control systems O.B.D

[kenwood guy]

ok I flipped through a silverado repair manual and found the def. for the codes I have on my truck any of you guys got theses?? I own a v6 by the way. The truck is under warrenty(for what its worth ) and the work is going to be done by the guys at the dealer can somone fill me in to what there going to do??? on my invoice it said the there was low fuel pressure and the engine check valve was not getting any air output???? Anything you guys think I need to know would be a help
I got the following:

code P0171= System to lean Left bank
code P0174= System to lean Right bank
code P1416= Secondary air injection system malfunction,Right bank

The truck is still running and I have not noticed anything different if the truck needs a new fuel module, The module and the fuel pump are all one unit in the tank... true??? by the way the manager said thhat the fuel pressure is bleeding down it would hold at 55 and then drop to 50 he said normal specs call between 55 and 60 ) (I Think) and once I get everything fixed the light should go away.

Thany you

[GMMerlin]

Originally Posted by kenwood guy

ok I flipped through a silverado repair manual and found the def. for the codes I have on my truck any of you guys got theses?? I own a v6 by the way. The truck is under warrenty(for what its worth ) and the work is going to be done by the guys at the dealer can somone fill me in to what there going to do??? on my invoice it said the there was low fuel pressure and the engine check valve was not getting any air output???? Anything you guys think I need to know would be a help
I got the following:

code P0171= System to lean Left bank
code P0174= System to lean Right bank
code P1416= Secondary air injection system malfunction,Right bank

The truck is still running and I have not noticed anything different if the truck needs a new fuel module, The module and the fuel pump are all one unit in the tank... true??? by the way the manager said thhat the fuel pressure is bleeding down it would hold at 55 and then drop to 50 he said normal specs call between 55 and 60 ) (I Think) and once I get everything fixed the light should go away.

Thany you

Low fuel pressure will cause a lean air/fuel mixture.
Here is how the lean codes would be set
The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy and emission control. Fuel delivery is controlled differently during open and closed loop. During Open Loop the PCM determines fuel delivery based on sensor signals, without oxygen sensor input. During Closed Loop, the oxygen sensor inputs are added and used by the PCM to calculate short and long term fuel trim (fuel delivery adjustments). If the oxygen sensors indicate a lean condition, fuel trim values will be above percent. If the oxygen sensors indicate a rich condition, fuel trim values will be below 0 percent. Short Term fuel trim values change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long Term fuel trim makes coarse adjustments in order to maintain Air/Fuel Ratio of 14.7:1. If the PCM detects an excessively lean condition, this diagnostic trouble code (DTC) will set.



Here is how the SAI system works
A secondary air injection (AIR) pump is used on this vehicle to lower tail pipe emissions on start-up. The powertrain control module (PCM) supplies a ground to the AIR pump relay, which energizes the AIR pump and the AIR solenoid valve. Engine vacuum is applied to the AIR shut-off valve when the AIR solenoid is energized. The engine vacuum opens the AIR shut-off valve which allows air to flow to the exhaust manifolds.

The PCM monitors the HO2S voltages to diagnose the AIR system.

During the AIR test, the PCM activates the AIR pump during Closed Loop operation. When the AIR system is activated, the PCM monitors the heated oxygen sensor (HO2S) voltages and short term fuel trim values for both banks of the engine. If the AIR system is operating properly, the HO2S voltages should go low and the short term fuel trim should go high.

If the PCM determines that the HO2S voltages for both banks did not respond as expected during the tests, DTC P0410 sets. If only one sensor responded, the PCM sets either a DTC P1415 for bank 1 or P1416 for bank 2 to indicate on which bank the AIR system is inoperative.

[kenwood guy]

thanx