I have an unusual problem that stumps even my mechanic. My 2.4V Camry sometimes won't start after the engine is turned off within 10 minutes. The electrical power and radio and dashboard lights and engine fan turns, but it just won't ignite and crank. All I have to do is wait 10 mins without attempting to start the engine, then it will start and crank as usual. I've visited Toyota service center, relay has been changed, but it only solved the issue temporarily. Initially I suspected immobilizer issue, but when the turnkey is in the slot, the security lights didn't blink, meaning not immobiliser issue.
anyone has any idea what is the problem?

 

Are you stating the engine turns over but does not start?

You state the problem goes away if the engine is operated for over 10 minutes?

Did the shop check for ign spark and injector pulse?

 

You can only hear the whirring sound of the electric fan. The internal combustion engine does not start or crank. There is no engine ignition sound when starting. Electronics are all operating when the key is turned to ignition.

This problem only happens after engine turned off, and attempts to restart the engine is made less than 10 mins from the time engine is turned off. Sometimes it happens more frequently if the boot is opened and then closed or when AC was on before the last engine shut down, but not always.

The spark plugs have been changed and engine relay changed as well. Still problem persisted.

Sorry if I wasn't clear about the earlier post

 

The anti-theft system does not prevent the engine from cranking over, the engine will just not start.

When the ign key is turned to Start a small relay is energized. This relay then sends +12V power to the large relay built into the starter solenoid. From your statement the dealer may have replaced the small relay. Do you have the repair record or old part?

One should be able to diagnose the situation. When the ign key is turned to start there should be +12V at the SMALL wire going to starter solenoid (black/red). One can also bypass the starter system wiring/relay by applying +12V directly to this SMALL wire which should result in the starter motor/engine turning over.

Note the LARGE wiring going to the starter solenoid is constant +12v directly from the battery. Has happened this cable deteriorates, has a bad end terminal, etc. Here if suspected one can bypass the cable using a battery jumper cable.

When the starter does not engage, one might try hitting the body with a soft end hammer. Yes, this can work.

 

Today it happened again. This is the video link from Google drive of what was happening. Again wait for 10 mins, car starts as usual again.



https://drive.google.com/file/d/14Pz...w?usp=drivesdk

 

What's the flashing light on the instrument panel in the upper left hand corner?

 

Oh that's just the seatbelt sign. But the car starts without seatbelt worn anyway. One Mechanic suggested for the immobilizer to be bypassed by opening the dashboard.

 

Don't think the immobilizer can be disabled even if one tried.

There has to be security light somewhere to note if it is still on. Download the owners manual at the link below and find said light:

https://www.toyota.com/owners/resour...owners-manuals

Typically when using a key (as in not having push button start with a Smart Key FOB), when turned to start the engine should turn over. The security system keeps the engine from starting not turning over.

My opinion is there is something going on that prevents the starter system from engaging as in something is wrong.

The starter system has electrical switches that only allow the starter to work when the trans in in Park or Neutral. The next time this no start issue happens try N, as the P switch may be bad.

Does the car have an aftermarket security system?

 

No the position in P or N won't start as well. Also there is no aftermarket security system.

 

Could be a bad starter solenoid. If you a have volt meter one can check for +12V at the small black wire going to the solenoid when the ign key is turned to start. If power then the circuit to the solenoid is OK.

If power at the wire one apply +12V at the connector to the black and determine if the starter engages.