97 EB 'Check ALL Lamps' after LED switch

I replaced all my 1997 Explorer Eddie Bauer lighting with LED lights. Brake, tail, reverse, turn, interior and the headlights are now HID bi-xenon everything but the high mount 3rd brake light and instrument panel/dash is now LED.

Prior to replacing the stock bulbs with these LED's I had no messages or warning about lamps being out but after I replaced the stock lamps with LED I am getting "Check Tail Lamps" "Check Brake Lamps" and "Check Head Lamps" in the message center even though all lamps/lights/bulbs are functioning properly.

Am I getting these messages because LED doesn't draw the same amount of power as the stock bulbs and it's throwing off the computer/system check or do I have a faulty module? Not sure what the process of elimination would be or what to check first to possibly fix this issue.

This isn't a dire issue but it is rather annoying hearing the multiple errors and having the reset them at every startup system check. I am rather fond of LED for the power saving and aesthetic upgrade however I am debating on keeping my HID headlight conversion kit.

Any suggestions? Thanks!

 

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Yeah, your Lamp Out module looks for current or voltage. It was actually decontented after 97 I believe. I believe you can remove it or possibly add resistors. It is rare for a LED to go out anyway. The LOM can fail and make your headlights stop working too.

 

Yep, you either need resistors, or you needed to purchase LED lights that have them built-in. Most of the places that sell LED lights should be able to sell you resistors, also, or lights that come with them.

On my newer vehicle (I also own a 2012 VW Golf R), I can code out the bulb out error using a tuning program I have. As for your truck, I don't know if Tweecer or similar could do that. If available for your 2nd gen, that's an option too...

 

The message center is its own module and invisible to any scan tool. Another option may be an Arduino, you could probably have it watch LED current and output a resistance if the bulb works. Chances of a LED going out (I believe) is quite slim.

 

I have a 99 Eddie Bauer and have changed headlights, brake lights, interior and running board lights to LED but I’ve not got any error messages, I wonder if it’s the brand of bulbs?

 

Factory LED lighting designs are fairly reliable but aftermarket chinese junk is often less reliable than the incan bulb it replaced, due to trying to produce more light with fewer LEDs to keep cost low, and the limited amount of space to heatsink in some bulb form factors.

Regardless, one possibility might be modifying the LOM (lamp out module). While re-enginnering it to detect the lower current of the LED bulbs is beyond reasonable due to the time, modification efforts, and unknown variables such as individual bulb currents of these new LED bulbs, the easier solution is to merely disconnect the output that's signaling that the specific bulb circuits have a problem. This should literally be as easy as cutting the traces on the circuit board with a knife. I'll go into more detail in my next post.

 

You don't necessarily need to add resistors to all the bulbs. It's often more intrusive to the wiring, costs more for custom made modules, and wastes power. Besides that (usually) defeats the bulb-out sensing the same as doing it another way described below.

First see the following topic, if you wish you can rewire your lights without the LOM module, cut the wires, solder and insulate them. It seems a bit intrusive to me so I researched the remainder of this post.
Read to bypass ur lom!!!!

If your LOM board is not the same as I've pictured and at the following link, then I have wasted a little of my time (but not too much, when you get a look at the pic below you'll realize I did this quick 'n dirty), but the same general principle would apply:
Ford Explorer LOM Module

This board is based on an LM1946N 5 channel comparator chip. Datasheet: National Semiconductor - datasheet pdf

It is using 3 of the 5 channels, 1, 3, and 4. On the picture below I've done a rough trace of 2 of the 3 outputs sent to the console display unit just to help anyone follow along. This chip measures a voltage drop across the big resistors seen on the right side of the picture below and if the drop is too small it outputs a signal. If you merely cut the signal lines then it can't signal the bulb circuit is using too little current (bulb out or in this case is lower power LED bulb(s)).

The bottom half of the picture below is a mirror image and rotated 180' so it corresponds to the correctly oriented top half of the picture, making it easier to trace. You can see on the picture where the 3 channels used, trace over to the connector pins. You should be able to just cut those 3 traces to deactivate the warning.

The more tedious method of trying to keep it working would be based on mathematically arriving at altered resistor values and making out a complete schematic of the board. The simplest first attempt would be measure your original bulb current, measure your LED bulb current, and divide original by LED. Suppose the product of that division is 10, meaning the LED bulb uses 1/10th the current. You would then measure (or read from the color stripes) the resistance of the respective sense resistor (row of the 7 largest in the pic, most channels have two resistors in series) for that bulb, multiply that by the product above (10) to get the new resistor value you need to put in, in place of the originals... or plug more numbers into the datasheet equations to alter the other resistor values which would gain a little efficiency. It "might" not be that simple, adjusting the current sense resistors might also require adjusting the others, so it's easier to just cut the traces if you just want the warning to go away.

If your LOM board looks different, it is still likely to be based on a similar principle where it measures voltage drop across resistors and outputs a signal on thin traces (since the bulb input and output current have to use thicker traces) so you'd cut those thin traces. No guarantees there, with a different board layout unless you trace the circuit (since I can't see it).

If you later want it working with stock incan bulbs again (working meaning indicating if they burn out, they will still work to make light either way), you'd just take some wire and solder it between the first two solder points on both ends of where you cut the traces.



While we're looking at it anyway, those big sense resistors' solder joints are a common failure point on this module. If yours fails you might want to try resoldering them.

 

Thanks for all this great input and feedback thus far! Just to clarify there's no issue with the new LED bulbs being blown or not working as they are all burning and functioning properly. Part of my reasoning for upgrading to LED was for the longevity of LED bulb life. I highly doubt these bulbs will fail in the next 5 or 10 years. Just wanted to clarify that all the LED bulbs are not burned out or failing/malfunctioning at the moment as all lights including the Bi-Xenon HID headlight conversion kit are working and functioning properly.

The vehicle is undergoing maintenance at the shop right now but when I have it back in my possession in the next couple days I will try some of these suggestions. The first and easiest method is to replace the current tail/turn/reverse LED bulbs with resistor-included sets rather than modifying the LOM however if the headlight lamp warning message is still showing after resolving the brake and tail lamp errors I will end up moving forward with modifying the LOM. Since the headlights are HID (Bi-Xenon) I can't modify those bulbs directly without rolling back to the original 9007 Halogen bulbs.

I will have some updates for you all after Thanksgiving to which I wish you all a happy turkey day and again appreciate the feedback and input! J_C thanks for the breakdown of the LOM modification process, I will take a look at my module later this week and post back with my findings. I have a feeling I will be proceeding with this to silence the headlight lamp message post HID conversion so thanks again for that awesome detailed LOM breakdown!

 

Posting an update. Hope all had a decent holiday!

After doing some research into several different options I finally decided to try the easiest solution (aside from returning back to the stock lamp bulbs) by implementing resistors and decoders.

For the HID conversion kit I've ordered Resistor Kit Relay Harness Adapter Anti Flicker Error Decoder,

Spoiler

for the tail/brake LED's I'm going to try a couple different options the first being 3157 3528 80-LED Vehicle Car Error Free LED replacement bulbs

Spoiler

and as a last resort I'll try the Load Resistor Fix LED Light Bulb Hyper Flash Error.

Spoiler

For the turn signal I've ordered LED Flasher Relay Fix Hyper Flash Turn Signal Decoder.

Spoiler

Should that fail then I'll order more of the 80SMD Error LED bulb mentioned above.

It will be next week before all these pieces are delivered but I will post another update once I have installed everything!

 

I think I'll just stick with my old fashioned incandescent bulbs, thanks.

 

^ Yeah my '98 3rd brake light is the only thing I would have been tempted to change to LED... except that Ford already did it for my model year. I did think about adding a cargo bay light but not as small a change as swapping an LED retrofit bulb into the existing housing, which is often no brighter even though it creates glare which fools the eye into thinking it is. If I bother to do it then I have the parts to make it ridiculously bright as a separate light that I'd pull out if I ever get rid of the vehicle... except I need to figure out some kind of diffuser cover for it, might buy some cheap chinese junk light off ebay just to get a cover and scrap the rest of the ebay light.

 

I replaced the guts of my '97's inoperative 3rd brake light with an LED strip. Pretty easy to do. IIRC it cost me around $12 for a waterproof, self adhesive cut-able strip.