1994 Concorde - Engine light code 35
 

Hi I picked up a good running 1994 Concorde - 3.5L Engine runs Strong and smooth, Tranny shifts tight actually it seems to run great..... Except Engine light comes on after I drive it for about 5 mintues.. but when I shut it off and turn it back on it does not come on again until I drive it for a few minutes then it come on again and stays on until I shut the car off. I did try disconnecting the battery for a few hours and it same thing after I drove it few mile sthe engine service light would come on.

When I did the reading of the codes by turning the key on off etc until it flashes.. I came up with this code 35 which is .. Code 35 - radiator fan relay circuit is open or shorted

BUT all radiator fans are working fine and nothing overheating. I have no idea where to even look for anything.. as all seems to be working fine.

Where is the OBD1 Port? I see the blue plug under the dash but it does not look like any OBD! port I have ever seen. It has 6 plugs but they are 3 on top and 3 on bottom straight horizonal of each other.

Any tips or ideas would be great?

You have found the OBDI port as the 6 pin connector. Very limited information available there at the time compared to today.
In 1996 the "Common" 16 pin OBDII was introduced and mandated, prior to that is was the "wild west and the OEM's could basically do what they wanted.
Trying to find a reader for that old style port may not be worth the effort.
I would suggest the following
Verify all fan operations, low & high by engine temp only (A/C off) Then with A/C on ( would activate by pressures rather than temperatures)
Swap out FAN Relays with "Known good ones". They may "look" good, "click" like they are working but have high resistance or other internal problems.
Link to diagrams and locations
https://knigaproavto.ru/shemy/en/chr...-97_fuses.html
Good luck and let us know what you find

Looking to be certain you are reading the flashes correctly. The flash codes always begin with 1-2 and end with 5-5 with the real codes between. Use the timing of the 1-2 flashes, 1 flash - short pause - 2 flashes - long pause - <next code first digit flash> to get the pacing of the flashes and codes.

Code '12' is a battery disconnect and have always seen '12' whenever pulling codes. I consider '12' as the start of codes. Code '55' is the end of codes. The codes between these are the important stuff.

This link goes into great detail - https://www.allpar.com/threads/troubleshooting-chrysler-two-digit-computer-fault-codes.229056/

If I had to SWAG, you may be reading the 1-2 flash as a '3' with the '5' being either a '14' or a '23'. This is just a guess on my part.

I will upload a short video of the flashing codes if someone could double check what I am reading I will post the video here once uploaded... and thanks everyone for responding. Thus far appreciate it.

Also the dreaded digital heater control panel. That seems people always have issues with. Well when i bought the car the owner said they already swapped out that control panel once.. and well a couple days after I had it the stupid thing went out again did the turn to high defrosters on high heat and fan.. and nothing else. I have tried to take out reset all plugs etc and no go. So was wondering is their a way to swap this digital control panel out with another type (that does not have so many issues) OR pu tin its place a manual controlled unit and get rid of the digital one or is there an updated digital one that I can replace it with. I just bought another OEM one off eBay but if it only last a year before it has to be replaced again would rather just change it out to something else more reliable if possible/

I will upload the video clip later today on the engine lights.. .

OK here is the video with the ignition in code reading mode! Now that I look at it again maybe its code 32?

If someone could double check for me I would appreciate it what code (s) are you seeing?. I'm a female but I am mechanically inclined. :)


Thank you..

Looks like code 3 2 that is EGR related. The EGR valve is vacuum controlled on these engines. Maybe if you are lucky inspecting/ replacing dried brittle hoses may fix the problem.
Not sure how much you drive or want to spend on a 94 car. If it runs ok and just drive occasionally let it be. (Valve may be stuck closed)
If it stalls and runs rough, valve may be stuck open and would need to be fixed.
State inspection may also be a factor.

Hi Seems to run fine.. Not putting a lot o money in it. Its a beater with heater until my daughter can save for the car she wants. We do not have state inspections here. I will check out some vacuum lines. The engine light only come on after driving it for a couple miles. So I am guessing a vacuum leak somewhere. Thank you!

I can get the valve assembly for under $50 so if its not a vacuum hose will just replace/repair myself.

Thanks everyone..

My arithmetic skills are suspect, 3-2 is also 5 - duh...

The egr only comes into play at highway speeds. It lets in some exhaust gas into the intake plenum to lower the temp of combustion which reduces the amount of nitrogen oxides produced. Since it is not stalling or idling poorly is it likely stuck closed (or not opening) as FIREM noted and will not affect engine running or mileage. It is tested after the engine has warmed up and that is why you see the lamp light after 5 minutes. Testing is opening the egr valve briefly and seeing a corresponding response from the O2 sensor.

It is possible it is the vacuum hose from the egr valve to the intake manifold has failed - good place to start. The egr is a pita to replace as it attaches on the back of the intake plenum, under the plastic cowling. There are 2 tubes at the plenum and the erg valve is down below on the right exhaust manifold. If you do replace the egr, removing the plastic cowling will give more room to work.