This 2001 Honda Civic came in with a multitude of problems one of which was a code P1298 stored for an ELD fault (electric load detector circuit input high). I had never had to actually test one of these before although I knew that they existed. The ELD sends a signal to the engine control computer so that the computer can adjust the alternator output in relation to power consumption. The ELD is located in the underhood fuse box. I am pointing to it with my screw driver.
To test the ELD I had to lift the underhood fuse box and remove the bottom cover. Once removed I could access the wiring for the ELD. The wire on the far right of the connector is power supply (battery voltage).
The wire in the middle of the connector is battery ground.
The wire on the far left of the connector is a five volt signal sent from the computer. The ELD will pull the voltage lower with increased system load and should vary with a change in load. For example if the blower or headlights are turned on it should drop. This particular unit was stuck at 3.81 volts and would not change with no loads or full loads applied. If the voltage had been near zero I would have had to unplug the connector and see if the five volt reference signal was being sent by the computer and wiring.
After testing and finding a faulty ELD, it was very easy to change. I removed the four adjoining phillips headed screws that held the two PAL fuses in place.
I released the latch on the harness connector and unplugged the connector.
With the wiring removed I simply lifted the unit. Slid the bar out and installed the new unit.
Below are a couple of pictures of the actual ELD part from Honda.
You were right Sparky, after replacing the ELD. My 2002 Civic GX still had multiple misfires so i sent the injectors in to have them rebuilt by GB engineering. They were fast and i had the injectors back with new washers and seals. I replaced both high and low pressure fuel filters. The car started right up and idle great. I was able to determine the cause of the failed ELD was due to a bad alternator that was shorting when wet and charging at 25 volts when it should be at 15 volts.
The maintenance light comes on at predetermined mileages and the ELD and battery have no effect on it. The SES or check engine light can be turned on by the ELD fault.
My bf had a 2001 Honda CIVIC …(oops) He got into a “minor” accident and hit his passenger front bumper. I replaced his bumper,grill and popped the dent put of his fender. He only had minor frame damage bit not from the naked eye,about a few days later his maintenance req. Light came on and off and while driving on the freeway his cars rpms jumped about 1,000 and went straight to 0 and the car shut off,about a few moments later (with out touching the ignition) the car turned back on. I ran the codes on his car came up with only one p1298 I started searching forums and found yours. O went to Honda dealership the part cost $41.00 and changed it when I went to reset the battery I noticed the metal bar that secures the batterie had snapped shifted and was not grounding out the ground and melted the whole top of the batterie. I fixed that. And told him to get a new one even tho this one is operating fine we are getting one tommarow. Now my question is – could the battery be the cause of the maintenance light being on still ? Thank u for your time -Ciara
Assuming that you were testing voltage on the same wire I was and applying the loads, then the ELD is faulty.I think there is a very small chance that it will be contributing to your engine running problem though. Let everyone know if replacing it corrects that problem or not.
Sparky, Thanks for the great posts. I had the same issue with the P1298 code but before I tested my ELD I checked to make sure the spark plugs were tighten to the right torque of 13lbs. I read on your other posts that an improperly installed spark plug could make the car run rough. Before I forget, my 2002 civic GX also has 140000 miles and the valves were recently adjusted. The timing belt kit (belts, water pump, seals, tensioner, and ngk plugs) were replaced at 115000 miles. This car runs great on the freeway but studders starting of at the light so i also replaced the coils.
I tested the ELD under load with the AC, blower, Headlights and rear window defrost on. The voltage only fluctuated from 4.443 to 4.442 volts. You mentioned that it should be at 5 volts … does this mean that the ELD is stuck or is 4.442 within tolerance.