Toyota Tundra No Start with No ECM Communication

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Matthew.Myers5

Guest
Has anyone found the fix for this. I have crank but no start, 4 lo flashing, and no communication to the ECU. It has done this a couple times in the past year, let it sit awhile and starts right up and will be fine for awhile. Just looking to see what direction
 
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laarrin

Guest
Has anyone found the fix for this. I have crank but no start, 4 lo flashing, and no communication to the ECU. It has done this a couple times in the past year, let it sit awhile and starts right up and will be fine for awhile. Just looking to see what direction
I have same issue have you found anything
 
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Brian

Guest
I now have this issue. It is blinking 4Lo and 4hi back and forth, no link with ECM, it died while backing out of my driveway. Crank all day no start. Really need some ideas!!!
 
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Rob g

Guest
That's why we're here Greg. Thanks for working on Toyota's.
Hey guys I have a 2008 Toyota tundra 4.7 and I was driving down the road everything was fine and my 4lo light came on my truck stalled and now it won't start it will crank but won't start when im trying to start it the engine light is flashing and my cousin has a snap on computer and when it start scanning systems it get to the forth system and kicks him out iam stumped on what to do i work on my own stuff so trying to diagnose any help would be very much appreciated
 
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Brian

Guest
It sounds like several people are having this issue. I found that one of my connections to one of my air pump drivers had a melted circuit in the connection plug. Still no ECM communication, locked in park, 4hi and 4lo flashing. Help!
 
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Xavier

Guest
Hi, i have the same issue with my 2007 Toyota Tundra 4.7l 4x4.
Iam working on it for 9 months now ... it goes to my Toyota dealer and they didnt found nothing except the ecu was not communicate with obd2 ....
After a lot of test and recherche.... the Toyota system work with 5v sensors and if you have one of them shorting it turn the ecu in lip mode and give you no communication to ecu.
To find the problem, you have no choice, try to unplug the sensor one by one and try to scan after each one.... ALL TOYOTA SENSOR WORK WITH 5V
Most view is :
power steering pressure sensor
Air injection pump (you got 2 of them)
Crank sensor
Cam sensor ( x2 one inside the timing cover one outside)
Fuel gage
Knock sensor
Etc......
This is a Toyota's problem sins they put a computer in there car ... not just in the Tundra but all Toyota can have the same issue .
I hope it help someone
Sorry for my english iam french
 
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Brad

Guest
I just changed my motor in my 2006 tundra 4.7L from another 2006 tundra with half the mileage,installed fresh battery, but I have no power at all going to my dash or key. Would anyone have any ideas?
 
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JCL3623

Guest
Finally got my Tundra figured out after almost a year of messing with it. Had all the problems you guys have listed already. Long story short, there's air switching valves at the rear of the intake that had shorted out. I had the dealer do the work for me and it cost me about $850 to replace, and now I'm up and running again. Hope this helps!
 
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Kelly

Guest
If you run across a 2008 Toyota Tundra (3UR-FE) and have a no start, no ECM communication condition and there is no "Check Engine Light" bulb illuminated during the function check, disconnect the secondary air valves.These have a tendency to short the 5 volt reference line and stop all ECM communication.
My 08 quit going down the road after checking I had no fire no fuel and scanner wouldn’t communicate. The air valve on driver side had went bad when I disconnected it my commutations started working Replaced valves and back rolling. Thank you for sharing
 
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One Kay

Guest
Thanks guys for the tips. I got my wire harness messed up then the next thing I know, it wont start. 4LO light keep blinking.

Upon checking with obd2 tools, no communication to ecu.
What I did was change my ECU, rewrite new VIN on it so that it match my car. Then perform reset on ecu, jump pin 4 and 13 I think.

It start straight away.
 
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Mohammed

Guest
Im having problem with my toyota seqouia 2012
Check engine light blinking and the car wont start.
No ecm communication
 
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Adam McLaughlin

Guest
I had all the same issues changed alot of things then I unplugged the air injection pumps it's been running so far check engine light is finally on and it runs before it would run good one day and when it rained no start so I'm hoping leaving them unplugged works?
 
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Adam McLaughlin

Guest
Bought new fuel pump ecu crank position sensor cleaned throttle body and mass air flow sensor. Battery is good checked all relays and fuses I've heard the valves and secondary air pumps just don't last best thing I'd do is get both bypass kits but question is will it cause more serious issues if I just run it with the secondary injection unplugged? Truck is a 08 with 208000 just want a few more years outa it
 
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Glen

Guest
Bought new fuel pump ecu crank position sensor cleaned throttle body and mass air flow sensor. Battery is good checked all relays and fuses I've heard the valves and secondary air pumps just don't last best thing I'd do is get both bypass kits but question is will it cause more serious issues if I just run it with the secondary injection unplugged? Truck is a 08 with 208000 just want a few more years outa it
 
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