need code help
04-18-2009, 11:52 AM
#1
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need code help I recently installed a P1SC1 supercharger on my H/C car. I have a FAST intake with LS2 TB (may be relevant)
I took the car to get tuned/dyno'd a couple weeks ago, and after a couple of simi-aborted runs , we found I did not have enough fuel pressure (pressure dropping to mid 40s) to continue the tune.
Although we didn't get a chance to tune the car, there was no question it was pulling hard on the dyno until we would shut down each time. (no running problems)
On the way home, I eased hard into the throttle and it "spit/popped" and went into reduced power mode. cleared the code and came on home.
After removeing the fuel pump (and damaging the sending unit which I had to replace) I buttoned everything back up, and went for a test run.
EVERY TIME I roll hard into the throttle to go WOT (probably at the point it is just about to go into boost) it sound like it "pops" back (not loud) through intake and it goes into reduced power.
It gives me a PCM - P1514 (throttle body performance) and TCS - C1278. I clear the codes and it runs, but not sure what it means. It ran strong on the dyno with three WOT runs, so what is going on?
Thanks for the help
I took the car to get tuned/dyno'd a couple weeks ago, and after a couple of simi-aborted runs , we found I did not have enough fuel pressure (pressure dropping to mid 40s) to continue the tune.
Although we didn't get a chance to tune the car, there was no question it was pulling hard on the dyno until we would shut down each time. (no running problems)
On the way home, I eased hard into the throttle and it "spit/popped" and went into reduced power mode. cleared the code and came on home.
After removeing the fuel pump (and damaging the sending unit which I had to replace) I buttoned everything back up, and went for a test run.
EVERY TIME I roll hard into the throttle to go WOT (probably at the point it is just about to go into boost) it sound like it "pops" back (not loud) through intake and it goes into reduced power.
It gives me a PCM - P1514 (throttle body performance) and TCS - C1278. I clear the codes and it runs, but not sure what it means. It ran strong on the dyno with three WOT runs, so what is going on?
Thanks for the help
04-18-2009, 12:37 PM
#2
Most likely the 1514 predicted airflow tables need to be set properly in the tune.
This is a common error when tuning because a vette won't throw the code on the dyno.
The car, when this is overlooked, usually throw the code and enter reduced power mode just as the car gets into boost, or if you at elevated rpm and stab the throttle.
This is a common error when tuning because a vette won't throw the code on the dyno.
The car, when this is overlooked, usually throw the code and enter reduced power mode just as the car gets into boost, or if you at elevated rpm and stab the throttle.
04-18-2009, 08:26 PM
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SOUNDS LIKE NoGo HIT THE NAIL ON THE HEAD.
c1278= TCS temporarily inhibited by pcm.
Pcm monitors various parameters. Pcm will not allow traction control operation if nay parameter fall below a predetermined value.
sounds like this code is a result of the P1514
P1514=tac system maf problem.
Pcm uses throttle position sensor (tp), barometric presure (baro) sensor, intake air temperature (iat) sensor and engine rpm inputs to calculate and expected mass airlow (maf) value. Pcm compares this value to maf value and a speed density calculation to verify proper throttle operation.
dtc will set when following conditions are met:
...
...
...
pcm detects actual maf value and speed density much greater than expected airfllow rate.
c1278= TCS temporarily inhibited by pcm.
Pcm monitors various parameters. Pcm will not allow traction control operation if nay parameter fall below a predetermined value.
sounds like this code is a result of the P1514
P1514=tac system maf problem.
Pcm uses throttle position sensor (tp), barometric presure (baro) sensor, intake air temperature (iat) sensor and engine rpm inputs to calculate and expected mass airlow (maf) value. Pcm compares this value to maf value and a speed density calculation to verify proper throttle operation.
dtc will set when following conditions are met:
...
...
...
pcm detects actual maf value and speed density much greater than expected airfllow rate.
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04-23-2009, 07:28 AM
#8
If I remember correctly. On HP tuners there is a 1514 table in the Engine Diagnostics section.
If you want to keep the code functional, but just get rid of it, then a good rule of thumb is to bump the table up the same ratio that your torque has shifted.
If you just want the problem to go away, then set the entire table to its maximum value.
If you want to keep the code functional, but just get rid of it, then a good rule of thumb is to bump the table up the same ratio that your torque has shifted.
If you just want the problem to go away, then set the entire table to its maximum value.
