DASH CLOCK DISPLAY MALFUNCTION

Dornoriginal

Salutations!

Background: 1995 Avalon with 202,404 kilometers
OBD TERMINAL is classified as Type I - local component dealers are unable to perform scans.
Prolonged history of "check engine light" activation...
Implementing the "thirty-minute battery disconnect protocol" resulted in the light being out for weeks or months.
No change in engine or any other system performance; no variation in mileage or behavior.

Present Concern(s)
The leftmost digit of the Dash clock consistently displays both "0" and "1" at periods over 9:59 throughout the 24-hour period. For instance, ten minutes past twelve (AM or PM) is represented in four numbers... One with zero overlaid equals one. two.... 0/1 0:12

The luminosity of the leftmost digit fluctuates from dim to brilliant, according to adjustments of the instrument panel's brightness.

Assumptions: The ECM regulates engine operations and the dashboard clock, using the ECM timestamp for fault codes.

ECM induces clock behavior

Options Being Evaluated...
Refrain from any actions regarding the clock; disregard it entirely.
Deactivate clock - sever connection at clock/cable interface

Proceed with the "thirty-minute battery disconnect protocol" and disregard continuation without hardware replacement.

Replace the ECM with a reconditioned one, assuming the new ECU would return the clock to normal functionality.If the clock problem persists, accept it.

All comments and hypotheses are welcome!

Martin4car

Your vehicle likely has OBD I diagnostics. A tiny box should be located on the driver's side of your engine compartment, next to the fuse and relay box.
To get diagnostic codes, connect a jumper wire between E1 and T1 in the engine compartment's diagnostic connection, then count the flashes of the Check Engine Light.
Assistance may be provided using the codes you will get.
I question the clock's significance to the ECM.

Dornoriginal

Thank you. I am familiar with the "jumper – count the blips" decoding method; your remark served as a helpful reminder.

I am particularly interested in any correlation between the clock's functionality and the ECU.

hockeyman

I had a similar issue with the clock on my 1995 Avalon XL; the problem of a faint display persisted for around two weeks before resolving itself. That occurred around three years ago. No issues have arisen since then. Still unable to ascertain what transpired.

Martin4car

Replacing the clock would be simpler than replacing the ECU, unless there is a code directly associated with the ECU.
I highly suspect that the clock is not linked to the ECU in any manner. Only a wiring diagram could verify its status.

TURTLEMAN

The 1995 Avalon complies with OBD2 standards. It exhibited compliance early, similar to the Camrys outfitted with the 1MZ-FE beginning in 1994. Locate the OBD port behind the little door situated below and to the left of the steering wheel. It is positioned above the fuses, necessitating a crouched posture to see it.

I have not encountered the concept of the ECU reading the clock.

hockeyman

The clock is directly linked to +12 VDC by a 5-amp panel fuse.

Dornoriginal

Thank you for reiterating previous replies and providing further insight and depth.

Dornoriginal

😃