Hyundai Forums banner

1 - 20 of 40 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Good day. I have a no start condition (but does turn over) on my 2006 Hyundai Tucson. 2.0 L I4, 5 speed manual, 4WD, Canadian model.

Symptoms:
  • The fuel pump signal does not change whether the key is in LOCK, ACC, ON or START. I know this because I removed the back seat bottom on the driver’s side and hooked a multimeter set to DC volts to each possible combination of the 4 pins. A couple of the pins read 12V all the time, but none changed as my assistant turned the key as described earlier.
  • There is no spark. I know this because I removed a spark plug wire from the spark plug, then touched a screwdriver to it and the lifting hook on the front of the engine. When my assistant ran the starter and the engine turned over, there was no visible or audible spark.
  • The Crankshaft Position Sensor (CKS) electrical connector had oil inside of it.
  • I switched the fuel pump relay with the AC relay to no effect.
  • No fuses are blown for fuel pump, ECU, immobilizer
  • I tried both sets of keys
  • The car ran fine when it was parked in its current spot a week ago. A buyer of the car was taking it for a test drive (which went well enough for her to agree to buy it; I just need to fix it so she can drive it home)
  • These symptoms appeared after parking it for a week, and the battery being weak when attempting to start. I have since recharged the battery fully with an AC 15A charger. I also unplugged the battery overnight (~12 hours) in an attempt to reset the electronics, but this did not fix the issue.
  • The fuel gauge registers ¾ tank, and I did fill it recently before parking it.
  • My ScanGauge II shows 0 RPM while I am cranking the engine (it definitely turns over).
  • I felt the occasional stumble while driving before this issue occurred, but it was so brief I couldn’t be sure something actually happened.
  • There is an aftermarket (circa 2005) remote start and an aftermarket cruise control installed.

Questions:
  • Could a bad CKS cause the car to not run the fuel pump when the key is in ON but not START? I would think the car would always pressurize the fuel system before attempting to start.
  • Is there a fuel pump solenoid/shutoff like on the Santa Fe that may need to be reset? If so, where is it?
  • Is there a hidden fuse/circuit breaker for anything drivetrain related not in the 2 main fuse boxes?
  • Does the output for the fuel pump change when the connector is unplugged? (2-way communication?)
  • Can anyone suggest other checks?

Thank you for your time, I appreciate any help.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,596 Posts
If there is no spark and no fuel pump operation during crank the first thing to check is the power supply & ground at the crank position sensor.

Disconnect the sensor and connect a voltmeter across the two outside terminals on the sensor's harness connector. Don't push the meter probes into the terminals or you might damage them. Just touch the probes onto the terminals. Make sure you get 12V while the ignition is switched on.

 

Attachments

·
Registered
Joined
·
8 Posts
Discussion Starter #3
I tried that, and found a value of 5 or 8 volts (I can't remember exactly, but it wasn't 12V) while the key was turned to "ON". Does this normally mean trouble with the computer, or just a loose/corroded wire?

Thanks Autospark.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,596 Posts
Does this normally mean trouble with the computer, or just a loose/corroded wire?
Don't worry, it won't be a problem with the computer but you'll need to do a further test to see if it's the power supply or the ground that's causing the low voltage.

Connect the black probe of your meter to battery negative and check the voltage on the two outside terminals of the harness connector with the ignition on. If the power supply is good you will get 12V on one. Next connect the red meter probe to battery positive and use the black probe to check the ground terminal on the connector. If the ground is good you'll get 12V. Which ever terminal gives you the lower voltage is the one with the problem.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #5
I checked, and both terminals on the connector, and both read 12V when touching the positive terminal, so both are grounded. Possibly a short somewhere?
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,596 Posts
I checked, and both terminals on the connector, and both read 12V when touching the positive terminal, so both are grounded. Possibly a short somewhere?
Did you have the ignition on for the second test? It isn't possible to have 5~8V in the first test then have both wires show 12V in the second. If both wires are ground where did the 5~8V come from?
 

·
Registered
Joined
·
8 Posts
Discussion Starter #7
I was mistaken earlier about which terminal had 5V. The Center terminal reads 5V with the ignition switch ON, but both end terminals read as ground.

Earlier, you said that one outer terminal was positive and one negative. I got both negative, so I'm wondering if that's a symptom of a short or of the computer not sending the signal for some reason?

Don't worry, it won't be a problem with the computer but you'll need to do a further test to see if it's the power supply or the ground that's causing the low voltage.

Connect the black probe of your meter to battery negative and check the voltage on the two outside terminals of the harness connector with the ignition on. If the power supply is good you will get 12V on one. Next connect the red meter probe to battery positive and use the black probe to check the ground terminal on the connector. If the ground is good you'll get 12V. Which ever terminal gives you the lower voltage is the one with the problem.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,596 Posts
I was mistaken earlier about which terminal had 5V. The Center terminal reads 5V with the ignition switch ON, but both end terminals read as ground.
OK, that makes more sense. Since the 12V supply to the sensor is missing the next thing to check is the fuses on the engine bay fusebox. I don't have the diagram to hand but I'm pretty sure there's a fuse specifically for the engine sensors on the Tucson, probably marked SNSR on the fusebox cover. Check that fuse and if it isn't blown check to see if there's 12V being supplied to the fuse when the ignition is on.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #9
I checked the SNSR fuse - good. It is not receiving 12V; it's 0.3V at best. Could be a wiring issue, anything else to check?


Thanks
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,596 Posts
anything else to check?
Yeah, next thing I'd suggest is removing the engine control relay (photo below) and check the voltages on each of the terminals of the relay socket in the fusebox. Two of the terminals should have 12V. If not check the main ECU fuselink (photo again). If there is 12V at the relay, next use a link wire to bridge the two terminals on the relay socket as shown in the diagram below. With the link fitted, recheck the voltage at the SNSR fuse.

Let me know what you find and we'll decide then where to go next.



 

Attachments

·
Registered
Joined
·
8 Posts
Discussion Starter #11
Yeah, next thing I'd suggest is removing the engine control relay (photo below) and check the voltages on each of the terminals of the relay socket in the fusebox. Two of the terminals should have 12V. If not check the main ECU fuselink (photo again). If there is 12V at the relay, next use a link wire to bridge the two terminals on the relay socket as shown in the diagram below. With the link fitted, recheck the voltage at the SNSR fuse.

Let me know what you find and we'll decide then where to go next.



Solved! There was a broken (corroded) wire near the firewall, coming from the fuse box.

Autospark, thank you for all the help. Everything you suggested pointed me the right direction, though I must admit to giving up too early. I was busy, so I had the auto club tow it to the nearest city (300 km) for repair.
 

·
Registered
Joined
·
8 Posts
I have completed all of these steps and checking the snsr fuse I have 12 volts. Should I order the relay ?
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,596 Posts
Should I order the relay ?
Not if you have 12V being supplied to the SNSR fuse. That means the relay is working.

Do you have spark at the plugs? Is the fuel pump switching on DURING CRANK?? What engine are we working with???
 

·
Registered
Joined
·
8 Posts
Not if you have 12V being supplied to the SNSR fuse. That means the relay is working.

Do you have spark at the plugs? Is the fuel pump switching on DURING CRANK?? What engine are we working with???
I am working on a 2.0 L 4 cylinder

I do not have 12volts at the snsr fuse but when I followed the above posts, I tested the terminals at the relay and had 12 volts. I then jump the terminals as shown in the photo above. At that time I had 12 volts at the snsr fuse. Was wondering if I should be testing further or order the relay ?
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
15,596 Posts
Was wondering if I should be testing further or order the relay ?
I think you should test a little further before ordering a relay. One very simple test you could do to confirm that you need a new relay is to just swap the engine control relay with the starter relay. With the relays swapped over, see if the engine will crank. If it does you know the relay itself is OK meaning it's just not being energized/switched on by the engine PCM, probably because the wire between the PCM and the relay is open circuit/broken.

 

Attachments

·
Registered
Joined
·
8 Posts
I have switched out the relays and the car still turns over. What is the easiest way to follow the wire or determine that there is a actual break in the wire. Color codes, wire diagrams would be a great help. Is there a way to test the ECM to make sure that is not the problem?
 
1 - 20 of 40 Posts
Top