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Skyvisions, ASE Certified Technician
Category: Toyota
Satisfied Customers: 14417
Experience:  Toyota Master Diagnostic
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Toyota Sienna LE: I have a customers 2003 toyota sienna. Owner

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I have a customers 2003 toyota sienna. Owner was on the way to work and stopped for food. Came out of the store car cranks over but will not start. There is fuel and the injectors are pulsing. There is no spark however. Scanner shows no codes. Changed crank sensor with new unit no change. Right now I am at a loss. Any ideas?
Hello, thanks for trusting me to help you with your vehicle today. I have over 30 years of Diagnostic experience. I look forward to working with you. When you turn the key to the on position does the check engine light illuminate? Do you have 12 volts to the ignition coils with the keys on?
Customer: replied 3 years ago.

yes there is voltage to the coils


when the key is in the on position does the check engine light come on?
Customer: replied 3 years ago.

yes it does come on

Customer: replied 3 years ago.

I also did replace the crank sensor it made no change

when you hook your code reader to the vehicle connector does it say whether it is communicating or does it say there are no codes.
Customer: replied 3 years ago.

It is communicating. I had introduced a vac leak code and was able to erase it. I can also see the engine cranking at around 200 RPMS. There were no codes however when I first started.

we are running out of options here the next step is going to be using a voltmeter to test different control components. Is this something you will be able to do?
Customer: replied 3 years ago.

yes I am able to do this and I have printouts of most of the components. I have alldata. I did note while looking at alldata that there is an immobilizer system in these cars. do they all have it and could this be an issue?


this was actually was going to be my next question. Do you have the vehicle identification number and if it does when you stick key in the ignition does the security light stop blinking or is it still blinking?
Customer: replied 3 years ago.



The security light is out completely.


just to clarify you're saying that when you remove the ignition key from the lock cylinder the little red security light does not flash at all?
Customer: replied 3 years ago.

no flashes at all the light is totally out at all times



This is why the car is not starting. The immobilizer is shutting down the spark. Does the customer have any other ignition key?
Customer: replied 3 years ago.

Yes I am having them bring me the original key this one is a copy and it was made not too long ago. How does the car sense the Key? I know like the Gm's had a resistor.


When you insert the key into the ignition lock cylinder a switch is turned on and the transponder coil that is around the ignition lock cylinder excites the chip in the key and this sends a signal to the transponder ECU and then that tells the computer that the system is ready to be turned on. If this signal is not received in the engine control computer from the transponder coil it will not fire the ignition you will have injector pulse no ignition. This fits the description exactly.
Customer: replied 3 years ago.

I am not sure if you got my last reply? I tried another key no change still no light. Is there any way to bypass the immobilizer so these people have a car the entire family is stranded and cannot get to work and school. I am really under a gun here! Thanks for yout help!!


there is no way to bypass this is the computer does not see the signal from the transponder it will not start. Unfortunately I have very bad internet I am on the road. I will do some research on the transponder system and see if there's a possible power supply problem.even if you have a bad or wrong key security light should still flash.
after looking at the wiring diagram there is no independent power supply to the transponder unit. The code is sent from the transponder unit right to the engine control computer. Can you post a picture of the security light that is not on? Did you remove the plastic all cover from around the switch to see if anything is misplaced or unplugged for the transponder by the key
Customer: replied 3 years ago.

I have a photo in my phone where can I send it to you?

the key switch is in the dash on the car I have pulled the lower panel off but I do not see anything


there should be a toolbar on your end that will allow you to attach photographs.
Customer: replied 3 years ago.

that is the older system. Let me do some research at my next stop for I have better internet and I will get back to you. Sorry this is taking so long but this is a complicated situation in this type of format.
Customer: replied 3 years ago.

thanks for all your help! I'll be here until 8pm

According to the vehicle identification number and that illustration of the security light this has been VIP 3200+ system. This should not have the immobilizer system. I need you to confirm that by looking at the ignition key and measure the thickness of the plastic head portion of the key. Then look at the steel shank of the key just down from the edge of the plastic head is there a steel impression or a dimple like someone punched it with a center punch? Did the customer have any steel key that ever started the vehicle with no plastic head?
Customer: replied 3 years ago.

OK Now this brings up some more questions!

The keys have no dimples! the original key measures .288 or 9/32".

The newer key measures .273 or 9/32".

My next question is one I have been pondering all day! The engine seems to turn over very fast. I ran a compression check on the middle front cyl. and got 75PSI. If the timing belt jumped a few teeth would I and /or could I lose the spark. The plug was wet with gas.

It was also another reason I wanted to bypass any shutdown system. The alarm system in the car locks the doors and flashes the lights beeps the horn and can open the side door. So where do I go from here!



I think we are now onto something. 75 PSI is not enough. This sounds like the timing belt has jumped time. If it jumps to far the cam sensor in the crank sensor will not be in the right correlation and you will not get spark. Pull the upper cover and check the timing belt and make sure it is in time. It is unlikely that it is given the number on the compression. If necessary replace it and see if it will start. It sounds like we have got situation resolved I don't believe this is and immobilizer issue after all once we have confirm that with the key and with the picture. The vehicle identification number does not come up with immobilizer either. The remotes sound like you're working normally. Let me know what you find with the timing belt I will be off-line later.
Customer: replied 3 years ago.

I will check the timing belt tomorrow I have gone home for the evening! Thanks for all your help!


Customer: replied 3 years ago.

I just talked to the owner for a bit. Interestingly I had forgotten I had done a timing belt with tensioner about a year ago. The customer said he came out from WAWA after getting his dinner he is the police dispatcher in our town and works the night shift. When he went to start the car it started and ran for a minute then the tach dropped to 0 and the engine stalled out. Each time he tried to restart it it would start and run as long as he kept the engine speed up to 2000 - 3000 RPM. Every time he tried to bring it to idle it would stall out. He tried it several times while trying to move the car but it finally stalled out and he gave up. Now I at a total loss. Any ideas?

Thanks for your time!


Based on the latest description that also fits a bad timing belt or jumped timing belt. You need to rule this out before we go any further. Let me know.
Customer: replied 3 years ago.

OK! Interesting developments! I went home last night and called the customer! This time however I finally got a hold of the husband. I had him explain to me in exacting detail exactly what happened!This morning I came in and started the car with my foot to the floor and the car starts. In fact as long as I work the gas pedal I can get it to idle all the way down to 500-600 rpm. pulled a vacuum line of and the car stayed running. I am thinking I have a stuck IAC??? Your thoughts?

A sticking idle air control valve will in some cases cause it to be difficult the start initially until the throttle is cracked all the way open. It won't idle without feathering the throttle this is a good place to start. However this does not explain the 75 pounds of compression that you said that you had.
Skyvisions and 4 other Toyota Specialists are ready to help you
Customer: replied 3 years ago.

Well "We came" "We Saw'' and "WE KICKED IT'S @$$!!!!!!!!!!!!!!!!!!

Installed one new IAC and problems all solved! Still do not understand the no spark. However the low compression is gone I imagine it was a gas wash of the cylinders from both the owner and myself cranking so much until I disabled the fuel pump to stop that. Thank you for all your help! Some times ya just have to put a few heads together! The final key point of information came from the owner who stated the car would run if you held the gas pedal down while cranking! Have a great weekend you were a great help! I was very satisfied with your help and your willingness to go even after hours trying to figure this tough one out!

Thank you, and you're welcome. Sometimes it just takes going to all the possible variables to get to a complete solution. If you need anything in the future make sure you ask for me Skyvisions, in the question and I will get back to you.
Customer: replied 3 years ago.

Thank you very much! I have already rated you! I gave you the highest rating! You very much deserve it!

Have a great weekend!


You are welcome. Have a great weekend. I have to reply to you no need to reply back if I don't reply it locks me out of other questions.