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Roy, import/domestic specialest
Category: Car
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Experience:  ASE master tech for 40 years
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Hyundai Santa Fe GLS: I have a 2003 Santa Fe with a 3.5L XG350

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I have a 2003 Santa Fe with a 3.5L XG350 engine in it. It developed a two cylinder misfire suddenly. Then a few days later the engine stopped running and would not start. It cranks fine but won't even begin to fire. All the fuses are good. BTW, I changed the timing belt for the second time about 10,000 miles ago.
good evening my name is XXXXX XXXXX I will assist you tonight

Why did you change the belt so soon???

the crank sensor is suspect here. do you have a tach on the dashboard???

Customer: replied 3 years ago.

The timing belt was changed for the second time at about 120k miles. Yes it has a tach.

ok, does the tach move while you are cranking the motor???

Customer: replied 3 years ago.

I don't know if the tach moves or not. I'll have to get back to you on that.

ok, that will help determining if the crank sensor is working

Roy and 7 other Car Specialists are ready to help you
Customer: replied 3 years ago.

I'll check the tach response ASAP.

ok, I will be here tonight

Customer: replied 3 years ago.

When I engage the starter, the tach needle never moves.

ok, good sign of the crank sensor failure. I would start there.

Customer: replied 3 years ago.

Changed the crank position sensor and double checked the timing marks on the cams to make sure it didn't skip a tooth. Still no start. Any more suggestions. PCM maybe?

does the tach meter move now with the crank sensor????

can you check for spark????

Customer: replied 3 years ago.

Tach is still dead. What's the best way to check for spark? I have a Sun induction timing light. Would that work?

I believe this is a coil over so remove one of the front coils, remove the plugs and plug it into the coil and crank the motor

Customer: replied 3 years ago.

Ok thanks, I'll check in the morning.

i will be around tomorrow

Customer: replied 3 years ago.

Did what you said; pulled a plug, put the coil back on and cranked the engine. No spark. I could smell fuel though so I think it's getting fuel.

yes, I agree.

do you have a code scanner to see if there are any codes???

Also, I am wondering about the timing belt., if it is turning.


Customer: replied 3 years ago.

I don't own a code scanner (yet). I have the timing belt covers off and checked the timing marks. They look fine. I haven't actually seen the belt turn when cranking, but everything turns fine when I used a wrench to manually turn the crankshaft.

ok, check all fuses with a test to verify power. did the check engine light work with the key in the on position??

Customer: replied 3 years ago.

The check engine light comes on with the key in 'on' position. I checked all the fuses for burn -out yesterday and found the fuse labeled B/UP LP TCU blown. I replaced the fuse today and it blew as soon as I cranked the engine. I did not think it was related to the starting problem. It was a 10amp but I was out of 10's and put in a 20. (I know, bad idea). The 20 hasn't blown yet. Don't know if this is relevent. I don't know what LP or TCU means.

tcu is the transmission control moduel.

remove the 20 amp fuse as you may do harness damage is you continue to use it. I would try to unplug the trans control module and see if the fuse blows again.

This needs to be checked out as it may be providing power to the engine pcm as well as the trans control module

Customer: replied 3 years ago.

Ok, will do. I'm finished for today because I have to go to work soon. Thanks so much for your help. I'll let you know what happens. I'm working long hours so I don't know when I'll get a chance to look at it.

ok, let me know

Customer: replied 3 years ago.

Hey Roy, just a follow up. Re the 2003 Santa Fe no start. So far I've changed:
crank position sensor
ignition coils
cam position sensor

Compression showed only 90psi in the cylinder I tested but my other
car, a hyundai elantra shows the same and it runs. It's an old
compression tester and may not be accurate. Also it was about 28
degrees F the day I checked.
I've opened the fuel tank, removed the pump and tested it (good).
Cleaned the filter. It didn't look bad. Voltage check shows fuel pump
is receiving no voltage when the key is on.
I've rechecked the fuses twice. No more blown. Pulled the fuel pump
relay and the ecu relays and they all check good. (I have a 12vdc
power supply). I checked the relay sockets and they are all getting
12v constant and 12v trigger when key is on. Checked the connector
plugs to the cam and crank sensors and they are both receiving
reference voltage when the key is on.
I charge the battery periodically so it doesn't run down.
I verified the cams timing one more time today. Spot on.
I bought a scanner/code checker but it shows no codes, only gives an
alert on the fuel system. I assume because the pump isn't running so
no pressure.

Only two components I haven't checked or replaced that have shown to
be possible problems for other people with the same problem: EGR and
MAF sensor.

Other than those two, I have to look to the pcm.

Do you have ANY insight on what could be the problem? I'm about ready
to junk the car except I have too much money tied up in new parts.

ok, lets back up and start with basics.

90 lbs of compression is low. the 3.5 has 4 cams??? did you look at all the marks on all the cams with it at tdc???

if you spray carb cleaner into the air filter, will it start and die???

did you check for spark while cranking???

is the check engine light on when the key is in the on position??sorry for the questions but lets review before proceeding to a bad pcm

Customer: replied 3 years ago.

I checked for spark previously and there was none.

The check engine light is on when the key is on.

Yes, there are four cams. And yes, all four marks line up correctly
when the crank is at TDC. I use a mirror to see both banks clearly.

I haven't tried spraying starting fluid into the air filter. I will
do this when I can and let you know.

Really, you've gone above and beyond for what I've paid. I don't
expect you to put in any more time and effort on this problem. thanks

ok, I see you did a crank sensor.

the other thing is this fuse that blows. what number is the fuse??

Customer: replied 3 years ago.

number 25 - backup lamps, vehicle speed sensor, TCM . It's a 10A.

ok, let me research the circuit and see if it has any connection

hello again, I posted twice after this looking for more info but I guess you did not get this.

did you spray carb cleaner into intake??

is the fuse panel you are using in the car or under the hood for the 10 a fuse??

Customer: replied 3 years ago.

I think I responded in the wrong box. But what I said was, I sprayed starting fluid into the intake and got no response. But I discovered today that the intake cam gear on the back bank is one tooth off. I had checked it a couple times already but it was tough to see straight on. Would that cause a no-start?

I checked for spark previously and there was none.

if there is no spark, then the cam being one tooth off will have no effect on this issue. it still must be corrected before you do valve damage

Customer: replied 3 years ago.

Tried starting fluid in the intake. Nothing. The fuse is no. 25 in the interior fuse box.


Rechecked the ecu relay today. Tests fine. The socket shows 12v on pin 30 and 12v also on the trigger pin (86). Even with the key out of the ignition. I can hear the relay click when I put it in the socket. Is this right?

Passenger Compartment Junction Block Layout
Passenger Compartment Junction Block Circuit Details
Engine Compartment Junction Block Layout
Engine Compartment Junction Block Circuit Details

if you see the fuse on this block also has a ignition failure sensor. I will check into that

Customer: replied 3 years ago.

You gave me the critical information I was missing. My fuse chart doesn't show the ignition failure sensor on fuse 25. So I did some more research on that and learned that a coil pack failure can burn out the IFS. Since I already installed three new coil packs, I just replaced the IFS, which is right on top and easy to get to. Lo and behold, the car runs again.


Now I'm getting a check engine light for O2 sensor and O2 sensor heater. I had them disconnected for a few days when I was troubleshooting. Plus the car sat for awhile, so I'm hoping the light goes away after a few drive cycles.


But the car runs and I'm happy. Thanks again for all your help.

good job. the light will go out after 50 key cycles with no issues. if it stays on then we will deal with it.