primemal

my 93 accord has a flashing d 4 light ive tried 3 tcu and still flashing,but now it doesnt start up sometimes.The first 2 tcu i bought from the junkyard 1st one worked for like 2 weeks then flashing d light came on and for the firts time car wouldnt start,2nd tcu dint fix problem.and now the 3rd one is a rebuilt one and the d4 light is still flashing.Can any one help me?

shrewz92

It may NOT be the TCU. It's very important to find the service port to jump the plug. On your passenger's side, the port is a female, two-prong, blue-plastic tipped wire. Slip a small-guage jumper wire (paperclip for instance), then turn ignition to 'ON' but don't start the car, just get juice to all the circuits. When the plug's jumped, the d4 should flash a combination of long OR long&short flashes. The Check Engine Light (CEL as most folks here refer to it) may also flash. A 'long' flash (maybe 2 seconds long) indicates a 'single' digit code. A 'long' flash, followed by 'short' flashes = a two digit code. The TCU and ECU may have several of those stored, so there'll be a pause of 5 or so seconds between any stored codes. Be patient, count them all, until you notice them repeating. Write down the codes. I KNOW that on this forum, there're many postings for TCU & ECU codes/what they mean. Search those out. Since the Speedo is working intermittently, it may be the Variable Speed Sensor causing the intermittent flashing of d4, but GET the codes. That's your first step. You can do an easy, quick check to see if your junkyard TCUs are (at least visually) servicable. Unscrew the 4 screws on the outer-casing and look at the circuit board. DON'T TAKE THE BOARD OUT for personal satisfaction. Point the TCU plug-ins towards yourself and look in the lower right corner, closest to the connectors built into the board. Many TCUs exhibit a black, smoky-colored area where the resistors & capacitors leak, then short out. If you see that, you probably have a NO GOOD TCU, but they CAN be rebuilt, if you're handy with a soldering iron. Word of advice from Someone Who's Been There: BE CAREFUL loosening those little screws, or you'll strip out the Phillips head of them. I'm rooting for you.

4.6LJeepXJ

A lot of times its the Main Relay aka the PGM-fi relay located under the dash on the drives side... if when you try to start the car it cranks and wont start and D4 if lit up its most likely that relay.

primemal

i have changed the relay,the tcu and the i think its called the selinoid of the tranny and after i changed that it worked for a week then flashing d4 light is back
Please some one help me i dont have much money and its all going to parts.

jamoore115

Ive had the same problem wheni first got my car it ran fine but then all of a sudden the d4 light started flashing..wel the car wouldnt start..we checked the plugs and there was oil in the plugs and all around it..so we changed the gasket to the head.gasket..for about a week ive had no problem with it starting and the d4 light wasnt fashing anymore..well about a wekk ater the tranny felt like it was slipping well luckly enough i was near an advanced auto when this was happenin.i pulled over turned off the car and started it back up and it worked fine but i was carefull on how i drove.i talked to the guy and he said to put some lucas fix in the tranny along with new tranny fluid.so i did..well it ran ok for about 2 days then acted up again so i talked to a nother guy and he said it was the tranny solenoids..so i replaced them and the car shifted better and worked perfectly fine..it was the solenoids not shifting into gear when it was suposed to..well it ran fine for about a week but when we check the tranny fluid it smelt burnt..so i dont kno if this was a quincidence that the tranny may be goin out or if it was this the whole time and the other stuff never need to be replace(solenoids.etc..but please if anyone might know whatthe problem could be could you please let me know..like i said we think its the tranny now and i dont know but it still drives a little bit but will totaly slip at times..thank you