mweaver

I have a 1992 Honda Accord LX that shifts normally and drives fine but the D4 light starts blinking after going about 1/4 mile or so. I do not lose any power and it shifts just fine into the other gears.

Any ideas what could be causing this? I have replaced the TCU, thinking it might be failing but that didn't fix the problem.

I want to catch this before it turns into a bigger issue.

Thanks.

Mike

projectTeG

try your main relay

patastinky

the solidnoids on your tranny are most likely clogged up or need to be repalced

mweaver

patastinky:
I noticed a lot of sludge on the drain plug when I took it out to replace the tran fluid. I just had the tranny flushed by super lube and this is when the D4 started blinking. I only drained and replaced the fluid again because I couldn't be sure if they had put the correct fluid in.

projectTeG:
I was just reading up on the possibility of the main relay causing this problem too. I think it is the cheaper fix to try before going after the solenoids, whihch cost an obscene amount of money per item.

Thanks for the quick replies!

P_Adams

Is there an associated CEL present?
Was the TCM a new unit or an EBay/used unit?
Have you tried to pull a code from it?

I question the shift solenoid theory in that you state it's shifting properly.
I've seen the VSS do this, although it usually effects the ECM as well.

P

P_Adams

The "solenoids" that have been bantered about in this thread can be serviced and tested.
The gaskets which seal them to the case incorporate filter screens which are ment to catch debris. It is possible that the flush you had performed dislodged some gunk loose (although unlikely).
It may be worth your time to pull the solenoids, clean the screens and check the solenoids for either a short or open circuit before reassembly.
Since you relate it's shifting properly, I question it will help, but it's well worth the effort if it does

P

mweaver

There isn't a check engine light on, at all. Just the D4 blinking.

I bought the TCM from a dealer in Miami, Fl. It is a Re-manufactured unit that they programmed for my vehicle.

I was going to try to see if I could get a code but have not been able to locate the System Diagnostic Connector. I looked where others have said it was to be but no luck.

I will try the cleaning of the solenoids tomorrow after work.

mclovinF22

use the paperclip method which is used for checking your cel.... look up my thread on 90-93 accord/obd1 cel codes..... it instructs on how to pull the codes.... the D4 light will flash the same way and throw you codes and the same rules apply...

long flash=10
short flash=1

I.E:
long, long, short= 21
there will be a brief pause between the codes and when all the codes have been shown it will start over again from the beginning but pay close attention to the flash patterns because they can get confusing.....

TCU Codes:

CODE LIST:

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.

mweaver

ok. I finally found the diagnostic connector. It was hiding in plain sight of course.

I got a code of 9 - Counter shaft or transmission speed pulse generator open or shorted (but from another listing of codes it days it is the NC speed sensor). I am guessing these are one and the same.

I am now looking up how to go about checking the sensors.

mweaver

Well. I have a feeling it is definitely the VSS. This morning when I went to take it to work, it wouldn't shift out of safety mode. Then when I went to put it in Park, the D4 light stayed on solid.

How hard is it to replace this sensor?

I have looked all over for a good picture of where it is at on the trans but cannot find one. All I see are line drawings, which to me aren't very helpful or pictures of later model vehicles, when doing a google image search.

Thanks.