How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask AMEDEE Your Own Question
Category: Chevy
Satisfied Customers: 23917
Experience:  ASE certified tech ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
Type Your Chevy Question Here...
AMEDEE is online now
A new question is answered every 9 seconds

2004 Impala: intermitent..Good battery and new starter and crank relay

Customer Question

Please help with 2004 Impala 3.8 intermitent no start. Good battery and new starter and crank relay. I am an old school mechanic out of the trade for 24 years but still try and do what I can. This has been going on for a month now. Car may start 30 times no problem and then does not crank. Then starts after a short wait (20 - 30 minutes).
First time it happened I pulled the relay out marked crank relay and banged it a few times, put it back and it started so I replaced it. A week later same thing.
Next time it happened I banged the starter with a hammer and it started so I replaced the starter. Went on a 1,000 mile trip with no problems. Got home and same thing. This time waited 10 minutes and it started.
I have also noticed the security light comming on from time to time and it has been only since the intermittent no start has been occurring.
Today I thought I would get old school smart and put a jumper button under the hood to activate starter solenoid from jumper button if it happened again. When I tried it it cranked but when I turned the key to on and jumped the starter it cranked but did not start. Security light came on so obviously the security circuit disabled fuel supply. I pulled the jumper button out and again had a no start condition from key. I rebooted the battery and still no start. I finally but the car in neutral, rolled back a few feet, put it in park and it started.

What do you think is going on. What is left? Neutral switch, ignition switch or security system malfunction???? Can the security system be disabled? No body would want to steel this P.O.S. anyay. Please help.

Tom Fitsell [email protected]
Submitted: 5 years ago.
Category: Chevy
Expert:  AMEDEE replied 5 years ago.
Hello and Welcome to Just Answer. My name is XXXXX XXXXX I will try my best to assist you and your 100% satisfaction is my goal. I have been working on these vehicles for over 10 years so I am very familiar with this system and how they work. However, keep in mind, that I need some solid concrete facts/evidence/clues from you in order to give you a good answer about your vehicle. Please realize that all my answers are based solely on the info that you provide me with.

Chances are you just have a bad pass lock sensor inside the ignition switch. This sensor inside the ignition switch receives a reference voltage from the BCM when turning the key on. This means that the sensor inside the ignition switch is considered to be a hall affect sensor. When turning the key on, the pass lock sensor receives 5 volts from the BCM. IT will then send a voltage reading back to the BCM after it goes through the resistor. The voltage going back to the BCM will be considerably lower than 5 volts because it went through the resistor thus lowering the voltage. The BCM "learns" this reading over time. The voltage reading coming back into the BCM needs to be the same every time the key is turned on. If not, then this is what causes the no start condition. Sometimes the BCM will "forget" this value or sometimes the ignition switch will start to go bad and will not send out the same voltage reading each time the key is turned on thus resulting in this no start condition. That is when a relearn procedure usually does the trick. If not, the ignition switch usually needs to be replaced.

Here is the relearn procedure.

Turn ON the ignition, with the engine OFF.

Attempt to start the engine, then release the key to ON, vehicle will not start.
Observe the SECURITY telltale. After approximately 10 minutes , the telltale will turn OFF. The vehicle is now ready to relearn the Pass lock Sensor Data Code and/or password XXXXX the next ignition switch transition from OFF to CRANK.
Turn OFF the ignition, and wait 5 seconds .
Start the engine, the vehicle has now learned the password.
Category: Chevy
Satisfied Customers: 23917
Experience: ASE certified tech ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
AMEDEE and 7 other Chevy Specialists are ready to help you
Customer: replied 5 years ago.
I am glad you e-mailed back. I lost the page while I was clicking around and was not able to accept answer. You got me on the right track. I did the re-learn process but it happened again so I guess I need an ignition switch. Reading about this problem on the net many people are re-experiencing same problem after replacing ignition switch. Is there a way to by pass pass-lock security system?
Expert:  AMEDEE replied 5 years ago.

Thanks for the accept!

Unfortunately, no.. there is no way to by pass this security system. You will need to replace the ignition switch if you are are planning on fixing this problem the correct way.

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... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...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 L Rochester NY
< Previous | Next >
  • 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 L Rochester 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!!!! Alex Los 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. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, 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. Esther Woodstock, 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. Robin Elkton, Maryland

Meet The Experts:

  • GM Tech (Cam)

    GM Tech (Cam)

    Chevy Technician

    Satisfied Customers:

    GM Grand Master Technician 2007. 14 years experience.
< Last | Next >
  • GM Tech (Cam)'s Avatar

    GM Tech (Cam)

    Chevy Technician

    Satisfied Customers:

    GM Grand Master Technician 2007. 14 years experience.
  • Tim's Auto Repair's Avatar

    Tim's Auto Repair


    Satisfied Customers:

    Have owned a repair shop for 25 yrs.
  • Gary's Avatar


    Chevy Technician

    Satisfied Customers:

    15 years GM master tech
  • Dave Nova's Avatar

    Dave Nova

    Chevrolet Technician

    Satisfied Customers:

    ASE Master Certification. GM World Class Certification
  • John's Avatar


    Master A.S.E Automotive technician

    Satisfied Customers:

    A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
  • Don 'Mo Lurch''s Avatar

    Don 'Mo Lurch'

    Auto Mech / Electronics

    Satisfied Customers:

    Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.
  • Ron Z.'s Avatar

    Ron Z.

    - Chevy Tech -

    Satisfied Customers:

    18+yrs experience. State Inspector and Chevy Diagnostics