2002 4.3 GXI-B Audible Alarm & Protection Mode

[DouglasW]

It should be right if the voltage to the injectors is not too low. I would check the 12v from the high end of an injector to ground. It should be very close to the battery voltage. I think the DTC is saying the voltage is too low at the driven end of the injector and that could be true if the incoming voltage is too low.

I should mention that I was going on information that might be inaccurate. The cross reference file could be in error since it was written by a normal ADX file user and not necessarily a professional. But since everything seem to correlate (active and logged DTC's agree and it does show that the trouble lamp is lit), the data is likely accurate.

 

[jake7995]

The voltage tested the same as battery voltage. You lost me with the file and inaccurate information. Do you mean the info in the software might not be accurate?

 

[DouglasW]

It might not be as it is a beta version with little testing so far. I am 95% sure it is telling you the right codes, but can't be 100%.

Part of the problem is that code 81 is a catch-all for Mercruiser/Volvo and can mean many things. You can test the code easily using a CodeMate or just a light bulb and shorting two pins on the connector, but it would just say "81" and that doesn't narrow it down much.

 

[jake7995]

I paid a local shop to pull codes for me a few weeks ago and they came up with the same codes so it is accurate.

 

[DouglasW]

Thanks for the feedback. I will make a note of that verification.

 

[DouglasW]

Disregard the following. That looks like a bug in the software, will fix it.

I just noticed something that may be of interest. The throttle sensor volts show up as .00 volts with ignition on and engine off. That should be about 0.7 volts normally when the engine is off and the throttle is at minimum. I would run the scan again while you move the throttle up and down. It should vary from about 0.7v at idle position to around 4.5v at WOT. Also run a new scan wit the engine idling.

 

[DouglasW]

Here is the link to the fixed version: http://www.mediafire.com/file/w7tha9892wz83ev/MEFI4_beta20.zip/file

 

[QBhoy]

Hi
I have the mercruiser variant. I can tell you that one simple fault (one of the well known MPI and GXI faults) can send everything haywire. You can and I did drive myself nuts chasing faults shown on the smartcraft. Things like injector faults, misfire on cyl 6,5,4,8 etc etc can all be caused by other fundamental faults like
throttle position sensor.
Sw pressure sensor
iAC
the battery. Despite being able to turn the engine over and start it....can almost unbelievably cause faults if it’s anything other than tip top
but....the one big one...the diz cap. Change it out and see how she goes. If it doesn’t solve your issues,it won’t be a wasted effort. It will fail at somepoint soon.

 

[jake7995]

Douglas, what was the flaw in the system? I did watch the position sensor to make sure it was seeing 100 percent throttle to clear the codes. It did go to 100 percent. I changed the distributor cap already. It is winterized now so all of my testing will be with the engine off until spring.

 

[DouglasW]

The app was referencing the wrong parameter. It was still for the TPS but the wrong one. The fix was simple: Change "0x2E" to "0x2D". The app should have never reported the TPS voltage as zero if it was working at all. The reading for the TPS percentage was correct.

 

[Jesper]

Hi im having same problem, with audio alarm as soon as key is turn to on, seems to be same problem as you, what was the problem?
b.rgds Jesper from greenland