Hyundai Forums banner

1 - 3 of 3 Posts

2 Posts
Discussion Starter #1 (Edited)
2002 Hyundai Sonata 4 Cylinders 2.4L FI DOHC
VIN #: KMHWF25S52A536515
Crank no start, no spark, strange electrical issues and low voltage in places.

Where I am now I can't get the car to start back up. It just cranks and cranks and cranks. The fuel pump does not come on and I have no spark.

I thought I would post for help and any help I can get would be greatly appreciated. Sorry to be so long winded I like to be thorough. I can not get my nephews car to a shop right now because of COVID and the closest shop I can tow to is 2 towns over so it's just me right now. I am not a great mechanic. I have fixed different things over the years but I am mainly a computer nerd and handyman. I do like to learn though and will listen. I need to get his car running for him because he got his first job and starts soon. I raise him and I either need to get his car running or let him drive mine while I figure it out.

I can give a brief history about the car so that it may help. My dad took great care of the car. His fuel pump and catalytic converter went bad in 2016. Before him and my mom passed away in 2016 and 2017 he replaced both as well as the coils. I'm sure he probably did some other things that I am unsure of, he was the mechanic. After he passed away no one drove it for a while. Him and my mom raised my nephew and the car was suppose to go to him for when he started driving. Last year my sister "stole" it and only had it for about 2 weeks. I found it and when I went to get it back it was tore apart on the inside. I drove it home and the performance was HORRIBLE. It was about out of gas though so I stopped and put a few dollars in it to make it home. Its sat at my house for about about a year before I could mess with it and when I did the battery was dead. I got a new battery and it started right up. It died after about 5-10 minutes while I was checking things (mainly fluids like oil and transmission fluid) but I just assumed it ran out of gas. I recently put gas in it and I can see from taking the fuel pump out it should have plenty of gas so I don't think that is why it died. Maybe i hit something or shook something loose. I will probably be confusing and I am very, very sorry. I just kind of went on an adventure of learning and trying to figure out what was going on. My dad had a spare cam shaft sensor so I wanted to go ahead and replace it but the pigtail disintegrated when I unhooked it. I butt capped the wires back to the pigtail until a new one comes. Can not replace cam sensor until it gets here. I have been using an 8 page wiring diagram that I got here on a reply from member AUTOSPARK on a different post (thank you!)

Parts replaced so far:
  1. Engine Control Relay
Here are the things that I know, checked or tried:
  1. No check engine light comes on at any time.
  2. BlueDriver OBD2 bluetooth scanner won't connect to scan for codes.
  3. Power door locks, windows, radio, AC and at least clock didn't seem to be working before I took out the radio console to get to the engine control relay.
  4. There is no spark on either coil
  5. Fuel pump does not come on when the key is ON like it use to
  6. Fuel pump connector not getting any voltage on fuel pump connector (i may have seen the voltage move after replacing the ECR but don't hold me to it).
  7. Multipurpose check connector M04 not getting voltage on pin 9 for fuel pump but is getting constant 12v at pin 8. (see attachment2.jpg)
  8. Engine Control Relay is getting constant 12v.
  9. Ignition switch getting constant 12v.
  10. Cam sensor getting no voltage when key is ON and then low voltage around 0.06 to 0.26 when cranking (i tested this because my dad had a brand new cam sensor in the car he didnt use so I figured I would replace it)
  11. Crank sensor getting no voltage when keyis ON and then low voltage around 0.02 to 0.20 cranking (maybe not suppose to get 12v?)
  12. MAF getting low voltage 0.04 when key is ON (maybe not suppose to get 12v?)
  13. Crank sensor and MAF wires look good from what I can see.
  14. Almost all of the fuses in the fuse box inside the car are getting 12v and none are blown.
  15. I have went over the engine fuse box 10 times and no fuses are blown and wires look good. I have cleaned the battery cables and checked the ground wire. Went over the fuses that seemed obvious to me 20 times.
  16. Tested all of the relays in the engine compartment fuse box and inside fuse box to hear switching and resistance with multi meter.
  17. ECM fuse 10A (#29), ECU RLY 30A (#7), MAIN fuse 30A (#24) has constant 12v
  18. Injector fuse 10A (#4) does not have 12v (more like 0.10 when cranking). ECU fuse 15A (#10) does not have 12v (again more like 0.10) (see attachment1.jpg)
  19. I don't know what it could have been and I do not see anything but it's strange to me that it shut down last when I was checking the oil and looking over the engine. Almost as if I knocked something lose.
Here are the things that I am confused on:

  1. Where does the cam sensor and the crank sensor get their power from? From these 8 page diagrams I can't tell. I am trying to understand so I can test my way through and see if whatever powers them has power. I think it is the ECU but I am not sure yet.
  2. Do things like the cam sensor and ECU (ECM? PCB?) get power after the crank sensor is successfull?
  3. Is there a good, best way to test the ECU to see if that is my problem? And if it ends up being the ECU can I get a used one from the same year, make and model and it be plug n play or does it HAVE to be reprogrammed?
  4. Should I go ahead and replace the crank position sensor?
Anyone have any thoughts or suggestions? I am still learning and believe it or not a lot of these things I have learned just the past month. I will try to think of anything else that I have done or checked. I probably have left many things out but it's been a lot! Thanks for your time.


Drives : Nissan NV200 Flies : Rans S6ES
14,698 Posts
Sorry @lJesterl , I've only just come across your post. Have you managed to fix the fault yet?

Here are the things that I am confused on:
1.)Power for the sensors comes from the EGR fuse....

2.) The ECU and the sensors should be supplied with power whenever the ignition is switched on.
3.) You can't really test the ECU. But you can check it's power supplies, grounds and input signals. If everything is good on the input but there is nothing on the output (to trigger the fuel pump, injectors, etc) you can assume the ECU is faulty. But ECU's very rarely fail.
4.) If the sensor power supply, ground & signal voltage all check out OK, then yes, replace the sensor.

If I helped you fix it, why not...

Your support is greatly appreciated
1 - 3 of 3 Posts