Service engine soon light is on

Hello,

Lets get the code by following this guide and get back to us.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.

Roy

Hi there,

i would start with checking that the fuel pressure is with in specs and that the pressure regulator is not leaking and is working as it should, start here.

Mark (mhpautos)

Check engine light:

Have the computer scanned for code/s-you have a problem within the engine management system that caused the CEL to turn on-This is your starting point of diagnosis, finding out what's going on.

XTooltipElement
Service Information
2001 Chevrolet Tahoe - 4WD | Sierra, Silverado, Suburban, Tahoe, Yukon (VIN C/K) Service Manual | Document ID: 664110

DTC P1415 or P1416
Circuit Description
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 heated oxygen sensor (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 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, the diagnostic trouble code (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.

Conditions for Running the DTC
"Â DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0154, P0155, P0157, P0158, P0161, P0170, P0171, P0172, P0173, P0174, P0175, P0200, P0300, P0335, P0336, P0351, P0352, P0353, P0354, P0355, P0356, P0357, P0358, P0440, P0442, P0446, P0506, P0507, P1133, P1134, or P1258 are not set.

" The startup engine coolant temperature (ECT) is less than 70 °C (158 °F).

"Â The engine run time is more than 2 seconds.

"Â The manifold absolute pressure (MAP) sensor is more than 75 kPa.

"Â The engine load is less than 40 percent.

"Â The engine air flow is less than 20 grams per second.

"Â Engine speed is more than 900 RPM.

"Â The vehicle speed is more than 15 km/h (25 mph).

"Â The ignition voltage is more than 11.7 volts.

"Â The air fuel ratio is 13.125:1.

" The ECT is between 70-110 °C (158-230 °F).

" The intake air temperature (IAT) is more than 2-100 °C (36-212 °F).

"Â The fuel system is not operating in power enrichment or deceleration fuel cut-off (DFCO).

"Â The short term fuel trim is in cells 5 or 6.

Conditions for Setting the DTC
"Â The HO2S voltage does not go below 222 mV for 1.2 seconds or more.

"Â Short term fuel trim does not go above a predetermined amount.

Action Taken When the DTC Sets
"Â The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

"Â The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC
"Â The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

"Â A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

"Â A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

"Â Clear the MIL and the DTC with a scan tool.

Diagnostic Aids
Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

"Â Casting flash in the exhaust manifold may restrict the amount of air flow necessary to affect the HO2S voltage. If you suspect this, remove the air pipe from the manifold and inspect the passage.

"Â Using the Freeze Frame/Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same Freeze Frame conditions such as RPM, load, vehicle speed, temperature etc. That you observed. This will isolate when the DTC failed.

"Â For an intermittent condition, refer to Symptoms - Engine Controls.

Test Description
The number below refers to the step number on the diagnostic table.

A check valve that flows in both directions causes heat damage to the AIR system components.

Step
Action
Values
Yes
No

Schematic Reference: Engine Controls Schematics

1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2
Important: Before proceeding with this diagnostic table ensure that the AIR pump is operating and that air is present at the outlet of the AIR shut-off valve. If the AIR pump is inoperative and no air is present at the outlet of the AIR shut off valve, refer to DTC P0410 for further diagnosis.

Install a scan tool.
Idle the engine in Closed Loop.
Turn OFF all the accessories.
Monitor the bank 1 sensor 1 left front HO2S voltage display on the Engine 1 Data List using a scan tool.
Enable the AIR pump using a scan tool.
Observe and record the Bank 1 Sensor 1 (Left Front) HO2S voltage, as the AIR pump is enabled.
Does the HO2S voltage drop below the specified value?
350 mV
Go to Diagnostic Aids
Go to Step 3

3
Visually and physically inspect all hoses and pipes for:

"Â Proper connections

"Â Clamps are secure on pipes and hoses

"Â No kinks, holes, or pinched hoses and pipes

"Â Components with evidence of heat damage

Are all of the above OK?
--
Go to Step 4
Go to Step 6

4
Disconnect the hose from the check valve at the left exhaust manifold.
Enable the AIR pump using a scan tool.
Is air present at the hose outlet?
--
Go to Step 7
Go to Step 5

5
Repair the restriction or blockage in AIR hoses/pipes between the left exhaust manifold and the point where the system branches to both sides of the engine.

Is the action complete?
--
Go to Step 8
--

6
Repair the condition found.

Is the action complete?
--
Go to Step 8
--

7
Replace the check valve. Refer to Secondary Air Injection Check Valve and Check Valve Pipe Replacement - Bank 1.

Is the action complete?
--
Go to Step 8
--

8
Use the scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 9
Go to Step 2

9
With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK

© 2008 General Motors Corporation. All rights reserved.

Hi:
Before you replace the O2 sensors, check to make sure that the wiring going to them isn't damaged or melted. If everything looks good, I would start with them. The fuel injectors usually hold up well on these vehicles. Have you checked fuel pump pressure?

Let me know.

Joe