So here's my problem

Reset ECU....throttle works for about 6-8 seconds..car throws a solid CEL...and throttle is limited to maybe 5% opening. There is no code for the CEL( that my scanner can see anyway), and when the PCM is reset the throttle works as above again. If I try to restart without a clear the throttle is limited as above

I've checked the wiring harness for the throttle, tried a new throttle body, tested the harness to the MAF, TB, MOP....fuses and relays are all good....tested the harness to the relays.

I'm almost ready to put a frag grenade under the hood and pull the pin

Any ideas what can cause an instant CEL and limp mode?? I think it might be the MOP....but the current one tests OK

 

The FSM says that DBW fail-safe is cause by an improper APP sensor output (as I mentioned to you in the PM). The TP sensor can do it too, but you said you swapped the TB already (though that does NOT eliminate the harness).

 

Checked the harness..it's OK..I'm checking the APP sensor voltages now....let you know if that seems OK

Strange thing is the car did this a year ago..and the MOP was the problem

No Cel thing is a bit strange...

 

Well, there are two APP outputs and the behavior you are witnessing my be just a glitch in the output of one.

 

So you actually got your car started then Dan? :D

 

APP sensors tested OK
Scoped the Throttle control tested OK

 

They both tested perfectly normal

 

Starts..idles great....no throttle

 

Totally stinks.

Good to hear the idle is smooth, though

 

Yup..that means that when I figure this throttle thing out the rest is working properly

STINKS bad right now though

 

Do you have a list of all the codes that will throw it into limp mode ?

 

Nope....Problem is there is no codes set ( with the Scanalyzer anyway) I have a Service manual and didn't see that list??

I thought that MOP, ECT and DBW problems were the only ones that caused limp mode...and none of those codes are coming up...and everything I can think of scopes/checks out

 

I have never seen a list - just thought it would help you eliminate the possibilities if you had that info .... Perhaps Mazda could help with that ???

You have more than one version of scanalyser don't you ? Try the USB version if you haven't already ...

 

Suppose...problem is I find them less than helpful usually. Maybe if I could talk to a high level tech guy I could get some answers. The usual run of the mill techs have a difficult time with even the service manual stuff ( no slight to anyone who is a tech on here...nothing personal..just my experience with Mazda Canada)

 

PM that guy 'tecknics' I think his name is - he is a Mazda tech & seems to have quite a bit of knowledge ...

 

YA. Kevin definitely has a clue.....maybe he can ask around to the tech line as well

 

Still looking for ideas

 

wow,

dan send me an email. i will ask the question to the two master techs i know on monday.

but something on the inside of the passenger compartment? connections to the pedal itself? i saw a note on a failed acc pedal assembly recently. but odd, way odd..

beers

 

The APP sensors seem to be perfect?

Ask them what can cause throttle failure in 6-8 seconds..

 

Afternoon.....

 

phone call is in.

beers

 

^ Thanks man....

 

dan- no throttle at all or partial up to a certain rpm?

 

nm re-read first post.

what about fried o2 sensor? could possibly make the pcm think its in an overtemp situation so it limits throttle.

orrrrrrr........ what about weird signal from eshaft sensor? thinks its running high rpm sitting still- triggers low throttle.......

 

I've got a dealer mechanic ( one of the good ones ) coming over Tuesday night with the OEM Scanner......maybe there is a code that isn't showing up in the Hymsters Scanner

It's really a PIA...if I could get a throttle response..I could tune it and make it to the track day on the 29th in my car