Chevy

Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Chevy

Code 0452 (evap low signal)what do you look for wrong in 2001 blazer?

Customer Question
code 0452 (evap low signal)what do you look for wrong in 2001 blazer?
Submitted: 9 years ago.Category: Chevy
Ask Your Own Chevy Question
Answered in 18 minutes by:
12/8/2008
Chevy Mechanic: Super Mechanic, Master technician replied 9 years ago
Super Mechanic
Super Mechanic, Master technician
Category: Chevy
Satisfied Customers: 17,221
Experience: 29 yrs. exp., ASE master, cert. in G.M. electrical, a/c, susspension, brakes, electronic steering
Verified

Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.

 

It sounds like there may be just a bad fuel tank pressure sensor, or connection at it. Here is how it can be tested, along with the description and particulars of the code setting.

 

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) monitors the Fuel Tank Pressure (FTP) sensor signal in order to detect vacuum decay and excess vacuum during the enhanced Evaporative Emission (EVAP) diagnostic The PCM supplies a 5-volt reference and ground to the sensor. The FTP sensor signal voltage increases as the fuel tank pressure decreases (negative pressure or vacuum, high voltage). The FTP sensor signal voltage decreases as the fuel tank pressure increases (positive pressure, low voltage). This Diagnostic Trouble Code (DTC) sets when the FTP sensor signal goes below a predetermined value.

CONDITIONS FOR RUNNING THE DTC
The engine is running.

CONDITIONS FOR SETTING THE DTC

  • The fuel tank pressure sensor voltage is less than 0.1 volts.
  • All conditions present for greater than 5 seconds.

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.
  • Use a scan tool in order to clear the MIL and the DTC.

TEST DESCRIPTION

 

 

graphic

 

 

graphic

 

 

Ask Your Own Chevy Question
Customer reply replied 9 years ago
i replaced the fuel pump with a new one and had to rewire for a new type connector.that is the only change.i turned it (check engine)off with my scan but it came back on.
Chevy Mechanic: Super Mechanic, Master technician replied 9 years ago

You will want to make sure of the connection at the fuel pressure sensor, (1) and related wiring. Or, the sensor might just be bad.

 

 

graphic

Super Mechanic
Super Mechanic, Master technician
Category: Chevy
Satisfied Customers: 17,221
Experience: 29 yrs. exp., ASE master, cert. in G.M. electrical, a/c, susspension, brakes, electronic steering
Verified
Super Mechanic and 87 other Chevy Specialists are ready to help you
Ask your own question now
Ask Super Mechanic Your Own Question
Super Mechanic
Super Mechanic
Super Mechanic, Master technician
Category: Chevy
Satisfied Customers: 17,221
17,221 Satisfied Customers
Experience: 29 yrs. exp., ASE master, cert. in G.M. electrical, a/c, susspension, brakes, electronic steering

Super Mechanic 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

15,289 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Gary

Gary

Chevy Technician

9,357 satisfied customers

15 years GM master tech

Tim&#039;s Auto Repair

Tim's Auto Repair

mechanic

8,866 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

2,918 satisfied customers

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

Ron Z.

Ron Z.

- Chevy Tech -

2,734 satisfied customers

18+yrs experience. State Inspector and Chevy Diagnostics

< Previous | Next >

Related Chevy Questions
1989 5.7 liter throttle body engine. I was driving, engine
1989 5.7 liter throttle body engine. I was driving, engine was running fine, and came to stop sign. Upon trying to accelerate from the stop, the engine would hardly run. Bad miss and backfire visible … read more
rpmdiag
rpmdiag
High school
7,271 satisfied customers
1998 blazer takes longer to start when the engine is at
1998 blazer takes longer to start when the engine is at normal operating temperature after it's been off about 5 minutes or more. Starts up like new in the mornings after the engine has cooled down al… read more
Toyota Service
Toyota Service
Toyota Dealership Service & CR Manager
5,017 satisfied customers
Replaced the thermostat and display still shows up engine
replaced the thermostat and display still shows up engine hot ac off. i was told there is a way to reset it from the cluster. … read more
Gary
Gary
Chevy Technician
Vocational, Technical or Trade Scho
9,357 satisfied customers
I'm having issues with idling and stalling. Check engine
check engine light on yes. stall at idle only. I just replace the ignition control module and code p0300 has gone off but the same symptoms exist now it gives code p0106 … read more
Ron
Ron
Automotive Tech
Vocational, Technical or Trade Scho
35,256 satisfied customers
Engine idles high when cold and then pulsates for a while
engine idles high when cold and then pulsates for a while until it warms up … read more
Mike V.
Mike V.
technician
High School or GED
25,834 satisfied customers
How do I determine if the engine temperature sensor is
how do I determine if the engine temperature sensor is working properly in my 2005 Chevy Venture. … read more
Steve
Steve
Master\u0027s Degree
954 satisfied customers
2008 Chevrolet Tahoe. Intermittently the engine will not
2008 Chevrolet Tahoe. Intermittently the engine will not crank. I found if I wiggled the negative cable it would start. I have changed the battery and the Negative cable assembly but the problem has r… read more
Roy
Roy
shop foreman
Associate Degree
3,921 satisfied customers
1995 Suburban K2500 with 7.4L engine here. There is a loose
1995 Suburban K2500 with 7.4L engine here. There is a loose wire, dark green with a white stripe, running next to auxillary fan switch wire (light green). Right now it's not connected to anythimg, jus… read more
Mike S.
Mike S.
Vocational, Technical or Trade Scho
7,532 satisfied customers
The reduce engine message and the engine light on and alot
the reduce engine message and the engine light on and alot if shacking when I started it this morning … read more
Jared D
Jared D
Shop Supervisor
Bachelor\u0027s
2,002 satisfied customers
The engine shuts off, and its service traction control
the engine shuts off, and its service traction control popped up on the dash.. … read more
Steve
Steve
Master\u0027s Degree
954 satisfied customers
Check engine light not on with key on, Not on alt all with
Yes -performed tuneup replaced all sensors except knock … read more
Peter Zavarelli
Peter Zavarelli
General auto certifications
269 satisfied customers
Engine is running 240 degrees and not holding water/anti
engine is running 240 degrees and not holding water/anti freeze and heater is not working … read more
Edward
Edward
Professional at Justanswer.com
Associate Degree
3,175 satisfied customers
Check engine light on engine hot ac off message. Stay on.
check engine light on engine hot ac off message JA: Does the light stay on, or does it blink? Customer: stay on JA: What is the model/year of your Chevy? Customer: impala 2006 JA: Are you fixing your … read more
Ron
Ron
Automotive Tech
Vocational, Technical or Trade Scho
35,256 satisfied customers
I have a 2013 Tahoe with 5.3 engine. The service engine
I have a 2013 Tahoe with 5.3 engine. The service engine light comes on when the temperature drops below 45 degrees. It will go out when the temperature is above 45 or 50 degrees. The code it sets is P… read more
Eric
Eric
Retired
N/A
31,322 satisfied customers
Check engine light is on... It spudders at an idel. And
Check engine light is on... It spudders at an idel. And sometimes doesnt start .. … read more
Amedee
Amedee
Automotive Consultant
Vocational, Technical or Trade Scho
18,515 satisfied customers
The engine and traction control lights are on, and there is
The engine and traction control lights are on, and there is a "service traction" message on my 2011 Malibu. … read more
Mike V.
Mike V.
technician
High School or GED
25,834 satisfied customers
86 K10 temp. gauge goes to hot and engine dies, but engine
86 K10 temp. gauge goes to hot and engine dies, but engine is still cool … read more
Mike S.
Mike S.
Vocational, Technical or Trade Scho
7,532 satisfied customers
1996 chevy Silverado k2500 5.7 vortec engine engine light on
1996 chevy Silverado k2500 5.7 vortec engine engine light on po300 random misfire detected we replaced plugs wires Distributor cap and rotor pickup coil checked compression everything is good there ch… read more
Michael Solis
Michael Solis
363 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