ShawneeCreek HalfDork
7/6/19 11:59 a.m.

I'm running out of ideas and need some help from you guys. Details first:

  • 2004 Toyota Tundra
  • Double Cab
  • V8 engine (2UZ-FE)
  • Automatic transmission
  • 4wd
  • Originally a southern truck, so no body rust and very little surface rust on frame.

First issue: No-Start

Turn the key to start and the engine doesn't turn over. The truck did this all of a sudden. It hasn't exhibited any intermittent issues beforehand.

Things we've tried:

  • Battery voltage is good, 12+ volts. Battery is less than a year old. Terminals cleaned.
  • All fuses in engine bay and under dashboard removed, checked out ok, and replaced.
  • Battery ground cleaned.
  • Starter relay tests good.
  • Jumper starter relay terminals with the key in "Run" and the truck turns over and starts, so the starter is good.
  • Not getting a 12V signal to the control side of the starter relay during start. Ground pin on signal side of relay checks out ok.
  • Neutral Safety / Gear Position Switch replaced and tested good (both new and old parts).
  • Getting 12V signal to the NSS during start. This indicates that the ignition switch is also ok.
  • According to the wiring diagrams online the Starter signal also travels though the main Engine Control Unit (ECU) and the Toyota Vehicle Intrusion Protection (TVIP) ECU.
  • Pulled the ECU out and disassembled it. Did not see any evidence of smoke escaping components. Reassembled it and put it back in the truck.
  • All wiring looks good. No evidence of rodents, corrosion, or chaffing. 

We haven't checked the TVIP yet. I'm not sure what I would check anyways.

Second issue: Stalling when shifting

If we jump start the truck with the screwdriver trick mentioned above and then shift into Neutral (whether from Drive or Reverse) the truck stalls and dies. It then displays the check engine light for two error codes: Camshaft position sensor and crankshaft position sensor. I'm at a loss for what is causing this.

One other concern that may be related, there is now a current drain on the battery when it is parked. Big enough to drain the battery overnight. We haven't yet tracked it down.

What could be causing this? What should I look into next? Replacement ECU? TVIP system? Wiring? Battery? We've already put $240 into it for the NSS. Any ideas would be appreciated. I'm at a loss. 



Ransom PowerDork
7/6/19 1:16 p.m.

Pull fuses to at least get a rough idea of where the drain is, and whether it may be one of the suspect components?

I don't have a strong feeling, but it'd sure be easier to replace a big-ticket item if it was also spilling electrons all over the floor...

And it certainly wouldn't hurt to have the battery tested. I know it's relatively new, but stuff happens. Er... Have you verified that there's a drain you can measure? Or is the battery just dying overnight?

dj06482 UltraDork
7/6/19 7:21 p.m.

Check the battery cables themselves. I had one go bad and it was causing intermittent no-start conditions.

MrChaos Dork
7/6/19 7:38 p.m.

Have you checked if the keys are being recognized by the imobilizer? Like i know on my Land Cruiser the security light blinks a certain way if the master key is in the ignition.

ShawneeCreek HalfDork
7/6/19 8:02 p.m.

We just checked the battery again. It load tested fine to it's capacity and was at 12.5 V. And with the truck turned off there was less than a miliamp of current, so I'm not sure where current drain might be. We're leaving the battery disconnected overnight to see if it's draining itself.

We'll look the battery cables over, but I don't think that's the issue. We can get it started and running by jumping the contacts at the starter relay.

The keys on this truck don't have chips in them. The security was built into the lock remotes instead. Good idea though.

I'm going to stop by a pick your part junk yard on my way through Toledo tomorrow. Their website lists a semi-equivalent Tundra in inventory. I've got the part number off of our ECU to see if it matches. It's all of 7 Phillips screws to remove and only $42, versus $70 or more online. At that price, it's worth a shot.

irish44j MegaDork
7/6/19 8:07 p.m.
ShawneeCreek said:


The keys on this truck don't have chips in them. The security was built into the lock remotes instead. Good idea though.

That's interesting. I wonder if that changed in 05. Mine is a Sequioa, but mechanically identical to the Tundra, and mine has the chip in the key itself. In fact, I only have one remote and often use my 2nd set of keys with no remote present at all. 

Dr. Hess
Dr. Hess MegaDork
7/6/19 8:19 p.m.

On my 98 land cruiser, it will crank but not start if the immobilizer doesn't recognize the key.  Ask me how I know.  That is built into the ECU and not separate, as your's appears to be. 

I suggest clearing all the codes with either a battery disconnect/reconnect or using a reader.  Then put a key in, try to crank it, turn it off, read the codes.

It does sound like the security thingie to me, if that controls the starter too.

MrChaos Dork
7/6/19 9:30 p.m.

looking it up, 05 tundras have chipped keys. Note the flashing light next to the air bag indicator. That's the factory immobilizer showing it's active. If you have the flashing car light with the key in the middle of it then yes you have the immobilizer.

also this is your symtoms right?

Ransom PowerDork
7/6/19 10:51 p.m.

Sounds like a lot pointing to security, but...

If the draw is one milliamp and the battery is dead in the morning, that doesn't say anything good about the battery.

OHSCrifle SuperDork
7/6/19 11:17 p.m.

I believe that only some (I believe Limited) models have “chipped” keys. My 06 SR5 Tundra key definitely wasn’t chipped, since it was all metal and cut at Home Depot. Sorry I can’t add anything helpful. 

TGMF Reader
7/7/19 6:44 p.m.

I see you mention checking battery ground connection, but have you checked the ground straps from the engine block and trans housing to the body/frame?   They often break off. Seen some interesting stuff happen as a result.

ShawneeCreek HalfDork
7/7/19 8:26 p.m.

Ok, finally made it back home after the long weekend with family. The truck had to be left at my grandparents' home, so we won't be able to get back to it until next weekend.

To respond to the comments above, the issue isn't lots of cranking with no starting, it's that we don't get any cranking at all (unless we jump it at the starter relay). And this truck is an SR5, not a Limited trim level, so I don't think it got the full security system with glass breakage sensors and everything. There isn't a flashing security light on the instrument cluster or dashboard. But it does have remotes to lock/unlock/panic mode which makes me think it still has some form of the TVIP system. The key is just steel and has successfully run the truck before without the remotes present.

I didn't have any luck with the ECU at the junkyard. While the junkyard truck was an SR5, V8, 4x4; it was a 2000 extended cab and the ECU part number and connectors were different.

We'll do some more research this week and try again this weekend, hopefully. Currently the list of things to check are:

  • battery voltage, did it drop on it's own?
  • all ground wires, specifically the ones from the engine and transmission to the frame. One of the wires may be broken or frayed and/or corroded connections
  • bypass TVIP (security / door lock system) for the starter circuit

Thanks for all of your suggestions. Feel free to throw out any more of they come to you. We'll get this truck running again eventually.


MrChaos Dork
7/7/19 9:07 p.m.

Does it have an aftermarket alarm system in it? cause that might be causing the problem as well, I guess that is the same as bypassing the TVIP system though. Your symptoms scream alarm system/immobilizer issues to me. Phantom power draw, nothing to the starter when turning the key, engine dies when shifting to non d or r.

looking at the specs for the 04 SR5 v8. Security system is Optional, Panic Alarm is Standard, Immobilizer is Optional, Keyless entry is Standard.

also just in case for an fyi.

whats the mileage on the truck? because I know UZ starters go at around 180-200k. My Land Cruiser has some odd starting behavior at times but the starter thats in it has 250k miles on it.  Its not the starter itself that goes bad its the magnetic switches inside the starter that go bad which causes the starter to not start/start occasionally/act weird.

ShawneeCreek (Forum Supporter)
ShawneeCreek (Forum Supporter) HalfDork
7/27/20 11:33 a.m.

A year later and we finally fixed this truck. I visited my family over the 4th of July weekend and worked with my Dad troubleshooting. We tried cleaning grounds again: no change. We stared at wiring diagrams and traced wires and voltages around the starting circuits. Finally we ran a jumper wire from the starter relay in the engine bay fuse box to a junction connector behind the glovebox. Magically the truck started normally and even stayed running while shifting the transmission. Unfortunately, the wires that connect those two points are buried behind the dashboard and were not worth the effort to trace further. We decided to run a more permanent, cleanly routed jumper wire and started to pull the fuse box to make a nice connection there to the backside of the starter relay.

And that's when we found the real problem. I cracked open the fuse box and discovered a wire connected to nothing. And wouldn't you know it, it was the exact color of the wire that we needed to connect to. Once I got the entire cover off the back of the fuse box I found a number of other wires with missing insulation. It turns out that a field mouse had crawled up inside the back of the fusebox and had chewed on the insulation (mostly the white wires, interestingly) and had eaten completely through the starter relay signal wire. We reconnected that wire and I wrapped electrical tape around all the wires with missing insulation. Slap the fusebox back together with some steel wool and tape over the holes and we were done. And that fixed all of the issues, including the phantom battery drain.

So lesson learned: weird electrical issues, look for evidence of mice, including inside the fuse box. Stupid mice.

Recon1342 Dork
7/27/20 5:28 p.m.

In reply to ShawneeCreek (Forum Supporter) :

Yup, that'll do it...

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