Error Code P129D Question

FLYNNZL1 · 06-17-2019, 09:31 AM

This weekend I was driving and I received this error code P129D along with a check engine light. I looked up the code it says, Fuel Pump Driver Control Module Ignition 1 Switch Circuit Low Voltage. The only mods a have done is Roto Fab CAI and Ported TB, both I did a year + ago. Any ideas? I am taking it to the dealer today, I hope they can just clear the code and that is it.

TJay74 · 06-17-2019, 01:40 PM

I got it on my 2017 SS 1LE about 2 years ago. Back then the code wasnt dedicated to the fuel pump cct and had a generic name to it. I will be interested in what the dealership finds.

I wonder if it means the FPCM is going out or has gone out. Please post up what they find as I am really interested.

FLYNNZL1 · 06-17-2019, 08:57 PM

The dealer kept my car overnight. They can not find anything wrong. They reset the Check Engine light, and it comes back on. They emailed GM to find out what to do next...

FLYNNZL1 · 06-18-2019, 03:33 PM

The dealer told me it was my Mild to Wild relay I put in. It is not a big deal to me, I was not really using it, I can always do the fuse pull. That being said, we will see if it happens again.

honus03 · 06-18-2019, 04:29 PM

I have the same issue. It first popped up a couple of weeks ago. Got the code cleared and then it popped up again yesterday. Dealer said something about it might need a update the first time it happened. I will have them check it when I take my car in for the Transmission flush for the dreaded TC issue.

FLYNNZL1 · 06-18-2019, 10:59 PM

I picked up my Camaro today. The dealer thinks my DYI Mild to wild relay was because they didn’t charge me anything they just disconnected it so far no code. I know the on ZL1 the fuses were a little bit different from the SS. I will update if it pops back up again.

TJay74 · 06-19-2019, 11:30 AM

Quote:

Originally Posted by FLYNNZL1

I picked up my Camaro today. The dealer thinks my DYI Mild to wild relay was because they didn’t charge me anything they just disconnected it so far no code. I know the on ZL1 the fuses were a little bit different from the SS. I will update if it pops back up again.

Dealer love to blame anything they can to get out of fixing electrical gremlins. When my 2016 Sierra had issues with the Infotainment system they blamed my dash cam for it.

Dealer hate diagnosing electrical issues, if they cant figure it out it causes a request to be made to the GM TAC line to have an engineer look into it further. A very long process when that happens.

honus03 · 07-02-2019, 03:27 PM

I have this code. Local dealership thought it was caused by my GM CAI that's been in the car for 2 years now because of what their scanner read. It read a totally different code then AutoZone and O'Reilly which both read the code as P129D. Gonna get the Pump Driver Control Module replaced when the part comes in.

honus03 · 07-17-2019, 05:13 PM

I got the module replaced. Didn't seem to work. 2nd time I started the car up the light and code popped back up. Now they are going to call GM and see what they say. Only thing that I have done to the car is add the Gen5diy radar detector power harness. But light didn't start coming on till a week or 2 after I added the harness.

FLYNNZL1 · 07-17-2019, 06:15 PM

I have the updated Gen5diy radar detector power harness. After they took out my mild to wild setup I have not haad the code return.

honus03 · 07-17-2019, 06:39 PM

I have the updated one too with the capacitor. I don't have a mild to wild switch so hopefully my dealer can figure it out.

TJay74 · 07-18-2019, 10:47 AM

I recently asked the dealer tech about this very code. He pulled the tech document, basically if at key on and start up the ECM voltage and the FPCM voltage vary more than 1v it will trip this error code.

He told me to not worry about it.

honus03 · 07-18-2019, 10:55 AM

Yeah. I was told not to worry about it too but it's annoying looking at the check engine light which as a by product causes the remote start not to function because there is a check engine light on.

rlarsen462 · 07-18-2019, 12:04 PM

I wonder if this is in any way related...given that you said the code you pulled with your reader (I'm using an Amazon BT OBD-II dongle and Torque) was different than what the dealer got. It's a long thread and I apparently still haven't resolved the overall issue at this point.

Coincidentally I also have the Gen5DIY harness (newer one with capacitor which solved the underlying radar detector issue) so I wonder if it's related.

06-17-2019, 09:31 AM	#1
FLYNNZL1 Wicked ZL1 Drives: 2017 ZL1 A10 HBM Join Date: Apr 2009 Location: Tucson, AZ Posts: 3,175 View My Garage	Error Code P129D Question This weekend I was driving and I received this error code P129D along with a check engine light. I looked up the code it says, Fuel Pump Driver Control Module Ignition 1 Switch Circuit Low Voltage. The only mods a have done is Roto Fab CAI and Ported TB, both I did a year + ago. Any ideas? I am taking it to the dealer today, I hope they can just clear the code and that is it. __________________ 2017 Hyper Blue Metallic ZL1 A10/CF Hood Insert/PDR/NAV MODS: Rotofab CAI/V-MAX CNC Ported Throttle Body/Clear Bra/LED Reverse Light/Rock Guards/Lift Pads/Darkened Tail Lights/Ghost-Tinted LED Side Markers/Darkened 3rd Brake Light

06-17-2019, 01:40 PM	#2
TJay74 Drives: 17 Camaro SS 1LE & 16 Sierra AT CC Join Date: Nov 2016 Location: Norman, OK Posts: 2,424	I got it on my 2017 SS 1LE about 2 years ago. Back then the code wasnt dedicated to the fuel pump cct and had a generic name to it. I will be interested in what the dealership finds. I wonder if it means the FPCM is going out or has gone out. Please post up what they find as I am really interested. __________________ 2019 Corvette Z06 2LZ A8 - Halltech CAI, AWE non-catted X-pipe, Mamo V2 ported TB 592rwhp, bone stock 566rwhp 2017 Camaro SS 1LE - Procharger D1SC w/ Tial 2" BOV & Race intercooler / ARH full length catless headers / Alky meth injection system - 650rwhp on conservative tune SOLD

06-17-2019, 08:57 PM	#3
FLYNNZL1 Wicked ZL1 Drives: 2017 ZL1 A10 HBM Join Date: Apr 2009 Location: Tucson, AZ Posts: 3,175 View My Garage	The dealer kept my car overnight. They can not find anything wrong. They reset the Check Engine light, and it comes back on. They emailed GM to find out what to do next... __________________ 2017 Hyper Blue Metallic ZL1 A10/CF Hood Insert/PDR/NAV MODS: Rotofab CAI/V-MAX CNC Ported Throttle Body/Clear Bra/LED Reverse Light/Rock Guards/Lift Pads/Darkened Tail Lights/Ghost-Tinted LED Side Markers/Darkened 3rd Brake Light

06-18-2019, 03:33 PM	#4
FLYNNZL1 Wicked ZL1 Drives: 2017 ZL1 A10 HBM Join Date: Apr 2009 Location: Tucson, AZ Posts: 3,175 View My Garage	The dealer told me it was my Mild to Wild relay I put in. It is not a big deal to me, I was not really using it, I can always do the fuse pull. That being said, we will see if it happens again. __________________ 2017 Hyper Blue Metallic ZL1 A10/CF Hood Insert/PDR/NAV MODS: Rotofab CAI/V-MAX CNC Ported Throttle Body/Clear Bra/LED Reverse Light/Rock Guards/Lift Pads/Darkened Tail Lights/Ghost-Tinted LED Side Markers/Darkened 3rd Brake Light

06-18-2019, 10:59 PM	#6
FLYNNZL1 Wicked ZL1 Drives: 2017 ZL1 A10 HBM Join Date: Apr 2009 Location: Tucson, AZ Posts: 3,175 View My Garage	I picked up my Camaro today. The dealer thinks my DYI Mild to wild relay was because they didn’t charge me anything they just disconnected it so far no code. I know the on ZL1 the fuses were a little bit different from the SS. I will update if it pops back up again. __________________ 2017 Hyper Blue Metallic ZL1 A10/CF Hood Insert/PDR/NAV MODS: Rotofab CAI/V-MAX CNC Ported Throttle Body/Clear Bra/LED Reverse Light/Rock Guards/Lift Pads/Darkened Tail Lights/Ghost-Tinted LED Side Markers/Darkened 3rd Brake Light

06-18-2019, 04:29 PM	#5
honus03 Drives: 1979 Camaro. 2016 2LT/RS V6 Join Date: Apr 2017 Location: Louisiana Posts: 43	I have the same issue. It first popped up a couple of weeks ago. Got the code cleared and then it popped up again yesterday. Dealer said something about it might need a update the first time it happened. I will have them check it when I take my car in for the Transmission flush for the dreaded TC issue.

07-02-2019, 03:27 PM	#8
honus03 Drives: 1979 Camaro. 2016 2LT/RS V6 Join Date: Apr 2017 Location: Louisiana Posts: 43	I have this code. Local dealership thought it was caused by my GM CAI that's been in the car for 2 years now because of what their scanner read. It read a totally different code then AutoZone and O'Reilly which both read the code as P129D. Gonna get the Pump Driver Control Module replaced when the part comes in.

07-17-2019, 05:13 PM	#9
honus03 Drives: 1979 Camaro. 2016 2LT/RS V6 Join Date: Apr 2017 Location: Louisiana Posts: 43	I got the module replaced. Didn't seem to work. 2nd time I started the car up the light and code popped back up. Now they are going to call GM and see what they say. Only thing that I have done to the car is add the Gen5diy radar detector power harness. But light didn't start coming on till a week or 2 after I added the harness.

07-17-2019, 06:15 PM	#10
FLYNNZL1 Wicked ZL1 Drives: 2017 ZL1 A10 HBM Join Date: Apr 2009 Location: Tucson, AZ Posts: 3,175 View My Garage	I have the updated Gen5diy radar detector power harness. After they took out my mild to wild setup I have not haad the code return. __________________ 2017 Hyper Blue Metallic ZL1 A10/CF Hood Insert/PDR/NAV MODS: Rotofab CAI/V-MAX CNC Ported Throttle Body/Clear Bra/LED Reverse Light/Rock Guards/Lift Pads/Darkened Tail Lights/Ghost-Tinted LED Side Markers/Darkened 3rd Brake Light

07-17-2019, 06:39 PM	#11
honus03 Drives: 1979 Camaro. 2016 2LT/RS V6 Join Date: Apr 2017 Location: Louisiana Posts: 43	I have the updated one too with the capacitor. I don't have a mild to wild switch so hopefully my dealer can figure it out.

07-18-2019, 10:47 AM	#12
TJay74 Drives: 17 Camaro SS 1LE & 16 Sierra AT CC Join Date: Nov 2016 Location: Norman, OK Posts: 2,424	I recently asked the dealer tech about this very code. He pulled the tech document, basically if at key on and start up the ECM voltage and the FPCM voltage vary more than 1v it will trip this error code. He told me to not worry about it. __________________ 2019 Corvette Z06 2LZ A8 - Halltech CAI, AWE non-catted X-pipe, Mamo V2 ported TB 592rwhp, bone stock 566rwhp 2017 Camaro SS 1LE - Procharger D1SC w/ Tial 2" BOV & Race intercooler / ARH full length catless headers / Alky meth injection system - 650rwhp on conservative tune SOLD

07-18-2019, 10:55 AM	#13
honus03 Drives: 1979 Camaro. 2016 2LT/RS V6 Join Date: Apr 2017 Location: Louisiana Posts: 43	Yeah. I was told not to worry about it too but it's annoying looking at the check engine light which as a by product causes the remote start not to function because there is a check engine light on.

07-18-2019, 12:04 PM	#14
rlarsen462 Sell Low, Buy High Drives: 2022 ZLE, 2023 ZLE (Inbound) Join Date: Feb 2019 Location: Varies Posts: 542	I wonder if this is in any way related...given that you said the code you pulled with your reader (I'm using an Amazon BT OBD-II dongle and Torque) was different than what the dealer got. It's a long thread and I apparently still haven't resolved the overall issue at this point. Coincidentally I also have the Gen5DIY harness (newer one with capacitor which solved the underlying radar detector issue) so I wonder if it's related.

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