2003 Camry 4 cyl 2AZ-FE Trouble Codes Primary Secondary Circuit.
 

New to the forum here. Thanks in advance for your help.

2003 4 cyl Camry LE 5M

ck engine code (DTC) PO 351, 353, & 354, but not 352. ? Primary Secondary circuit.

Runs fine until reaching operating temperature and cruise RPM.

Then misses and Quits. Cools down, runs OK again.
Compression good 194 per cyl.
Coils and plugs must be good or the engine wouldn't run OK when its cold?

Bad gas? No, or it wouldn't run well cold.
Bad plugs? No.

How do you check the ECM pulse?
Could be either the IGT and the IGF or both.

Don't have an oscilloscope.

Do have a meter with Hz.

I'll assume the Cam sensor and the Crank sensor are good, if they weren't the engine wouldn't run.

Vacuum Leak? Can't hear one or find one.

Have you heard about the issue with the intake manifold on these 2002 & 2003 Camry 4 cyls ? A baffle inside the intake manifold comes loose and vibrates and rattles.
My mechanic friend Paul said it makes noise but won't hurt anything.

Toyota wouldn't fix it, even though it was a glaring factory defect. There was a bulletin, at about $800 plus. So I left it alone, and put up with the noise. You could only hear it at Idle. It was definitely noticeable. No way you could sell the car like that. The part was about $350 and two days of driveway labor. It's a real pain to get to.

But, the car runs good until it gets to operating temp and 2500 to 3000 RPM, +/-.

I'm stumped.

Thanks for any help.
Bud Hall

Insert See 3 posts down for additional information from Me, Bud

The ignition coil/igniter is connected to the ECU. The ECU sends out an IGT signal to the coil stating to fire the plug. The coil sends back an IGF signal that the plug was fired. The computer looks for the IGF signal and if not present trips one of the codes you list. A different code per coil.

Each coil IGT wire is connected to the computer allowing individual operation. The wiring for the IGF output of each coil is ganged with the other coils IGF output. Thus the computer is going receive 4 IGF pulses for every one IGT pulse it sends out.

Toyota uses the oscilloscope function of their diagnostic tool to view the IGT and IGF waveforms.

At engine idle the IGF signal is 4.5-5.5 volts. If there is enough signal generated during cranking (engine no longer runs) to check the IGF signal don't know. Perhaps a volt meter could indicate a response when the engine is cranking during starting.

Suppose one may be able to check the signal frequency of the IGF wire of each coil identified by a trouble code and compare to coil that isn't generating a code. But IGF coil wire would need to be isolated.

Since issue seems to only occur when engine is hot then heat may be a problem (obviously).

Suggest checking the wiring IGF wiring (white/red) and connections which are ganged. The +B (12v power) wiring (brown/orange) (ganged) including the noise filter (capacitor) attached to the wiring and the coil ground wiring (white/black) (ganged). Plus the plug-in connection at the ECU.

Might pickup a few cans of freeze spray which is liquid in spray can that when sprayed onto items causes their temperature to drop. Then when the engine stops running spray the coils until they are cold.

The coils are known for failing and some owners just replace all of them at once. Given your symptoms and 3 coil trouble codes it may be a wiring/connection issue.

Thanks always appreciate the help. Dealer 101 is to replace all coils 1st or so I've read.
Could bad fuel produce these codes?
I've also read dirty throttle body, vacuum leak are frequent causes, but again engine runs fine until it heats up and 2500 to 3000 RPM at cruising speed.
I'll try to figure out how to test the IGT & IGF signals with a meter.
Your info is helpful.

New Developement now 9 DTC'S
 

Drove the car up to get high test gas started missing and quit on the way back. Picked it up later took about 7 or 8 15 to 20 second cranking cycles and then started, drove it home about half a mile.
Now it has 9 codes, all 4 coils PO 351 thru 354, PO 300 thru 304 and a random misfire code.

Mechanic wants to change all the coils.

If one coil isn't sending back an IGF code will that shut down the engine?
Acts like a fuel pump issue but I've been assured they very rarely go out.

No cam sensor or crank sensor codes.
Coils fire. Plugs good.
MAF sensor? Temp sensor?

Ever heard of a Fotga Techstream Computer diagnostic software and cable?

What are the odds of all 4 coils going out simultaneously?

The injectors have to work or the engine wouldn't run well cold.

It would miss, sputter, and shake.

Cleaned throttle body intake and checked for vacuum leaks. Cant hear any but don't have smoke.

What now?

Thanks, Bud