DTC P1416 Secondary Air Injection (AIR) System Bank 2. GMC Truck GMC C Pickup

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2000 🢒 GMC C Pickup - 2WD 🢒 Engine 🢒 Engine Controls - 7.4L 🢒 DTC P1416 Secondary Air Injection (AIR) System Bank 2

VCM Connector End Views
Engine Controls Components
A.I.R., IAC, and MAF Controls
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

A secondary air injection (AIR) pump is used on this vehicle in order to lower tailpipe emissions on start-up. The VCM supplies a ground to the AIR pump relay control circuit. This energizes the AIR pump relay and supplies voltage to the AIR pump clutch. The VCM uses the HO2S voltages and the short term fuel trim in order to diagnose the secondary air injection system.

The VCM monitors the HO2S voltages and the short term fuel trim value when the AIR pump is energized. This additional air causes the HO2S voltages to shift low, reflecting the leaner mixture. The short term fuel trim should increase above 128 confirming that the VCM is supplying additional fuel. The low HO2S voltages and higher short term fuel trim value provide confirmation that the secondary air injection system is operating properly. When the AIR pump is de-energized, the HO2S voltages should increase and begin switching normally.

If only one HO2S responded as expected, the VCM sets either a DTC P1415 or P1416 depending on which engine bank the AIR system is inoperative.

Conditions for Running the DTC

•	No active ECT sensor DTCs

•	No active IAC sensor DTCs

•	No active heated oxygen sensor DTCs

•	No active misfire DTCs

•	No active MAP sensor DTCs

•	No active fuel trim DTCs

•	No active EVAP system DTCs

•	No active TP sensor DTCs

•	No active IAT sensor DTCs

•	No active MAF sensor DTCs

•	The system voltage is more than 10 volts.

•	The IAT is more than 0°C (32°F).

•	The power enrichment mode is not active.

•	Decel fuel cut-off not active

•	The commanded air/fuel ratio is 14.7:1.

•	The engine speed is more than 550 RPM.

•	The engine load is less than 50 percent.

•	The MAF is less than 100 g/s.

•	The ECT is between 75°C and 105°C (167°F to 221°F).

•	The system has been in closed loop mode for more than 15 seconds.

Conditions for Setting the DTC

The VCM has not detected a change in HO2S voltage and short term fuel trim when the secondary air injection pump is energized.

Action Taken When the DTC Sets

The VCM will turn ON the malfunction indicator lamp (MIL) after two consecutive test cycles with the fault active.

Conditions for Clearing the MIL or DTC

•	The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.

•

A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.

•	Use a scan tool in order to clear the DTCs.

Diagnostic Aids

Intermittent conditions can be caused by wiring problems.

An intermittent may be caused by any of the following conditions:

•	A poor connection

•	Rubbed through wire insulation

•	A broken wire inside the insulation

Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

This step determines if the cause of the DTC is still present.

This step determines if there is a problem before or after the check valve.

Step

Action

Values

Yes

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Install a scan tool.
Start the engine and allow it to run for 2 minutes.
Verify the engine is at normal operating temperature and in closed loop.
Command ON the AIR pump with the scan tool.

Does the Short Term Fuel Trim Bank 2 indicate a change of more than the specified value within 30 seconds?

20%

Go to Step 3

Go to Step 4

The DTC is intermittent.

Are any additional DTCs stored?

Go to the applicable DTC table

Go to Diagnostic Aids

Inspect the AIR system Bank 2 for the following:

•	Hoses/pipes for proper connections

•	Secure hose clamps

•	Kinks, holes or pinched hoses/pipes

•	Loose fittings

•	Components with evidence of heat damage

Did you find a problem?

Go to Step 8

Go to Step 5

Disconnect the AIR hose at the Bank 2 check valve, AIR pump side.
Start the engine and allow it to idle.
Command ON the AIR pump with the scan tool.

Does air flow from the hose?

Go to Step 6

Go to Step 7

Inspect for restrictions or leaks in the check valve and the AIR pipe on Bank 2.

Did you find a problem?

Go to Step 8

Go to Diagnostic Aids

Inspect for restrictions or leaks in the Bank 2 AIR hose between the AIR shut off valve and the check valve.

Did you find a problem?

Go to Step 8

Go to Secondary Air Injection System Diagnosis

Repair as necessary. Refer to Secondary Air Injection Check Valve and Check Valve Pipe Replacement .

Is the action complete?

Go to Step 9

Using the scan tool, clear the DTCs.
Start the engine.
Allow the engine to run until the engine reaches normal operating temperature.
Select the DTC and Specific DTC function.
Enter the DTC number which was set.
Operate the vehicle, within the Conditions for Setting this DTC, until the scan tool indicates the diagnostic Ran.

Does the scan tool indicate the diagnostic Passed?

Go to Step 10

Go to Step 2

Using the scan tool, select Capture Info, Review Info.

Are any additional DTCs displayed that have not been diagnosed?

Go to the applicable DTC table

System OK