95 Honda Accord
4 cyl vtec auto trans
180k mi
Symptom:
After 15-20 min driving:
Check engine light comes on solid – no flash
D4 light comes on flashing
Code check: one (1) long four (4) short
Believe this is TCM related, but no specifics
Car taken to Honda Dealer
Trans pressure/mechanical check indicates there is no mechanical problem
Changed TCM with known good, problem reoccurred during the test drive.
Will pick-up the vehicle unrepaired.
Any suggestions would be welcome.
Thanks in advance.

1995 Honda Accord
4 cyl vtec auto trans

 

Code 14 - I believe you have a shorted out ignition signal circuit.

Here is what the code says:

Idle Air Control valve circuit / ECU Open or shorted out ignition signal
circuit / No signal to ECU

 

Was the code supplied by Check Engine Light (ECU code) or D4 light (TCU code). Both have a code 14.

In either case, you should get codes for both ECU and TCU and post them.

ECU code 14 is Idle Air Control Valve circuit electrical fault (short or
open).

TCU code 14 is Short/Open in FAS (Brn/Wht) wire between TCU terminal D16 and ECU, or Faulty ECU.

good luck

 

Thanks for the response:
CEL was on solid, D4 blinking. The TCM provided the the code 14. CEL never blinked during the trouble code check. Honda dealer confirmed the code 14 from the TCM.

An additional as of this morning: drove about 50 miles to work this morning, with the A/C off, no problems or indicator light. Will, on the way home try with the A/C on and see if the trouble returns. Will advise.

 

I don't see the significance of AC on/off.

Most likely, this intermittent fault will return. If it returns, I would suspect a faulty ECU. Used units are cheap.

good luck

 

I agree with TexasHonda. Likely ECU problem if this happens again.

 

Agreed, A/C just coincidental. Still looking. Will pull the TCM the is weekend and check component condition. Understand leaky cap and /or burnt resistors may cause the problem. Don't know much about the FAS system, but will pull the book and see what it says. Will advise. Tx.

 

Also, looking locally for a used ecu and tcu...tx again

 

Trying not to make a novel out of this:
Problem back. Notable items.
Ambient temp much hotter, car in P/L probably > 100F today, the other day, much cooler.
Returning home: MIL on continuous, D4 flashing (check code, still 14).
Car died while trying to idle.
Turned the key (without first turning it off), engine turned over, but would not start.
Turned the key off, the car started up immediately, no hesitation. MIL/D4 came back on after a short period.
Symptoms still ECU likely?
Also, someone mentioned FAS…how about a hint. I see it mentioned in the wiring diagram between the TCU and the ECU, but have not located a reference to read.

 

Check Online Manuals post in DIY forum for links to a 94-97 Accord manual you can download. This has wiring diagram you need and locations of wiring harness, connectors, etc.

good luck