Toyota Tundra No Start with No ECM Communication

Lewis

Moderator
Staff member
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.
 
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Greg Turner

Guest
2007 Tundra 4.7 air injection check valve was the cause of no communication with scanner, no start. Thanks

GT
 

Abhor

New Member
Having same issue. Truck died at a stop light as I took my foot off the break to drive away and the 4LO light started blinking. Engine turns over but won't start. No check engine light at all, even in the "ON" test position. Can not connect to ECU, even Toyota can't connect. It has been at the Toyota dealer for two week now and they still don't know what the issue is. They had a new ECU ready to install but they tech decided to test it first and it did not work either.
 
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Mark O

Guest
Having the same issue with my 2012 tundra. Any luck with the dealer resolving that issue.
 

Abhor

New Member
No luck!!! Has been at the dealer this entire time. They are thinking they will need to replace the engine wiring harness.
 
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nap

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.
Can we go ahead and diagnose the truck?
 
S

Sherwin

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.

Is there a way to correct this without replacing the valve?
 
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Johann

Guest
I replaced the secondary air valve and no problems for two months, yesterday my truck stalled while driving.
The tech said he could not communicate with the ecc, so I assume I have the problem with the 5 volt reference, but since it is a new secondary valve, do yo think it is a defective valve ?
 
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John usnr

Guest
Tried the air valve disconnect did not resolve issue with no communications and no start wwhawwhat else can I try?
 
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Nemo

Guest
Having same issue. Truck died at a stop light as I took my foot off the break to drive away and the 4LO light started blinking. Engine turns over but won't start. No check engine light at all, even in the "ON" test position. Can not connect to ECU, even Toyota can't connect. It has been at the Toyota dealer for two week now and they still don't know what the issue is. They had a new ECU ready to install but they tech decided to test it first and it did not work either.
 
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Adam Davis

Guest
Hoping someone has some thoughts. Mine died after going over a RR track, towed to Toyota. They wanted $2200 to replace my entire Sais system. Their notes say, no ecm communication, unless right bank air valve is unplugged. I drove it home in limp mode with trac, vcs and engine light on. Bought a bypass for sais, didn't work. Then we had someone disable the air pump system from my ecu completely. Put the ecu back in today and truck still would not start. I unplugged right bank air valve again and was able to read a code, pops up p0020 camshaft position sensor open circuit bank 2 and p0553 power steering pressure/ switch circuit high input. Yet no communication and no start with air valve plugged in? I am at a loss.
 
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Louis

Guest
I am having the same issue. I change my air pump. Then whas going go for one day. Then it would start again. Ecm not responding no check engine on. I got the 4 low blinking and traction control off.
I change the computer not better.
Then I change the main harnest. Because had no 5 volt. This is all what the dealer Toyoya told me.
My truck is still not running. Crank but don’t start and don’t hear the fuel pump.

Toyota Tundra 2010 5.7
 
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Tcdavis

Guest
Did you ever find the fix? Mine is still crank, no start. I've bought OEM valves and a new (used) ecu

I am having the same issue. I change my air pump. Then whas going go for one day. Then it would start again. Ecm not responding no check engine on. I got the 4 low blinking and traction control off.
I change the computer not better.
Then I change the main harnest. Because had no 5 volt. This is all what the dealer Toyoya told me.
My truck is still not running. Crank but don’t start and don’t hear the fuel pump.

Toyota Tundra 2010 5.7
 
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