Trouble Codes for 01 Grand Prix GT
MikeGT01
03-25-2009, 10:33 AM
Hello all,
To recap an earlier post. I have a 01 Grand Prix GT 3.8L engine (no mods). I heard a thumping on the driverside. The response was to check my tires, I did and the tires are fine. Could it be a problem with the powersteering? I went to local Autozone because check engine light is on. They used an obd2 scanner an came back with these codes: 0128 and 1404.
To recap an earlier post. I have a 01 Grand Prix GT 3.8L engine (no mods). I heard a thumping on the driverside. The response was to check my tires, I did and the tires are fine. Could it be a problem with the powersteering? I went to local Autozone because check engine light is on. They used an obd2 scanner an came back with these codes: 0128 and 1404.
richtazz
03-25-2009, 10:53 AM
Welcome to AF
P0128....Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
This code indicates the coolant temperature is below what the PCM is programmed for and normally is corrected by installing a new thermostat. If a new t-stat doesn't help, then we can get further into it.
P1404....EGR Valve Circuit Performance - Actual Position > Commanded Position
This indicates that the EGR is opened further than the PCM is commanding it to be. This could be due to a bad EGR or an EGR sticking due to carbon build up.
P0128....Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
This code indicates the coolant temperature is below what the PCM is programmed for and normally is corrected by installing a new thermostat. If a new t-stat doesn't help, then we can get further into it.
P1404....EGR Valve Circuit Performance - Actual Position > Commanded Position
This indicates that the EGR is opened further than the PCM is commanding it to be. This could be due to a bad EGR or an EGR sticking due to carbon build up.
MikeGT01
03-25-2009, 11:46 AM
What can I use to clean the carbon build up?
Welcome to AF
P0128....Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
This code indicates the coolant temperature is below what the PCM is programmed for and normally is corrected by installing a new thermostat. If a new t-stat doesn't help, then we can get further into it.
P1404....EGR Valve Circuit Performance - Actual Position > Commanded Position
This indicates that the EGR is opened further than the PCM is commanding it to be. This could be due to a bad EGR or an EGR sticking due to carbon build up.
Welcome to AF
P0128....Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
This code indicates the coolant temperature is below what the PCM is programmed for and normally is corrected by installing a new thermostat. If a new t-stat doesn't help, then we can get further into it.
P1404....EGR Valve Circuit Performance - Actual Position > Commanded Position
This indicates that the EGR is opened further than the PCM is commanding it to be. This could be due to a bad EGR or an EGR sticking due to carbon build up.
Airjer_
03-25-2009, 12:56 PM
Carb/intake cleaner
BNaylor
03-26-2009, 10:11 AM
The first step before attempting cleaning the EGR valve and the manifold passage is to remove it and is to see if it is in fact sticking or stuck. Push in on the spring loaded pintle and see if it moves or snaps back. The P1404 is typically an electrical circuit malfunction related to the pintle positioning circuits and not mechanical.
Automotive Network, Inc., Copyright ©2025