Chevy

Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

I have a po300 and po410 codes coming on on my chevy blazer…

Customer Question
I have a po300...

I have a po300 and po410 codes coming on on my chevy blazer 2001

Mechanic's Assistant: Just to clarify, what's the exact code? And have you tried to reset it?

Those are the exact codes, it has to do with the secondary air injection system and misfires

Mechanic's Assistant: Are you fixing your Blazer yourself? What have you tried so far?

I don't really know what to fix, there are a lot of variables to this issue and I am not a mechanic

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

I failed the emissions test due to these codes showing up, but it also lists some of the issues that could be causing this as ready in the computer

Submitted: 8 months ago.Category: Chevy
Show More
Show Less
Ask Your Own Chevy Question
Answered in 1 minute by:
11/15/2017
Chevy Mechanic: Roy, import/domestic specialest replied 8 months ago
Roy
Roy, import/domestic specialest
Category: Chevy
Satisfied Customers: 7,729
Experience: ASE master tech for 40 years
Verified

hello, my name is ***** ***** I will be glad to assist you. please allow me a couple of minutes to gather some basic info.

Roy

Ask Your Own Chevy Question
Chevy Mechanic: Roy, import/domestic specialest replied 8 months ago

ok

300 is a random missfire. could be plugs worn if not replaced lately. other than that, I would start with checking the fuel pressure. low fuel pressure from a bad fuel pump will cause this code.

looking up the 410

Roy

Ask Your Own Chevy Question
Customer reply replied 8 months ago
but the codes indicate secondary air injection problem
Chevy Mechanic: Roy, import/domestic specialest replied 8 months ago

410

this code most likely failure is the air pump itself but must be checked to verify. do you have a scn tool to turn this system on and off??

just the 410 does, the 300 is a different code

Roy

Circuit Description

The Secondary Air Injection (AIR) System is designed to lower exhaust emission levels during a cold or warm start. The AIR pump is timed to remain ON for approximately one minute after the engine is started.

The powertrain control module (PCM) commands the AIR pump relay ON by supplying a ground on the control circuit. This action energizes the AIR pump, forcing air into the exhaust stream. The PCM also commands the AIR vacuum control solenoid valve ON which applies vacuum to the AIR shut-off valve. When vacuum is applied to the AIR shut-off valve, airflow from the AIR pump flows through the hoses/pipes and to the exhaust check valves. The air then enters into the exhaust stream. The air that is introduced into the exhaust system accelerates catalyst operation by decreasing the time it takes for the convertor to begin its process of burning the incomplete gases; reducing engine exhaust emission levels. When inactive, the check valves and the shut-off valve prevent airflow in either direction.

The PCM detects a system airflow problem by monitoring the heated oxygen sensors (HO2S) and short term fuel trim during normal Open Loop AIR system operation. This is called a passive test. If the passive test indicates a pass, the PCM takes no further action. If the passive test fails or is inconclusive, the diagnostic will proceed with an intrusive or active tests. The PCM will command the AIR system ON during Closed Loop operation under normal operating conditions. The active test will pass or fail based on the response from the HO2S. A lean HO2S response indicates that the secondary AIR system is functioning normally. An increasing short term fuel trim value also indicates a normally functioning system. The AIR diagnostic consists of the passive test and the active tests. The AIR diagnostic requires failure of the passive and active tests on two consecutive key cycles to illuminate the malfunction indicator lamp (MIL) and store a DTC. If the PCM detects that the HO2S and short term FT did not respond as expected on one of the engine banks, DTC P1415 or P1416 sets. If the PCM detects that the HO2S and short term FT did not respond as expected on both of the engine banks, DTC P0410 sets.

Conditions for Running the DTC

- DTCs P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0155, P0171, P0172, P0174, P0175, P0300, P0440, P0442, P0446, P0506, or P0507 are not set.
- The engine run time is more than 15 seconds after Closed Loop operation.
- The engine load is less than 33 percent.
- The engine air flow is less than 18 g/s.
- The engine speed is more than 750 RPM.
- The ignition voltage is more than 11.7 volts.
- The engine coolant temperature (ECT) is 70-110 C (158-230 F).
- The intake air temperature (IAT) is more than 2 C (36 F).
- The fuel system is not operating in power enrichment or deceleration fuel cut-off (DFCO).
- The short term fuel trim is between +5 and -5 percent.
- The startup ECT is below 80 C (176 F).
- The vehicle speed is more than 25 km/h (15 mph).

Conditions for Setting the DTC

- The HO2S voltage does not decrease to less than 222 mV within 1.2 seconds when the AIR pump turns on during Closed Loop operation.
AND
- Short term fuel trim does not increase above a predetermined amount.

Action Taken When the DTC Sets

- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC

- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- 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.

- Using Freeze Frame/Failure Records may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records can aid in determining how many miles the vehicle has been driven since the DTC set. The Fail Counter and Pass Counter can also aid in determining how many ignition cycles the diagnostic reported a pass 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.
- An intermittent may be caused by any of the following conditions:
- Low system air flow may cause this DTC to set.
- Excessive exhaust system back pressure
- Moisture, water, or debris ingested into the AIR pump
- Pinched, kinked, heat damaged, or deteriorated hoses or vacuum hoses
- Restriction in the pump inlet, duct, or filter
- 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.
- For an intermittent, refer to Intermittent Conditions.
- When commanding the AIR system ON with a scan tool, the PCM will activate the AIR pump and the AIR solenoid. The fuel control system will then enter an Open Loop status. This action will allow fresh air to enter the exhaust stream and cause the HO2S mV parameters to drop to near 0 mV. This would indicate a properly operating system. However, if the AIR pump does not operate, or there is no air flow from the pump entering the exhaust stream due to a leak in the system, the HO2S parameter may still drop below 100 mV. This is due to fresh air being drawn into the exhaust stream from the check valve operation and the opening of the shut-off valve. The HO2S will respond with a drop in mV readings as a result of this air leaning out the exhaust gases. The voltages may drop below 100 mV, but not approach the near 0 mV parameter.
- An AIR pump which exhibits an exhaust noise through the pump may have an AIR solenoid or AIR shut-off valve stuck open. The short term fuel trims may indicate a higher than normal value. This condition may not set a DTC P0410.
- An AIR shut-off valve that has become inoperative and has shown indications of exhaust gases in the outlet port, or heat damaged hoses may indicate an exhaust check valve failure.
- The vacuum lines at the vacuum solenoid cannot be reversed. This condition may hold the shut-off valve open continually. The center port of the vacuum solenoid is the vacuum source.
- A vacuum solenoid leaking vacuum will hold the shut-off valve open. An exhaust noise may be heard through the air cleaner. Fuel trim values may also indicate a higher than normal value at idle. This DTC may not set.
- Leaking check valves will leave traces of exhaust carbon in the AIR system, with a possibility of heat damage to the hoses and shut-off valve.

Test Description

The numbers below refer to the step numbers on the diagnostic table.
4. This step will determine if the AIR system is functioning correctly.
16. This step determines if there is a short to voltage on the AIR pump supply voltage circuit. Allowing the AIR pump to operate continuously.
25. This step is to test for a short to voltage on the AIR solenoid supply voltage circuit keeping the AIR solenoid ON at all times.

Ask Your Own Chevy Question
Chevy Mechanic: Roy, import/domestic specialest replied 8 months ago

do you still need any help???

Please take a moment and rate my service 3 stars or better. that is the only way the site will pay me for my efforts.

Roy

Ask Your Own Chevy Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a chevy mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Roy Your Own Question
Roy
Roy
Roy, import/domestic specialest
Category: Chevy
Satisfied Customers: 7,729
7,729 Satisfied Customers
Experience: ASE master tech for 40 years

Roy is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money.

Todd LRochester NY

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

GM Tech (Cam)

GM Tech (Cam)

Chevy Technician

15,659 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Gary

Gary

Chevy Technician

9,621 satisfied customers

15 years GM master tech

Tim&#039;s Auto Repair

Tim's Auto Repair

mechanic

8,884 satisfied customers

Have owned a repair shop for 25 yrs.

Dave Nova

Dave Nova

Chevrolet Technician

7,092 satisfied customers

ASE Master Certification. GM World Class Certification

John

John

Master A.S.E Automotive technician

4,071 satisfied customers

A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician

Don - Mo Lurch

Don - Mo Lurch

Auto Mech / Electronics

2,948 satisfied customers

Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

Ron Z.

Ron Z.

- Chevy Tech -

2,822 satisfied customers

18+yrs experience. State Inspector and Chevy Diagnostics

< Previous | Next >

Related Chevy Questions
I got a po410 code reading car starts and dies instantly but
i got a po410 code reading car starts and dies instantly but maybe in an hour it may start with no problem it starts most of the time but every once in awhile it won't … read more
Roy
Roy
import/domestic specialest
7,729 satisfied customers
The code po410 came up ,I replace two air valve that work
the code po410 came up ,I replace two air valve that work one day then it came up again … read more
Gunvir Singh
Gunvir Singh
1,949 satisfied customers
I keep getting po410 code, PO410 and yes reset it several
PO410 and yes reset it several times replaced fuse and air flow valve … read more
Kavey
Kavey
86 satisfied customers
chevy Trailblazer 4x4: check engine light on a 2005 trailblazer,code
check engine light on a 2005 trailblazer,code of po410 secondary air injection system. that is the only code. what do I need to do fix it ?… read more
Roy
Roy
import/domestic specialest
7,729 satisfied customers
Chevrolet Tahoe 4x2: I have a 2000 chevy tahoe (new) 5.3 v8
I have a 2000 chevy tahoe (new) 5.3 v8 2wd. cant pass smog engine light was on., Had it reset before smog. Smog shows rejected - not failed - the parameters were as follows: OBD sec air ; OBD Evap: ox… read more
Roy
Roy
import/domestic specialest
7,729 satisfied customers
2001 chevy blazer: am getting code..secondary air injection
i have a 2001 chevy blazer and i am getting code p0410 secondary air injection system fault. Any idea what that means?… read more
Ron Z.
Ron Z.
- Chevy Tech -
Vocational, Technical or Trade Scho
2,822 satisfied customers
1999 Chevy blazer: evap Emissions..mass air, no help..rattling
1999 Chevy Blazer 4.3L Current codes: P0101 Mass Airflow Circuit out of range P0300 Engine Misfire P0410 Secondary Air Injection System P0440 Evap Emissions System Fault P1416 Air System Fault (bank 2… read more
rodcuda
rodcuda
Auto repair pro, 30 years experience
Associate Degree
74 satisfied customers
2000 blazer: check engine lite..readings..oxygen sensor heater
I recently had an issue with the check engine lite on my 2000 blazer. I had it repaired. The computer was cleared out and I currently have not ready readings on;Secondary air systems,oxygen sensor hea… read more
supermechanic
supermechanic
Service consultant
Vocational, Technical or Trade Scho
10 satisfied customers
2000 chevy blazer: service engine light..code tester..malfunction
2000 chevy blazer 4.3 engine service engine light is on, code tester says secondary engine inhector malfunction what needs to be replaced or repaired.… read more
Dave Nova
Dave Nova
Chevrolet Technician
Associate Degree
7,092 satisfied customers
2001 chevy blazer hard to start cranks 8 to 10 seconds before
2001 chevy blazer hard to start cranks 8 to 10 seconds before starting stalls and dies all of a sudden shows po410 code… read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
2000 chevy malibu: emissions..an engine code po412..secondary air
I have a 2000 chevy malibu that was manufactured to california emissions. I live in Georgia. The computer is generating an engine code po412 for secondary air injection system problem. My mechanic can… read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
2001 chevy blazer: a code of po410 which is the secondary AIR system
my 2001 chevy blazer is throwing a code of po410 which is the secondary AIR system. I checked the fuses for the air pump and the 50 and 10 are both good which to me means the pump should be good what … read more
Chevy
Chevy
Associate Degree
242 satisfied customers
2001 Chevy: service engine light..connector..u 4.3W manual trans 4wd
service engine light "ON" secondary air injection code replaced air pump "upgraded model with raised connector higher in engine bay" same code - light does not come on immediately (30 miles engine off… read more
Clayso
Clayso
Lead Technician
ASE Master Technician 1999
274 satisfied customers
1999 pontiac: check first..located under..the hood thanks..Ron
HI I have a 1999 pontiac formula with a 5.7 70000 miles codes are po410 po412 po418 what should i check first and where are the parts located under the hood thanks for your help Ron… read more
GMTechBernard
GMTechBernard
Owner / Technician
High School or GED
1,644 satisfied customers
Blazer: misfiring..coil..fuel regulator, web, the timing chain, intake
I have a 2001 Xtreme Blazer. We are having problems with it misfiring. We have replaced the fuel coil, fuel regulator, web, the timing chain, intake, distributor, and then a gear on the distributor. W… read more
RussMasterTech
RussMasterTech
GM Service Technician
3 Years College
546 satisfied customers
2001 Blazer: driven for over 250 mile..secondary air..evaporative
I have a 2001 Blazer keeps throwing a P0410 code along with we have driven for over 250 mile since the code has been reset and the computer keeps saying that the secondary air system and the evaporati… read more
Mcgruder73
Mcgruder73
Auto Technician
Associate Degree
2000 Corvette: automatic..headers..week the check engine light came on
Help me. I have a 2000 Corvette automatic. I had new headers put on and after about a week the check engine light came on. The computer said that it was restricted air flow for the secondary air. I to… read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
2001 CHEVY BLAZER: I REPLACED THE SMOG PUMP..HOSE..GM..KEEPS COMING
I HAVE A 2001 CHEVY BLAZER WITH A PO410 COMPUTER CODE THAT COMES UP. I REPLACED THE SMOG PUMP AND INSTALLED THE UPDATED HOSE THAT GM TOLD ME TO CHANGE. I CLEARED THE COMPUTER BUT THE CODE KEEPS COMING… read more
frank
frank
Vocational, Technical or Trade Scho
1,892 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x