1994 Dodge Dakota 3.9L (manual transmission, 2wd) set DTC 35 (Rad fan control relay circuit - according to another post on this site). Unfortunately, the 3.9L Dakota has a viscous drive fan, not an electric fan. What problem would set a DTC 35 in this truck?

A little more background on the situation: The check engine light came on after about eight miles of flatland driving after a cold start (ambient temperature about 80 degrees F). The truck was stopped and the engine turned off and the fluids and belts checked. All checked good. The engine was restarted and the check engine light was off. Completed the remaining six miles to town and errands in town and the light remained off. About ten miles into the return trip home the check engine light came on again. The truck was stopped and the engine turned off. The engine was restarted and the check engine light was off. The check engine light was used to display the DTC after arrival at home. DTC 35 is not listed in the manual for this truck, but I found it at this website.

What is going on?

Thanks,
John

 

Are you sure you read the codes right? Normally 12 and 55 are stored. Which is normal. If your reading the 12 wrong it will look like 3 and you are reading the 5 out of the 55.

Here is a copy and pate from the codes list. https://dodgeforum.com/forum/1st-gen...-96-codes.html

To check the codes stored in the computer:

1. Cycle the ignition key ON-OFF-ON-OFF-ON within 5 seconds. To cycle the ignition key ON means to turn it only as far as it takes to get the radio to come on. It does not mean to turn the engine on.

2. Count the number of times the "check engine" lamp on the instrument panel flashes on and off. The number of flashes represents the code. There is a slight pause between the flashes representing the first and second digits of the code. Longer pauses separate individual codes. For example, flash-flash-flash [pause] flash-flash represents the code 32.

A code of "12" is generally accepted to represent the beginning of codes on our trucks.

A code of "55" represents end of codes. If this is all you get then no error codes are stored in the computer. This is the normal condition.

 

before my o2 sensor broke off completely mine did the same thing a trip down to autozone when it turns on (dont turn your truck off when you get there so it wont go away) and have them check it for free

 

I'm pretty sure the code is 35. The complete sequence from the start is three flashes then a pause, then five flashes (there is a slight hesitation between the third and fourth flash, but not a pause) and a pause, then five flashes and a pause and then a final five flashes. I translate the codes as 35 and 55. The slight hesitation between the third and fourth flashes in the first 5 caused me some concern, but none of the time between flashes is long enough to be a pause.

Thanks for your experience regarding the O2 sensor Auron. I'll check it to see if it is still solidly attached. Autozone is 14 miles away, so I may have to break down and buy a code reader. Driving that far with an unknown cause for the check engine light to be on may be more than I would want to gamble.

Thanks,
John

 

I've never ran my codes without getting a 12 at the start, so are you positive that first 3 isn't a "1...2" and the 5 is something else (like 14, 23, 32 or 41)?

I'd be willing to bet its a 32... something about your description of how it came on screams EGR to me.

 

I bought a code reader, plugged it in, and it displayed DTC 32. It didn't display DTC 12 but I haven't disconnected the battery recently so I wasn't expecting that it would. I don't know what the first three flashes were when I used the check engine light (ready, set, go?) or why the pause between the three and two was shorter than the other pauses. But now that I have the code reader, I don't have to worry about that.

95_318SLT, your suspicion was correct. Now all I have to do is correct the problem. I can do the mechanical tests on the EGR system described in the service manual, but when it comes to the solenoid in the system the service manual refers to a Powertrain Diagnoistics Manual. Unfortunately, I don't have that manual. Diagnoistics manuals weren't listed on the pamphlet that listed the available service manuals. Are the diagnostics manuals available to mere mortals? If they are, where?

And lastly, the O2 sensor is still solidly attached and the wires appear to be in good shape.

Thanks for all the help!
John

 

Like I said before being misread.

Most code readers won't show 12 or 55. Due to them being Normal.