PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Still having problems

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Old Jul 14, 2017 | 03:38 PM
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Default Still having problems

I want to link a thread here as I now suspect the PCM as the problem!

https://ls1tech.com/forums/automatic...-problems.html


I sure hope somebody can help me as I am out of options.
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Old Jul 18, 2017 | 05:51 PM
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Still haven't got my truck fixed ..... We have gone over and over it, and had a couple pros scan with various scanners and all say they think it is the PCM

We swapped in a LQ9 in my 2000 GMC and replaced the 5.3 and I sent my comp off to be re-flashed while the motor was replaced.

It shifts even if on the floor in the 2000 RPM range and is a total dog even if I jerk it down in low and floor it! (does not shift out then)

No grounds are loose as we triple checked all.
TPS has been replaced and manually voltage tested.

It is popping two codes:
P0122
Throttle/Petal Position sensor A Circuit low input

P1635
5 volt reference (A or 1) Circuit

Then the same code a different way

P0122
1. Throttle Position (TP) sensor 1. Circuit low Voltage 2. Throttle Position (TP) sensor Circuit low
P1635
5 volt reference (A or 1) Circuit

Any idea what could be causing it.
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Old Jul 18, 2017 | 07:42 PM
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You probably are in REP and that's why the it feels like a dog ... get that TPS fixed


QUOTE=ACAMS;19678493]Still haven't got my truck fixed ..... We have gone over and over it, and had a couple pros scan with various scanners and all say they think it is the PCM

We swapped in a LQ9 in my 2000 GMC and replaced the 5.3 and I sent my comp off to be re-flashed while the motor was replaced.

It shifts even if on the floor in the 2000 RPM range and is a total dog even if I jerk it down in low and floor it! (does not shift out then)

No grounds are loose as we triple checked all.
TPS has been replaced and manually voltage tested.

It is popping two codes:
P0122
Throttle/Petal Position sensor A Circuit low input

P1635
5 volt reference (A or 1) Circuit

Then the same code a different way

P0122
1. Throttle Position (TP) sensor 1. Circuit low Voltage 2. Throttle Position (TP) sensor Circuit low
P1635
5 volt reference (A or 1) Circuit

Any idea what could be causing it.[/QUOTE]
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Old Jul 18, 2017 | 09:49 PM
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Originally Posted by T/A KID
You probably are in REP and that's why the it feels like a dog ... get that TPS fixed
I replaced the TPS, and it shows proper voltage .... THEY SAY.
Iran fine before the swap and tune.

It doesn't feel like a dog, it IS a dog, I can outrun it through the quarter on my bicycle and I am nearly 60.
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Old Jul 18, 2017 | 09:54 PM
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I have a guy coming tomorrow that is real good with these trucks and he has a Snap-on scanner ..... don't think they have tried one yet.

All the other scanners are showing my engine to be a 5.3 ..... gonna see what the Snap-on says
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Old Jul 18, 2017 | 10:27 PM
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Originally Posted by ACAMS
I replaced the TPS, and it shows proper voltage .... THEY SAY.
Iran fine before the swap and tune.

It doesn't feel like a dog, it IS a dog, I can outrun it through the quarter on my bicycle and I am nearly 60.
Its Bc it's in REP
reduced engine power..
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Old Jul 18, 2017 | 10:31 PM
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Is REP the same as what many call Limp-Home Mode?
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Old Jul 18, 2017 | 10:33 PM
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Originally Posted by G Atsma
Is REP the same as what many call Limp-Home Mode?
yes!!
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Old Jul 18, 2017 | 11:24 PM
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Thought so! Wasn't positive, so THANK YOU!
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Old Jul 19, 2017 | 12:35 PM
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Acams any luck!?
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Old Jul 19, 2017 | 04:06 PM
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They are working on it now ..... Trying to get the other guy with the Snap-on scanner to come help.
They had a trainee do a lot of my engine swap and as you know it has been a month, I just started getting on them regularly.
I don't mind the trainee learning on my truck and really don't mind waiting a month, but now it is time to get my truck going no matter what it takes.
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Old Jul 19, 2017 | 04:11 PM
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Originally Posted by ACAMS
They are working on it now ..... Trying to get the other guy with the Snap-on scanner to come help.
They had a trainee do a lot of my engine swap and as you know it has been a month, I just started getting on them regularly.
I don't mind the trainee learning on my truck and really don't mind waiting a month, but now it is time to get my truck going no matter what it takes.
Get that throttle issue fixed and it will run awesome!! It's throwing a fought with the low TPS values and therefore putting it into REP
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Old Jul 24, 2017 | 02:47 PM
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The guy that is good at that came by on his 30 Min lunch break with his snap-on scanner and said the TPS was not getting signal from the computer.
Is there a way to check the computer?
Can we get the PCM out of another truck with same type controls and stick it in just to test ...... I need my truck.
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Old Jul 24, 2017 | 03:26 PM
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Originally Posted by ACAMS
The guy that is good at that came by on his 30 Min lunch break with his snap-on scanner and said the TPS was not getting signal from the computer.
Is there a way to check the computer?
Can we get the PCM out of another truck with same type controls and stick it in just to test ...... I need my truck.
check wires to ECU... this whole time it's been in REP... you get that fixed and this truck will run solid!!
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Old Jul 24, 2017 | 03:34 PM
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What are the codes!??

could just need a new TB
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Old Jul 24, 2017 | 09:25 PM
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No signal to TPS ...... ran fine until the swap!

I should have KNOWN not to make two changes at the same time .... should have had motor installed and running, THEN sent computer off to be flashed for the 6.0
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Old Jul 24, 2017 | 09:27 PM
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Originally Posted by T/A KID
check wires to ECU
They have been checking them for two weeks, looks like I am gonna have to get it and take it to another shop to find the problem!

UNLESS you know of a good easy way to check them.
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Old Jul 24, 2017 | 11:44 PM
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Originally Posted by ACAMS
They have been checking them for two weeks, looks like I am gonna have to get it and take it to another shop to find the problem!

UNLESS you know of a good easy way to check them.
Which code!??? That would be a great start to diagnose the problem
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Old Jul 25, 2017 | 09:44 AM
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Code P0122 and P1635
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