1999 C5 shutdown
11-01-2006, 08:50 PM
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1999 C5 shutdown I am tuning a 1999 C5 automatic and when i get on it even just a little bit (about 18% tps), the car goes into some failsafe mode and says performance reduced and starts to run like ****. Normal driving it runs fine, but when i get on it at all, this happens.
This seems to have happened after modifying the VE tables a lot. LTFT's were 25+ so after adding 25+ to the VE tables and smoothing and retuning a couple times, the LTFT's are now between -5 and 2, normally right around 0.
The only thing I can think of is that it is comparing the MAF table to the VE table and sensing that they are so different that it is shutting the car down. Any ideas? Am I right? Am I wrong?
The only code i am getting is P1514 which doesnt seem to be relevant.
This seems to have happened after modifying the VE tables a lot. LTFT's were 25+ so after adding 25+ to the VE tables and smoothing and retuning a couple times, the LTFT's are now between -5 and 2, normally right around 0.
The only thing I can think of is that it is comparing the MAF table to the VE table and sensing that they are so different that it is shutting the car down. Any ideas? Am I right? Am I wrong?
The only code i am getting is P1514 which doesnt seem to be relevant.
11-01-2006, 08:53 PM
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MAF Rationality Test Failure. You'll have to adjust the table under the Engine Diagnostic section. My table is increased 50% to avoid this DTC.
**EDIT** See post #6.
**EDIT** See post #6.
Last edited by SSpdDmon; 11-01-2006 at 10:36 PM.
11-01-2006, 09:23 PM
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Originally Posted by SSkeet
I am tuning a 1999 C5 automatic and when i get on it even just a little bit (about 18% tps), the car goes into some failsafe mode and says performance reduced and starts to run like ****. Normal driving it runs fine, but when i get on it at all, this happens.
This seems to have happened after modifying the VE tables a lot. LTFT's were 25+ so after adding 25+ to the VE tables and smoothing and retuning a couple times, the LTFT's are now between -5 and 2, normally right around 0.
The only thing I can think of is that it is comparing the MAF table to the VE table and sensing that they are so different that it is shutting the car down. Any ideas? Am I right? Am I wrong?
The only code i am getting is P1514 which doesnt seem to be relevant.
This seems to have happened after modifying the VE tables a lot. LTFT's were 25+ so after adding 25+ to the VE tables and smoothing and retuning a couple times, the LTFT's are now between -5 and 2, normally right around 0.
The only thing I can think of is that it is comparing the MAF table to the VE table and sensing that they are so different that it is shutting the car down. Any ideas? Am I right? Am I wrong?
The only code i am getting is P1514 which doesnt seem to be relevant.
11-01-2006, 09:30 PM
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I went to Power reduction based on the EFI Live VE tutorial, this table was sent to me and solved the issue, it was sent to me by dfe1 from the EFI Live message boards. Thanks it worked for me 
Beer
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11-02-2006, 08:29 AM
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Actually I figured it out on the HPTUNERS forum...it is the P1514 diag code.
It measures Calculated Airflow. vs TPS. vs RPM. and if the values are greater than the ones in this table then it shuts the car down lol. So I have to raise these values just slightly (+ a few to be safe) over the dynamic g/cyl reading from the maf.
It measures Calculated Airflow. vs TPS. vs RPM. and if the values are greater than the ones in this table then it shuts the car down lol. So I have to raise these values just slightly (+ a few to be safe) over the dynamic g/cyl reading from the maf.
