Today I was driving on the highway and all of the sudden, the enige surged a little and the ABS and battery light came on. I've stopped the engine and started it again, the engine starts easily.

I also have reset the management computer by removing the mass cable from the battery for several hours, but starting the car gives directly a lit ABS and battery light. The battery light isn't dim.

Could someone give me some theory on why both lights came on at the same time, or maybe explain to me how to search for the problem by excluding things?

  • You should have read the OBD codes before clearing the memory.
    – Moab
    May 4, 2018 at 22:08
  • Welcome to Motor Vehicle Maintenance & Repair! If the ABS light continues to shine, there's a persistent problem with the ABS system. You'll need an ABS capable code reader to point you in a direction. Most OBDII readers do not cover ABS (nor SRS systems for that matter). The guys at retail parts stores won't be able to help either. May 4, 2018 at 23:34

2 Answers 2


This is the order in which I would exclude possibilities.

  1. Check the charging system for either too high or too low of voltage. This is the foundation of everything electrical on the car. Typically it should be between 13 and 15 volts.

  2. Check all fuses. If any are blown, replace and check again.

  3. Retreivel the abs code(s) by grounding the L terminal at the diagnostic link connector with the key on and count the flashes that follow the 1 and 2 (12) flash.

    Verifying what is good first, will be more effective than coming up with theories to why they both happened at the same time.

  • Sorry for my messy triple posting, but now I looked in to the service manual, I did see 'check alternator L terminal voltage', where in my case, this 'L' is 'C/U connector pin 15. Page BR-98 if you happpen to own a service manual for a B13 Nissan. So I didn't understood what you wrote, but that is probably that you have the experience which I don't have. Many thanks. May 6, 2018 at 17:38

To the moderators, if I have should replied instead of answering, I'm sorry I was about 1200 characters short and this is my first post and I believe it can will help people finding their way if they have the ABS and battery light lit

Thank you for your answer. I've had no experience with alternator voltages, but I measured 12.4 volts when not operating and 12.3 volts while the engine was running.

I also checked for the alternator belt if it had enough tention and it did.

While I suspect now that the alternator is going or already gone, I did check the fuses and all seemed okay. However I was able to lookup in a service manual for this model (Nissan B13), and it had an diagnostic procedure. While I first did test my ABS by breaking hard enough, I wasn't expecting this would be a valuable clue, since the diagnostic procedure stated that if the ABS light has come on, I should check the diagnostic LED for flash codes, but the diagnosic procedure mentionend a burning ABS light, together with working ABS when braking, with no flashes of the ABS management computer LED, it said it would be a faulty alternator. This LED did flash once when I turned the ignition, so I am sure it is a working LED.

All in all I have found two clues, a too low voltage while the alternator is running and a diagnostic that ABS is working and no LED flash code it is saying faulty alternator. I'll now start looking in to looking for a second hand, or repair and replace.

I want to mention this is an OBD (OBDI) car, there are no fault codes from OBD I know because I use Nissan Datascan (however I didn't check for it either) but then the service manual would have pointed to the Nissan dealers testing computer.

I am happy with your answers since this gives me more confidence to repair it myself, I am not aware for my Nissan of grounding the L terminal, I also don't know if it is on my car or not and the engine's management computer, OBD connector both have no LED, just the ABS computer has a LED.

  • I noticed my answer now came before the answer I valued by clicking '^', but I have not enough reputation. May 6, 2018 at 17:25
  • In the end I've found a diagnostic procedure (car is dated 1992), where it said, no flashing ABS light, but ABS dash light on > faulty altenator. And replacing made the battery light and ABS light stay off after starting the car. Jun 24, 2018 at 15:32
  • If your alternator isn't faulty and you might want to check this first, sanding terminal grounding might help. If the ABS computer sees a too high voltage difference, that is the way this 1992 car might set the ABS light lit. If you sand your terminals make sure you don't miss one because that might give other lights, readers with more modern cars must keep in mind it might work different (like go to garage warning or other obscure for the driver error output) but this are the basics. Apr 20, 2019 at 19:00

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