Please check my work so far...

Driving home yesterday my Accord started saying "Stop driving me!"
- CEL came on steady
- D4 trans light flashing green
- Low idle at 500rpm (in park or neutral) but never died.
- All other lights and gauges read ok
... I made it back home.

When I short the Blue 2-pin Diag port behind the glove-box, D4 flashes the code 1-4. According to this page:
https://www.hondaaccordforum.com/for...s-codes-33940/
it appears to be:
TCU Codes: 14-Linear (line pressure control) solenoid open or shorted.

Questions:
1. Am I on the right track so far?
2. If so, is it saying the transmission fluid pressure may or may-not be ok, but regardless ... it actually sees a fault in the solenoid?
3. I wonder why CEL didn't flash out a code for me?

I did replace the radiator (which includes the built-in transmission fluid cooler) a few months ago. But everything appears to be fine with that repair. I've driven the car pretty hard since then, and this new problem just started. Transmission fluid level is good.

 

Make sure battery and connections are good.

Reset the ECU by pulling BackUp fuse in underhood fuse box for 20 secs. See what codes return.

TCU code 14 is an electrical problem, short/open in FAS Brn/Wht wire between the D3 terminal (TCU) and ECM, Faulty barometric pressure sensor (on ECU not repairable), or faulty ECM.

Most likely an ECM fault, but it is possible to sort out the fault w/ the diagnostic flow chart in shop manual. See Online Manuals post in DIY forum for 94-97 Accord emanual download links.

Nothing about hydraulic pressure fault.

good luck

 

Thanks for the quick reply. This forum is excellent. Just knowing I'm on the right track now is invaluable.

RE: no actual hydraulic pressure problem
- That's great news ... thanks.

I got brave enough to drive around the block. No CEL or flashing D4. Idle (after warm-up) was fine. Stored TCU code is still there. I'll try the reset and other things you mentioned.

 

Ok, I serviced the battery terminals and charged battery (all looked good but did it anyway). I also checked the green connectors on the 2 valve/soleniod sets for corrosion inside but they looked ok (they are right on top begging to be checked).

Pulled the fuse and reset computers. Drove car on 10 mile trip to store and up to 70mph. About 90f outside. All ok.

But today (about 100f outside), about 15 miles into trip CEL and D4 flashing again. Feels like car is going into "limp" mode or something. Same code and symptoms as above. Engine is not over-heating, and nothing is leaking. I can smell ATF fluid like transmission is very hot.

Not sure how me or car check over over-heating trans. Fluid level still good (fluid is not new but doesn't smell burnt and still is redish brown color).

I got the real Service Manual (very cool ... kinda sad I'm just now getting this). Looking at Code 14 Flow-Chart. I guess I will pull the computers and take a look and them and the wires. Too bad Code 14 troubleshooting doesn't include some sensors/vales or something inexpensive.

 

It looks like the code 14 from the D4 light would indicate a bad ECU.

Go car-part.com. This site searches junkyards that subscribe to it. Search for used engine computers. You can sort by distance or price to see what is available locally.

 

Let me be sure I'm reading this right.

Driving: CEL on steady and D4 Flashing
SCC Diag Code: TCM-14 but CEL is on steady (no code)

Flowchart for D4-Code14
Is MIL (CEL) on, YES (it is) ... go to PGM-FI section 11
(you don't get to complete or really even start flowchart)
Bottom of Page 11-16 says:
On shorting SCC, if MIL stays on steady, the back-up system is in operation. Replace ECM (and see if indication goes away).

Please verify I'm reading that right.

And back to the original TCM error ...
14-Linear (line pressure control) solenoid open or shorted
... there is not actually a part called "Linear (Line Pressure Control) Solenoid" is there?

BTW, thanks for the help guys. Us Texans gotta keep our Hondas going.

 

My ECM, TCU, (and ABS) computers

 

BUT, then it says (in a couple of places later in the chapter)

If the SCS Short Connector is connected and there are no DTCs stored in the ECM, the MIL will stay on.

I don't understand ... which is it?

 

The two statements do not appear to be mutually exclusive. Also when japanese is translated to english, sometimes things get slightly garbled. Too close a read can make your head spin.

A used ECM is < $50 on ebay and car-part.com. I suggest trying to swap the ECM for a used unit to see if that resolves the problem.

good luck

 

I just want to make sure that a steady-on CEL/MIL Light (with the shorted SCC) is telling me "Check PGM-FI" and not "PGM-FI is fine ... continue troubleshooting flowchart" (which is the opposite meaning).

I see what you're saying though ... one of the confusing statements is RIGHT AFTER the computer reset procedure. Sorry, should have read that closer but it was late (trying to work at night when it is cooler).

Would you say the following statement is true?

Immediately after a computer reset (but before a drive cycle) if you short the SCC ... don't interpret a Steady-on CEL/MIL as an error. It might just be telling you there is no current DTC (no error or problem).