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Starting issues with 2003 RX300

 
Old 03-05-19, 12:25 PM
  #16  
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True, looking forward to your updates.
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Old 03-13-19, 07:08 PM
  #17  
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Hi all,

Just wanted to give a general update
since last time when the issue fixed itself, it has not come back yet. I did not do any additional work other than what I explained a few weeks back on this forum.
Thanks again to everyone how helped and gave me suggestions. I will let you know if anything changes

Thanks
Asghar
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Old 03-17-19, 02:09 PM
  #18  
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Hi all,

The issue just came back, now it is not starting when getting a jump from another vehicle either, it kind of seems like the crank sensor. It started back on once the car cooled down
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Old 03-17-19, 02:56 PM
  #19  
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Originally Posted by Nad1370 View Post
^^^
I'm inline with Salim and i think i know where he's getting at.

No spark as you say when cranking.
Each ign. coil needs power and ground to energized.

Igniter (coil) power check
--- Disconnect 1 ign coil connector (any accessible one)
--- Key ON posistion
--- White wire w/ a RED tracer should have POWER

Now for ground check for the igniter (coil)
Each coil shares the same ground.
--- Key OFF
--- Same connector
--- White wire w/ BLACK tracer
--- Should have continuity to ground

Let me know what your results are.
^^^
Were you able to do these checks?
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Old 03-17-19, 09:35 PM
  #20  
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Read the following article on a bad crank sensor and what causes them to go bad.

​​​​​​https://scanneranswers.com/diagnosin...sition-sensor/

This is what a working crank signal (ckp) look like

Last edited by Audiqv8; 03-18-19 at 09:55 AM.
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Old 03-18-19, 04:57 PM
  #21  
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Nad1370, I am waiting on a multimeter to measure that

A new finding, I tried connecting 2 different OBDII readers and both said they can't connect to the vehicle. this was when the car wouldn't start. does this mean anything

Audiqv8, Thank you for the link, I will read it now
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Old 03-20-19, 03:21 PM
  #22  
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Originally Posted by asghar101 View Post
A new finding, I tried connecting 2 different OBDII readers and both said they can't connect to the vehicle. this was when the car wouldn't start. does this mean
Check your 7.5amp OBD fuse



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Old 03-21-19, 05:55 AM
  #23  
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Originally Posted by asghar101 View Post

A new finding, I tried connecting 2 different OBDII readers and both said they can't connect to the vehicle. this was when the car wouldn't start. does this mean anything
Was the key in the 'ON" position when you connect the OBDII? Did the OBDII work when the car started?
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Old 03-21-19, 11:01 AM
  #24  
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All the indications are of a bad ground.

Salim
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Old 03-22-19, 04:57 PM
  #25  
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so I tested the wires you mentioned when the issue exists I do not see any power from the white-red, though the white-black shows 0 across to the car's body and the body seems to be connected to ground fine. Also when the issue is present the OBDII sensor turns on when connected but then it says can not communicate to the vehicle.
Yesterday, I tried to start the car and it started just fine and hasn't had any issues in starting back up again, now the OBDII can connect and communicate and it does not show any errors, however, the status light on the OBDII is yellow

I am at lost and no matter which mechanic I take it to or talk to, doesnt know what the issue could be, some suggest crank sensor but the vehicle doesnt show any other sign of a bad crank sensor and the OBDII doesnt show anything. one mechanic suggested that it could be the ECU of the car, what do you guys think?

Thanks
Asghar
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Old 03-23-19, 05:57 AM
  #26  
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It's tough when it's an intermittent issue. Especially when you can't communicate with the computer when the issue is present. That doesn't make sense. It's got to be a ground issue. Obviously not a blown fuse issue, it wouldn't work some of the time. And it's not what my issue was, the IAC clean worked for me, but loss of obd2 com means something else entirely. Do you have an aftermarket alarm installed?
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Old 03-25-19, 09:34 AM
  #27  
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Originally Posted by salimshah View Post
Loose connection is the only probable cause. Other issues generally don't fix themselves up.

Was any work done which may left a ground not secured to its post?

Salim
I had a similar issue with my VW Scirocco may years ago. May be a total red herring but it ended up being a bad connection in one of the engine wiring harness connections. The car had just been to the local smog inspection station and I guess they tapped into this harness to take some measurements and didn't put it back together tighly. Took the VW dealer shop foreman 2 days to find it!
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Old 03-31-19, 10:01 PM
  #28  
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Originally Posted by asghar101 View Post
so I tested the wires you mentioned when the issue exists I do not see any power from the white-red, though the white-black shows 0 across to the car's body and the body seems to be connected to ground fine. Also when the issue is present the OBDII sensor turns on when connected but then it says can not communicate to the vehicle.
Yesterday, I tried to start the car and it started just fine and hasn't had any issues in starting back up again, now the OBDII can connect and communicate and it does not show any errors, however, the status light on the OBDII is yellow

I am at lost and no matter which mechanic I take it to or talk to, doesnt know what the issue could be, some suggest crank sensor but the vehicle doesnt show any other sign of a bad crank sensor and the OBDII doesnt show anything. one mechanic suggested that it could be the ECU of the car, what do you guys think?

Thanks
Asghar
Thanks for the checks.
Im assuming you did the power checks with the KEY in the "ON" position.

If you are missing power at the White/Red wire, your coils are not energized.
Power flow goes:
Engine room Junction block --> IGN switch --> Instrument panel Junction block --> Ignition coils
Somewhere along these lines is your problem.
Assuming you do have ground on the coil connector and immobilizer light is off when key is in the ignition.

This is what i would do.
Since you are missing that power wire to energize the coils, i would splice straight battery power to the WHITE/ RED tracer wire on any ignition coil.
You wont hurt anything since it suppose to get power there anyways.
(Some remote start companies wire it this way)
Try this out when your issue is present and see if it does start the vehicle.
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