2001 Camry - Misfire code = new ecu ?

[Max_Wander]

Originally Posted By: youdontwannaknow

Friend's 2001 Camry 4-cyl started hesitating while driving and then just stalled and won't start. CEL is ON and DTC P0300 (random misfire) is set. Car was towed to dealer. Dealer says will need to replace ECU, all 4 injectors and plugs. Bill = $3500.


Sounds like they're trying to rip your buddy off big time. ECU's rarely go bad, especially Denso units, but regardles they probably want to charge you to change it, and NOT change it. Who'd be the wiser?

Quote:

Does that make any sense to you ? Is this possible ?


No sense, highly unlikely. As said, it sounds like a possible vacuum leak or just worn ignition components. UNLIKELY it's the Injectors........ go to another shop! These guys seem like they just want to 'replace' a bunch of parts and cross their fingers that it solves the problem, as usual.

 

[FowVay]

I'm going to take the otherside of the argument here. I don't believe they're trying to rip your friend off. The dealership is simply complying with a service bulletin that Toyota has implemented to address this exact problem.

Toyota Service Bulletin EG004-03 states to remove and inspect the injectors and replace them if they are discolored. The bulletin also states to replace the ECU with a updated software version and to check a clearance on the throttle body and make the dimensional adjustment if necessary.

Finally they add a can of fuel injector cleaner and state to inform the owner to use a name brand fuel with minimum octane of 87.

Here are the updated part numbers for the repair:

ECM w/o immobilizer and with automatic trans: 89666-06121
ECM w/o immobilizer and with manual transmis: 89666-06111
ECM with immobilizer and with automatic tran: 89666-06131

injector set: 23209-03010

injector cleaner: 08813-00080

Toyota mentions their 96 month/80,000 mile warranty to be used to cover the ECM repair. Since your friend's car is only slightly out of this warranty period I'd ask the dealership to try to do a goodwill warranty repair since it is a known problem.
Replacing the injectors and plugs is only done if discoloration is noticed and not necessarily required.

 

[brianl703]

Let me get this straight. The ECU needs a software update and the only way to implement this is a whole new ECU?

There's this wonderful thing called "flash memory". It's been around for a long time and most of Toyota's competition has been using it for over 10 years now. This wonderful innovation eliminates the need to replace the ECU when a software update is required.

I'm trying to figure out what the heck a clearance on the throttle body has to do with the ECU and the fuel injectors.

What is the real root cause of this problem?

The injectors?
The ECU?
The throttle body?

Quote:
state to inform the owner to use a name brand fuel with minimum octane of 87


Then to top it off they suggest that the owner used poor quality fuel and that somehow [censored] up their ECU, injectors, and throttle body.

Quote:
Toyota mentions their 96 month/80,000 mile warranty to be used to cover the ECM repair.


That would be the Federally-mandated 8 year, 80,000 mile emissions warranty.

 

[brianl703]

I found the TSB and it would appear that the root cause of the problem is a mis-adjustment of the vacuum-controlled throttle (I thought it was drive-by-wire but the TSB also mentions a throttle cable...is Toyota using a vacuum actuator to control the idle?) which apparently causes the engine to run rich (the TSB mentions to check for carbon-fouled spark plugs).

I expect the replacement ECU contains new programming that won't allow a misadjusted vacuum-controlled throttle to cause the engine to run rich.

Here's the TSB:

http://toyota.justanswer.com/uploads/skyvisions/2008-05-29_155212_01_camry_p0300.pdf

It also has this gem in it:

Quote:
Attempting to start the vehicle with the accelerator pedal depressed can lead to
some amount of misfire and possibly contribute to causing a M.I.L. “ON” condition.


Incidentally, for years, on most fuel injected vehicles, starting with the accelerator pedal depressed puts the computer into clear-flood mode so it turns off the injectors.

 

[FowVay]

brianl, your assessment would be correct. Carbon buildup is a symptom and is the cause of the misfire and is what needed to be corrected. The bulletin also says to drive the vehicle at 60 mph for at least 30 minutes to facilitate removal of carbon.

But back to the original posters issue: I'd try to get the ECU warrantied under the emissions warranty. The other items, if required, won't be covered.

 

[MrCritical]

I hate to tell you but you can't goodwill emissions warranty. Not by one mile, or one day.

It is what it is, and no more.

 

[brianl703]

This is just an all-around poor design. A misadjusted throttle should not ever cause the engine to run rich.

 

[youdontwannaknow]

what's really odd about that TSB and the dealer's talk is that there is nothing anywhere that 'rules out' the possibility of a bad ecu. And there is nothing that 'rules in' the possibility of a bad ecu either. No tests or checks for the ecu ??

just replace the darn thing ??

Can't believe that coming from Toyota!

 

[brianl703]

I'm guessing that they know the programming in the ECU is faulty.

Why they would design an ECU in 2001 that couldn't be flashed with new firmware to solve the problem...is another question.

Yet another question I have is why this isn't an emissions recall. If the plugs are carboned up this engine is not running clean.

 

[javacontour]

Not the case for Toyota, at least not my Geo Prizm (with the Toyota ECU and 4A-FE engine.)

My first oil change, I tried this, and it started at WOT. (Note to self. try these things on a warm engine BEFORE you change the oil. However, it hasn't seemed to damage the car as I've owned it for 5 years and 125K miles since then.)

So while many cars do have this feature to clear a flooded engine, not all do.

Originally Posted By: brianl703
I found the TSB and it would appear that the root cause of the problem is a mis-adjustment of the vacuum-controlled throttle (I thought it was drive-by-wire but the TSB also mentions a throttle cable...is Toyota using a vacuum actuator to control the idle?) which apparently causes the engine to run rich (the TSB mentions to check for carbon-fouled spark plugs).

I expect the replacement ECU contains new programming that won't allow a misadjusted vacuum-controlled throttle to cause the engine to run rich.

Here's the TSB:

http://toyota.justanswer.com/uploads/skyvisions/2008-05-29_155212_01_camry_p0300.pdf

It also has this gem in it:

Quote:
Attempting to start the vehicle with the accelerator pedal depressed can lead to
some amount of misfire and possibly contribute to causing a M.I.L. “ON” condition.


Incidentally, for years, on most fuel injected vehicles, starting with the accelerator pedal depressed puts the computer into clear-flood mode so it turns off the injectors.

 

[youdontwannaknow]

Originally Posted By: brianl703
I'm guessing that they know the programming in the ECU is faulty.

Why they would design an ECU in 2001 that couldn't be flashed with new firmware to solve the problem...is another question.

Yet another question I have is why this isn't an emissions recall. If the plugs are carboned up this engine is not running clean.




It SHOULD be a RECALL, and not just stupid TSB, especially when it involves a stall condition during operation. Imagine you are on the highway and it just sputters and cuts off or in the middle of nowhere. Actually it did happen on the freeway.

 

[brianl703]

Originally Posted By: javacontour
Not the case for Toyota, at least not my Geo Prizm (with the Toyota ECU and 4A-FE engine.)


Yep, Toyota appears to be one of the few exceptions to the rule.

Wonder if Bosch has a patent on clear-flood mode they didn't want to pay for