D4 flashing

[h22aAccord93]

I have an automatic 1993 Accord LX, and sometimes when I am going to turn on the car. I see the gear D4 flashing on the cluster and the car won't turn on. Before I turn it on I hear like a clicking sound I think is coming from the ignition and that is when I know won't turn on the car because that click is the one I always hear before the D4 starting flashing and I can't be able to turn the car on. One way I wait for the D4 to stop flashing it leave the car for like 30mins to an hour and then it turns on.

***ANYONE KNOW WHAT IS CAUSING THIS PROBLEM?!?!??***

[h22aAccord93]

bump

[mrhonda]

A bad TCU will cause this. I've seen this a couple times on these. Occassionally, when the TCU goes bad it shorts out internally and causes some of the relays under the dash to go crazy....don't ask. TCU is almost always the culprit.

[iamanonymous]

A bad TCU will cause this. I've seen this a couple times on these. Occassionally, when the TCU goes bad it shorts out internally and causes some of the relays under the dash to go crazy....don't ask. TCU is almost always the culprit.

actually, it means your car is going to explode.
no, it means you need a tranny swap.
ok ok. reset you ecu and check for codes i believe tcus have trouble codes as well
btw im in a strange mood

[IBCNYA]

yeah mine does this too....good thing im selling it huh????

[xfactortype1]

try this instead..worth a shot.

hey it may be a bad coolant temperature sensor...the hard to get coolant sensor directly underneath your distributor. the front coolaant sensor switch control the hot cold guage inside dash board. if you dont believe me unplug it when car is warm and the needle should go to cold. plug it back in and itll should go back to half. THE SENSOR IM TALKING ABOUT IS UNDERNEATH THE DIZZY. if you unplug this while your car ir running it will stall, and your d4 light will flash. yes a majority of the time the d4 light indicates a tranmission problem, but since you say your having trouble starting the car..im leaning towards a faulty coolant temperature switch.

other possibilites
faulty main relay, fuel pump, fuel pump relay, or bad ignition switch.

wellthat just my opinion

goodluck anyway

[h22aAccord93]

From this pic ^ can u tell me where the engine sensor is because I am pretty sure it might be this

[h22aAccord93]

is this the sensor your talking about because u talked about un-plugging

[WiKKeDV16]

extra..




shhhh. lol..


i believe thats the Coolant temp sensor hes talking about

[Gemini]

That happened to me once when I blew a radiator hose and my car didnt having any fluid left so car start to slow down, and the D4 start flashing...so I think its the coolant temp switch lke he said. Just my 2 cents.

[xfactortype1]

yes in wikked 1st pic its the one on the left still plugged in. the one on the right (that is unplugged) is the sensor for the Hot to Cold guage in the car dashboard. the haynes manual i have calls it coolant switch D for the ECM.
i know it confusing cuz theres 4 switches/sensors on the dizzy end of the cylinder.

switch A-- is a radiator fan switch (located on the right end cylinder head from where the longer radiator hose goes into the block behind the dizzy. it mounted to the housing. should kick on radiator which is the drivers side fan, on at about 189-199 degrees)

switch B-- is the condensor fan switch ( located on the front of engine block just to left of exhaust header. it is mounted to the housing thatthe upper radiator hose exit the cylinder head this should kick on at about 212-232 degrees. this runs the passengers side a/c fan.

switch C-- this is the coolant temp sender switch ( like i said it controls the hot /cold guage inside your dash board. your car will run fine without plugged in, but its cheap and very easy to replace.

switch D-- this is the coolant temperature sensor. ( this send info to your ecm to help adjust for air fuel ratios in the fuel injection system. which is why i suspect it is this sensor and why you are having alot of trouble starting your car and getting d4 flashing

well i hope this helped for some and others. i just woke up.. time for coffee

[mrhonda]

this is mostly true....that is in fact the coolant temp sensor he is pointing to, and it is an input for the TCU, so yes it is possible that this is the problem.

However, the temp gauge on the dash recieves its signal from the coolant temp sending unit which is the small single-wire sensor located to the right of the coolant temp sensor.

[mrhonda]

oh...oops, I guess I missed that part. So looks like we're all on the same page then.

[h22aAccord93]

ok I see, so before i try to turn on the car i am going to disconnect that sensor

[Masamune]

I honestly have no clue what it is. Recently though, I noticed that my shifter (I have an auto too, BTW) is getting more stubborn to change between the tranny modes (i.e. Park, Neutral, Reverse etc. etc.) I parked my car once and didn't quite hit park on the shifter. Well when I went to start my car the next day, all it did was click, like you described and would even turn. I grabbed the shifter and shoved it as hard as I could into park. Turned the key and the car starts right back up. Maybe this'll help in some way, IDK...