Not sure if I'm reading the codes wrong but I get code 7 from my CEL and codes 41 and 5 from my D4 light. Comparing to the check engine light codes in the sticky I cannot find what they are. Read that code 7 is TPS. Not sure about my transmission codes however. My AT has been slipping downshifting from 2-1.

CEL blinks 7 long. D4 blinks 4 long and 1 short, then blinks 5 short.

 

What car is this? Hmm maybe you got it backwards? Coz D4 codes only go upto 15 and the CEL is the one that goes up to 90 something.
https://honda-tech.com/forums/honda-accord-1990-2002-2/90-93-accord-obd1-cel-codes-2630683/
Check that site out.

 

ECU Code 7 is TPS, a faulty TPS would keep the transmission from upshifting or cause erratic shifting.

TCU only has 15 codes. Are you sure its not Code 4 and 15?
TCU code 4 is VSS(vehicle speed sensor)
TCU code 15 is 'shorted kick down switch, which makes more sense with the downshifting issue.

Code 41 is non existant, and code 5 is console switch.


TCU Codes:


1-Lock-up solenoid 'A' circuit open or shorted.
2-Lock-up solenoid 'B' circuit open or shorted.
3-Throttle Position Sensor circuit open or shorted.
4-Vehicle Speed Sensor open or shorted - No signal from speedometer.
5-Shift Lever Position Switch circuit shorted.
6-Shift Lever Position Switch circuit open.
7-Shift Solenoid 'A' circuit open or shorted.
8-Shift Solenoid 'B' circuit open or shorted.
9-Counter shaft or transmission speed pulse generator open or shorted.
10-Coolant Temperature Sensor open or shorted.
11-Engine RPM (Ignition coil signal) open or shorted.
12-(No code 12 used)
13-Main shaft speed pulse generator open or shorted.
14-Linear (line pressure control) solenoid open or shorted.
15-Kick down switch circuit shorted.

 

Yes I do believe its now code 4 and code 15. The car has been jerking when downshifting from 2-1 like the clutch is not engaging. The other day the clutch slipped completely and didnt engage at all. Now I'm not even sure why the TPS and VSS would be my issue here. Seems like my tranny is about to go.