LQ9 Throttle Blade not opening fully DBW more info

[VF1000R]

Ive gone through other posts having somewhat similar issues and not found an answer to my issue. So I decided to do some hard number measurements.

Throttle body connector values. 8 Pin , volts


Terminal Key on Idle (engine off) Key on Throttle Full (engine off)

A 1.6 11.56
B 0.4 0.33
C 1.6 10.31
D 0.3 0.39
E 4.27 4.3
F 1.0 2.00
G 1.1 2.38
H 4.9 4.9


To me the issue is clear, F & G are not getting full voltage. Those are the TP Sensors.

Rehashing. The swap was from a 2004 Escalade into a 96 Impala. Full Pull , ECM, Pedal and TAC, that started out OK, 400 Hp at RW.
Driveability issues at low speed , the Tuner made several adjustments. Some Improvement. Thats when I noticed the issue with throttle not opening fully.

I replaced pedal sensor, TAC, and swapped TB. No Change.

Now I ran across a post where a tuner used a 2005 Tune in a older ECM. Im assuming my ecm is E40 ? and had similar issues.

What do i need to do to figure this out ?

No Codes are showing except MIL, supposedly turned off as no lamp is lit.

[VF1000R]

Any help ?

[BrianPeppers]

2004 should just be a P59 PCM. They can run any gen3 DBW OS from 2003-2007.

[VF1000R]

[QUOTE=VF1000R;583121]Ive gone through other posts having somewhat similar issues and not found an answer to my issue. So I decided to do some hard number measurements.

Throttle body connector values. 8 Pin , volts


Terminal Key on Idle (engine off) Key on Throttle Full (engine off)

A 1.6 11.56
B 0.4 0.33
C 1.6 10.31
D 0.3 0.39
E 4.27 4.3
F 1.0 2.00
G 1.1 2.38
H 4.9 4.9


To me the issue is clear, F & G are not getting full voltage. Those are the TP Sensors.

Is there Anything in the Tune that could cause the TP sensors to act like this ?

My information is that 1 sensor is supposed to be opposite voltage of the other. And both supposed to cross each other as throttle is advanced.


IF im in the wrong section , please say so.

[blindsquirrel]

And what is the "full voltage" supposed to be? Because it's not specified anywhere in the service manual. Just curious how you know it's not what it should be.

[blindsquirrel]

2004 Escalade, yes?

Throttle Body Assembly

The throttle body assembly consists of the throttle body, the throttle position (TP) sensors, and the throttle actuator motor. The throttle body functions similar to a conventional throttle body with the following exceptions:
? An electric motor opens and closes the throttle valve.
? The throttle blade is spring loaded in both directions and the default position is slightly open.
? There are 2 individual TP sensors within the throttle body assembly.

The TP sensors 1 and 2 are potentiometer type sensors, each with the following circuits:
? A 5-volt reference circuit
? A low reference circuit
? A signal circuit

The TP sensors are used to determine the throttle plate angle. The control module provides each TP sensor a 5-volt reference circuit and a low reference circuit. The TP sensors then provide the control module with signal voltage proportional to throttle plate movement. Both TP sensor signal voltages are low at closed throttle and increase as the throttle opens.

[blindsquirrel]

And, if we assume that the normal full-range TP1/TP2 voltages should go from something like 0.5-4.5v, then if your throttle blade is only being commanded to open ~50%, then your measured voltages would be correct.

Is the throttle blade only opening halfway?

Have you removed the pedal from the floor and pushed it fully to the stop? Does the throttle blade still only open halfway?

Where are you sourcing wiring info to verify you've got the correct APP connector pinning? Please don't say something like Autozone.

[VF1000R]

yes on 2004 Escalade.

my info is that if commanded WOT , voltage is supposed to be around 4.5. Blade is actually opening about 1/3 of the way. Pulled pedal and made sure it was going full swing. Same voltage issue.

Harness is custom from CP in Florida at over $1000.

Im concerned that its in the programming. Shop says no, blames harness. Funny , it worked fine , 400hpRW, then they tweaked the tune a couple times dealing with a low speed issue. my ECM is Blue Green and evidently that was a struggle for them.

[blindsquirrel]

Does pedal position go from 0-100%, in the scanner? What does it say for throttle actual & commanded?

But hang on... are you tuning this? If you have your own interface and can go in and check/change things to test, that's OK. But trying to figure out how somebody else did something that messed it up? Not sure I want to get into that sort of thing.

[VF1000R]

Does pedal position go from 0-100%, in the scanner? What does it say for throttle actual & commanded?

But hang on... are you tuning this? If you have your own interface and can go in and check/change things to test, that's OK. But trying to figure out how somebody else did something that messed it up? Not sure I want to get into that sort of thing.

Dont blame you, neither do I , yeah shop tune. I was just looking for help to see if programming could cause this. Shop is saying its commanded 100% , obviously its not going 100%.

[blindsquirrel]

Somebody would really need to look at a compare log between the when-it-worked tune and the after-it-broke tune to see what was messed with. Even then it might not be obvious.

Seems like the shop could prove it isn't their tune by loading a copy of the old tune back in it... and it sounds like they aren't offering to do that.

The only thing that sounds like similar symptoms is when you swap an adjustable pedal for a non-adjustable or vice versa, but you say none of the hardware changed between then and now so I can't see how that would be related.

[VF1000R]

Somebody would really need to look at a compare log between the when-it-worked tune and the after-it-broke tune to see what was messed with. Even then it might not be obvious.

Seems like the shop could prove it isn't their tune by loading a copy of the old tune back in it... and it sounds like they aren't offering to do that.

The only thing that sounds like similar symptoms is when you swap an adjustable pedal for a non-adjustable or vice versa, but you say none of the hardware changed between then and now so I can't see how that would be related.

Thats what I would do , but due to a unforseen accident, the shop laptop caught fire when a badly wired ecm burned up their puter and lost all program history, they actually had me bring the car back in so they could download my tune.

[VF1000R]

Thats what I would do , but due to a unforseen accident, the shop laptop caught fire when a badly wired ecm burned up their puter and lost all program history, they actually had me bring the car back in so they could download my tune.

DavidBaileyTunedfilepulledon82319Original.hpt