CA93accord

Normal operation by turning the key to the ON position, the CHECK ENGINE and D4 lights on the dash should light up and turn OFF after 2 seconds. This indicates the fuel is primed for engine start.

My 93 Accord LX: CHECK ENGINE turn ON and turns OFF but no D4 light. In addition, D4 doesn’t light up while in D4 position. BUT............. on a hot day 5 minutes into a drive, the D4 turns on. on a somewhat warm day, no D4 light. hot days seems to trigger the light to turn on intermittently turn-on on a consistent basis.

There are no codes. It shifts thru all gears and over drive great. It is probably the original engine and transmission. I have about 209K miles. I regularly change engine and transmission oil on regular intervals.

I have removed the center console to see if there was a loose wire; nothing. I jiggled the individual wires on the gear position switch in hopes of the D4 light turning ON while in D4 position; nothing. I wiped down the connections in the gear position switch in hopes of the light turning ON; nothing.

I need help. Do I need a new switch? New dash gear position indicator bulb? New TCU?

MAD_MIKE

Back probe the gear selector switch and verify there is continuity of power.
If there is, it may be an issue with the lamp or cluster circuit board.
Try swapping any of the other gear lamps (D3-1) to see if the problem follows the lamp, if so you just need a new lamp. But you need D4 lamp functional to retrieve any AT codes.

CA93accord

Mad mike,
thx for quick reply. I will check for continuity of all wires on the wire harnesses. I was planning to switch the bulb from d4 to d1 but being somewhat ocd, i would rather orser a new one.

Do u know where i can pick one up? Also, do you think i need to repair capacitors in the tcu? By repairing capacitors, will it light up my d4 light? For the latter question, it will save me from removing gauge cluster

Alaina98civic

Could be a shift solenoid Has damaged wires. Had my minivan worked on, they got brake fluid on one of the wires and it ate the plastic off leaving the wires exposed. Trans shifted fine but D lights flashed.

ctrgod

Did you check the light itself? The actual one in the cluster, it's more than likely not sitting in all the way and only making contact randomly...

CA93accord

i haven't done of the suggestions yet. I just had surgery and I am on bed rest. next week I will trying:
1. checking resistance and continuity of the gear position switch on center console
2. checking shift solenoid if wires are torn or something
3. checking gauge cluster. before 1 and 2 suggestions came to me, I was going to do the gauge cluster. I rather do the easier one which are steps 1 and 2.


as soon get to it, I will post the end result.

MAD_MIKE

Damage to underhood wiring will not affect selector lamp operation. 90-97 Accords gear selector switch is located on the gear shifter.

Mini-lamps for the gauges are as follows.
78181-SM4-901 SOCKET ASSY., BULB (8V-150MA) (BASE:WHITE)
78182-SM4-003 SOCKET ASSY., BULB (14V-100MA)(BASE:BROWN)
78183-SM4-003 SOCKET ASSY., BULB (14V-100MA)(BASE:BROWN)
78184-SM4-003 SOCKET ASSY., BULB (14V-60MA) (BASE:GRAY)

Look at the base color, can be purchased from the dealer for $2-4, some folks have had luck finding the mini-lamps(baseless) at Radio Shack. Match voltage to mA rating before purchasing.

CA93accord

Mad mike
where did u find those numbers? Ive been searching mostly everywhere. Thank you sooo much. I will take those and search for a site to purchase prior to pulling cluster to minimize down time.

By chance do u think tcu has a play on d4 not lighting up?

MAD_MIKE

METER COMPONENTS (NIPPON SEIKI)

MAD_MIKE

If the TCU was acting up with D4 on and off you would probably feel some strange or unusually shifting.
If the transmission upshifts normally and at 50MPH you feel the lockup function then I highly doubt the TCU is acting up.

D4, S, SRS, ABS, CEL, etc warning lamps may fail just like any other lamp/bulb. If the filament is broken but makes intermittent contact it can relight until the break opens up again.

CA93accord

mad mike,
thanks again for your expertise. I will then first tackle the light bulb in the cluster.


btw, I will probably order 78181-SM4-901 SOCKET ASSY., BULB (8V-150MA) (BASE:WHITE) since it requires 7 bulbs which......i think would be the 7 gear positions (P,R,N,D4,D3,2,1) It makes since to me. lol.

MAD_MIKE

I would agree, but verify before ordering.
Also, if you can, do not remove/loosen the lugs/nuts that hold the gauges to the circuit board. Fuel gauge has a tiny strand that can easily snap off and cause a permanent FULL reading on the meter when removing the rear nuts. Try to just remove the front plexi and black board off the face of the cluster, and not disassemble the gauge cluster.

CA93accord

mad mike
I swapped the D4 and 1; still no light on D4 and now no light on 1. I even swapped out the P and D4, (thinking that it was a bad bulb); D4 no light but P has a light.


I am stumped

CA93accord

I am going to test continuity on the gear selector switch to see if there is good continuity.

CA93accord

mad mike,
gear selector checked good for continuity. I was going to just stop and order and wait for bulbs, so I temp installed the gauge cluster in the hole. as i pushing the cluster in the hole, D4 light came on. i found out there was a loose wire, either in forward wire bundle (the one that plugs on top of the cluster) or the lower right wire bundle.


more to come

CA93accord

Aaaaha
the trouble was the wire harness forward of the cluster...the one that plugs from the top ....was loose. I figured it out when i was in gear (d4), trying to jam it back into the cluster hole. It would come on and turn as i was positioning it. I am glad it wasnt the tranny or any other problem.

MAD_MIKE

In Ford-speak that is called the wiggle test.
Basically go around and try and find a bad connection by wiggling suspected components. Kinda annoying at how simple it works.

Great that you found the problem!

CA93accord

I was wrong about which wire harness causing my D4 light to come one by looking at the wiring schematics. it was the wire harness that is connected to the light dimmer (tensiometer). the one on the right. more to come from the wiggle test. I might have to have someone re-solder some more.


thanks for checking on a fellow Honda motorhead.....well mediocre motorhead. lol