Where is the diverter vavle for the air pump on an envoy

the air injection pump has a relay in the power distribution box that is controlled by the computer. it gets 12 volts when the relay is closed. the relay can be bad

12 volts. there is a relay that supplies 12 volts to the pump when closed. this relay is in the power distribution box.

The electric air pump has two lines intake air and exhaust air the exhaust air goes to a diverter valve on some models then travels to metal tube and separates to the air check valves on the injection tubes to the exhaust manifolds. the diverter valve has the vacuum line on it which goes to the electric switching valve and then to manifold vacuum.

Here is the definition of the code.

P0410 GMC Description An air pump is used on the vehicle to lower tail pipe emissions on start-up. The Powertrain Control Module (PCM) grounds the Air pump relay control circuit which energizes the Air pump. The PCM also grounds the Air combination valve vacuum control solenoid circuit, which energizes the Air vacuum control solenoid. Vacuum is then applied to both Air combination valve diaphragms which opens the shut off valves. The PCM enables both circuits simultaneously when Air system operations id desired. When the AIR system is active, then Air pump forces fresh air into the exhaust stream in order to accelerate catalyst operation. The AIR combination valves replace the conventional check valves. When the AIR system is inactive the shut off valves prevent air flow in either direction.
Possible causes - Faulty Vacuum hoses damaged
- Faulty Air Pump inoperative
- Air bypass solenoid harness is open or shorted
- Air bypass solenoid circuit poor electrical connection
- Air bypass solenoid leaking/blocked or stuck open/closed
- Air diverter valve leaking/blocked or stuck open/closed
Read more: http://engine-codes.com/p0410_gmc.html#ixzz2H3Wjt8f7

Hi,


The air pump in a 2005 envoy is located next to the frame approximately underneath the driver's feet. You will see rubber hoses coming down into this component.


Take care!!!!

It's an ongoing problem with Envoy. I had the same problem on the drivers side not getting cold air. It cost me $600. They said it was a door inside the dash that diverts the cold air and the hot air depending on what you want. Worked good for a year, and now the passenger side gets cold air and not hot. Another $600 going out the door.
The repair shop said that sometimes they can adjust it, but most of the time they have to replace it. Good Luck

try disconnecting the battery for 5 mins. see if the computer resets

1997 BMW 328I 2.8L Customer Concern: MIL is on with trouble codes P1421 and P1423, for incorrect secondary airflow on both cylinder banks. Tests/Procedures: 1. Perform a functional test of the Air Injection Reaction (AIR) system. Tee a vacuum gauge into the vacuum hose attached to the diverter valve, located on the cylinder head towards the front of the engine.

2. Allow the vehicle to sit over night. Start the engine (cold) while monitoring the amount of vacuum on the gauge at startup. At temperatures from -10 to 40 degrees Celsius, there should be at least 17 inches of vacuum. At the same time, the AIR pump should run and pump a large volume of air into the exhaust. Potential Causes: A.I.R. Pump
Air Pump Relay
Restricted Cylinder Head
Diverter Valve
Tech Tips: These codes are related to a problem detected in the Secondary Air Injection system. Scan tools with BMW software include a feature to command the AIR pump on and off. The pattern failures for these codes are the AIR pumps due to leaks in the diverter valve and moisture or condensation in the AIR pump.

Possible fix but not all items. Just areas to look at:
Confirmed Fix - A.I.R. Pump - A.I.R. Diverter - A.I.R. Pump, Air Injection Reaction Diverter (AIRD) Valve - Air Injection Reaction Diverter (AIRD) Valve - Check Valve, Secondary Air Pump - Diverter Valve Vacuum Lines

The check valve is #12619128 and the gasket is #24577193. I think $65 and $75 respectively you can try websites like parts4chevy.com and gmpartsdirect.com. 
your talking about the diverter valve for the AIR pump. In which case it is easy to do and its easily accesible in the engine bay. The valve is located at the passenger side by the transmission dipstick tube under the intake tube. Good luck

its a hvac mode accuator it controls where the air blows i have the same problem with my envoy waiting on the part in the mail its up under the dash. the part is vin specific so check for the part number with a dealer they told me $103 but i found one online for $57