[Z06] P0103 HC, Not going into Open Loop?
Thread Starter
Heel & Toe
Joined: Oct 2005
Posts: 22
Likes: 0
From: San Antonio Texas
P0103 HC, Not going into Open Loop?
Hello,
I recently replaced the PCM and MAF (stock), the PCM was reflashed to stock 2003 Z06 settings. I have PRC Stage 2.5 heads, Cam, SS Kooks LT headers and HF cats, stock TI the rest of the way. I am getting a good signal at the TB motor, the throttle plate is not binding. I am getting NO codes on the DIC other than the P0103 HC. I followed the dia. procedures for the code and have 5.02V at the MAF signal, and 12.08 volts on the IGN Feed pins in the harness.
On starting the RPMs are at 500 then go to 1000, and drops at a stop, then goes back to ~1000, etc.. The way it drives I do not think the PCM is going into open loop, but remaining in closed loop. I am planning on a new tune, but wanted to see if there was something I have overlooked. I have checked all the hoses, looked for air leaks after the MAF, etc., etc..
Is it possible with the above listed mods the air demand from the cam/heads is outside of the internal MAF table in the PCM at idle or low speeds?
Thanks in advance for any input.
I recently replaced the PCM and MAF (stock), the PCM was reflashed to stock 2003 Z06 settings. I have PRC Stage 2.5 heads, Cam, SS Kooks LT headers and HF cats, stock TI the rest of the way. I am getting a good signal at the TB motor, the throttle plate is not binding. I am getting NO codes on the DIC other than the P0103 HC. I followed the dia. procedures for the code and have 5.02V at the MAF signal, and 12.08 volts on the IGN Feed pins in the harness.
On starting the RPMs are at 500 then go to 1000, and drops at a stop, then goes back to ~1000, etc.. The way it drives I do not think the PCM is going into open loop, but remaining in closed loop. I am planning on a new tune, but wanted to see if there was something I have overlooked. I have checked all the hoses, looked for air leaks after the MAF, etc., etc..
Is it possible with the above listed mods the air demand from the cam/heads is outside of the internal MAF table in the PCM at idle or low speeds?
Thanks in advance for any input.
Thread Starter
Heel & Toe
Joined: Oct 2005
Posts: 22
Likes: 0
From: San Antonio Texas
More details. It has a G5X3 cam. It also has low speed surge, wild rpm swings when costing to a stop, cruise control effect on deceleration - which I attribute to the cam, and I know I can get tuned out. Driviability is not an issue with the cam, I just want it to run as good as it can. I know that I need to get it tuned for idle speed and airflow, VE and MAF tables, DFCO, etc..
Re-phrasing my original question/post - does anyone know of any other reason why I would be getting the P0103 HC code?
Re-phrasing my original question/post - does anyone know of any other reason why I would be getting the P0103 HC code?
Melting Slicks
Joined: Jul 2010
Posts: 3,355
Likes: 113
From: Los Angeles
EDIT: Actually, first you might want to use some MAF cleaner spray.
Last edited by skyavonee; Apr 1, 2013 at 01:36 PM.
Thread Starter
Heel & Toe
Joined: Oct 2005
Posts: 22
Likes: 0
From: San Antonio Texas
Thanks Skyavonee. The MAF I just installed was a NIB from GM - PN 25341604 (ACD# 213-1150). I am planning on getting it tuned either this week or early next. I will report back on what was done, and any issues, and how it runs and if any damaged sensors were found.
Thread Starter
Heel & Toe
Joined: Oct 2005
Posts: 22
Likes: 0
From: San Antonio Texas
I have a dyno tuning session scheduled next week here in San Antonio. I will get back with the results and numbers then.
Last edited by C3 Vette; Apr 5, 2013 at 07:25 PM. Reason: Change in tune date
