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 Pete Your Own Question
Pete
Pete, Technician
Category: Lexus
Satisfied Customers: 25402
Experience:  Over 17 years diagnosing and repairing automobiles various makes and models with some training and certifications.
14928985
Type Your Lexus Question Here...
Pete is online now
A new question is answered every 9 seconds

My vehicle will not start had the push button starter switch

Customer Question

My vehicle will not start had the push button starter switch replaced and it still will not start prior to the switch being replace there was no communication to the computer now there is communication but it still will not turn over
JA: Have you checked the battery, particularly the terminal connections? Are they corroded?
Customer: no replaced the battery as well and terminals are all good
JA: What is the model/year of your Lexus?
Customer: 2008 is250
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: I had a shop tell me it was the switch so i bought it my self and replaced it with the battery and still same thing
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 5 months ago.
Category: Lexus
Expert:  Pete replied 5 months ago.

My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

If you havent tried this yet,try locking and unlocking the doors with the remote or interior lock/unlock button and see if the vehicle then starts.In some cases this will work as I have seen on some models after the push button start button is replaced.If this does not work at all let me know.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Customer: replied 5 months ago.
I have done the lock and unlock thing already
Expert:  Pete replied 5 months ago.

Is there a fault code that was setting with this issue here that you know of?

Customer: replied 5 months ago.
There is a code U105
Expert:  Pete replied 5 months ago.

This code indicates a loss of communication with the electronic power steering system.This can lead to a faulty ECM (engine control computer).If the ecm is faulty it is causing this issue here.If you would like I can post the diagnostic procedure for this code set here for you to follow to help pinpoint and correct the fault or to have a shop or dealer diagnose it to locate and correct this fault just let me know if you want the info on this.

Let me know if you need anything else and feel free to rate my help here as this is how I receive credit for my time.Your 5 star rating is appreciated

Thanks Pete

Customer: replied 5 months ago.
if you could. And one more thing I forgot in the morning the check engine
Light will be on and the vehicle will turn over and not start before trying to start the car you can communicate with the computer after you try and start the car the check engine light will go off and no mo re e communication with the scan tool
Expert:  Pete replied 5 months ago.

This does sound like the ecm is at fault here.The ecm controls the check engine light.It should come on every time the key is switched on before you start the car.If it turns off and does not come on intermittently with the key on and the engine is not starting I suspect the ecm is at fault needing replaced.Below is the diagnostic procedure for this fault code you have set here.

DESCRIPTION

The power steering ECU assembly receives signals from the ECM, skid control ECU, and steering control ECU via CAN communication.

https://www.dropbox.com/s/m646xoxecy0m5y9/e-08-23.gif?dl=0

HINT:
- When two or more DTCs starting with "U" are output simultaneously, inspect the connectors and wire harness of each ECU.
- If the power steering ECU assembly detects DTC U0121 only, it adjusts the amount of power assistance for a speed of 100 km/h (62 mph) and continues system control.

INSPECTION PROCEDURE

PROCEDURE

1. CHECK WIRE HARNESS (+B1, +B, E)
(a)Turn the engine switch off.
(b)Disconnect the ECM connectors (E4) and (A5).

https://www.dropbox.com/s/lfh1j6y3kauvhtt/ec-08-23.gif?dl=0

(c)Measure the resistance according to the value(s) in the table below.
Standard resistance:

https://www.dropbox.com/s/ng8emdclta6dfzs/ecm-08-23.gif?dl=0

(d)Measure the voltage according to the value(s) in the table below.
Standard voltage:

https://www.dropbox.com/s/u6ej22aou5406oq/ecmm-08-23.gif?dl=0

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM

Let me know if you need anything else and feel free to rate my help here as this is how I receive credit for my time.Your 5 star rating is appreciated

Thanks Pete

Customer: replied 5 months ago.
Hey Pete, I have tryed replacing the ECM Now as before one attempt at starting it before you hold the brake to start vehicle has communication hold the brake check engine light goes off vehicle will turn over once and will not start after that no communication and will not communicate until you let it sit for a few hours not even if you disconnect the battery still no communication until it sits a few,hours
Expert:  Pete replied 5 months ago.

Did you follow the chart above to lead to replacing the ecm and was the ecm programmed?

Customer: replied 5 months ago.
to both and when the programer tryed to start the car the same problem happened
Expert:  Pete replied 5 months ago.

This is a difficult one for sure.

The only other thing I can think of is an issue with wiring leading to the ecm.