No start, no crank, no voltage to starter relay

Hi!

Have a 2006 Tacoma V6 automatic. Doesn't start, doesn't crank. Brand new fully charged battery w/ good ground. Fuses in cab good. Starter relay good (swapped with horn to check). 7.5A fuse (between 12+ and relay) good. No voltage across any of the 4 starter relay pins. I thought one of the 4 pins was always hot? 12+ to starter.

I'm about ready to swap out the NSS, but am surprised there wasn't 12V to the starter relay. Is there some alarm circuit stopping this? or does the circuit include the NSS?

Suggestions?

Danno

 

Power flows through the start contacts of the ignition switch to the start relay. One set of ignition contacts controls the hot to the relay coil through the neutral safety switch and the second set a ignition contacts controls the hot to the start relay contact. You won’t measure any voltage at the start relay coil or contacts without the ignition switch in the start position.

 

Read through this post it has a lot of good information.
https://www.tacomaworld.com/threads/05-x-runner-starting-issue-help.720076/page-2#post-25643300

Look at these prints they could help you find the issue:

The starter always has 12 VDC connected directly from the battery Large Black wire with Red Stripe.

The Yellow with a green stripe wire goes to the starter solenoid coil and comes from the starter relay when the ignition key is turned to the start position.

None of the starter relay pins have power ALL the time.

 

This has happened to me a couple of times over the years. One of them was just now. I think it's something in the ignition switch but I'm really confused. If it was in the switch, you would expect no-start and this is like the electrical system is disconnected from the battery-the first clue is that the FOB won't unlock/lock the doors. Key-on acts like no battery/dead battery. Move the wheel and turn the key again and all good. Truck runs like shit for a time-that's the result of the "disconnect" which is how I believe it is something that disconnects the battery from the ECU. The ECU resets and it will take a few miles of driving to recover any adaptations it does.

 

Thanks for the replies, guys. I'll see what I can do with this new info.

Also, I forgot to give some possibly important history. I bought this pickup only a few weeks ago. The used car drove it from the back part of the lot to the front, turned it off and I inspected it. But when I went to start it, it wouldn't crank. Just like the current problem (no pun intended). There was also some difficulty with the button next to the shifter covered by a plastic panel the size of my fingertip. Had to remove it and depress it, which also (or only?) allowed it to be shifted out of park.

I only found out later that the key would only work in the ignition but not unlock the doors. I took it to the Toyota dealership prepared to pay $200 for a new transponder key. They cut the key but it still wouldn't unlock the door. This was just a regular metal key. They said the door locks had been changed.

Cheers,
Dan

 

This could be the brake stop-light switch-it's also used as part of the interlock to prevent you from shifting into gear unless your foot is on the brake. $20 will get you the switch and a few minutes of wriggling around behind the brake pedal assembly will have it replaced.

 

Wow! A few days ago I bought a OBD reader and the only error code was for a brake light something. I'll have to check that out. Thanks!

 

Update: Replaced the brake light switch. Nothing changed. No crank. But the switch WAS bad so now, if I ever get going, people will know I'm braking, hehe!

Jumped the copper leads of the starter relay, those on the left in the pic of the relay. Turned the ignition to start, and nothing. According to the upper diagram the Jimmyh posted, if the starter relay was blocked by the engine control model or anything else, it should have cranked. So haven't I ruled out a problem with the NSS? I also have read about some immobilizer circuit. Was hopeful cuz I had replaced the old battery that would die after several hours being turned off. Did the 5 quick on/off turns but still nothing to potentially disable the disabler, but nothing.

There is no click going to the start position, but there is some humming up front.

I supposed I could make sure I'm getting a signal through the ignition switch. Only thing else would be the starter itself, right?

Also, what is the purpose of the button under the 1/2 inch by 1/2 inch plastic cover next to the gear shifter? Is it only to keep the shifter from moving out of park? The seller opened it up, jammed something down into it to depress it permanently so it can move out of park. How is it supposed to work normally?

 

I’m not saying this will work, but it’s free. Lock the doors, use the key to unlock the drivers door, then try to start it.

 

The hole in the shifter console allows you to release the shifter out of park when you don't have a functioning stoplight switch

If you don't have power to the starter solenoid on yellow/green wire when cranking then go back to the START relay and do some testing with a DMM. Everything you need is in the wiring diagram jimmy posted

 

You need to find out if you have power to pin 5 WHEN CRANKING. -Start here

If you do, and jumping pins 3 and 5 at the relay does nothing, the problem is likely at or between the starter.

If you don’t have power to pin 5 while cranking, then the problem is between the ignition switch, the ignition switch, or between the battery and ignition switch.

This is only testing the feed side of the relay, which should get the truck cranking.

The control side is being by-passed when jumping the pins at the relay.

 

This. The brake light switch also serves as the interlock switch. Take what ever was/is jammed in there out and put the cover on.
I’m not 100% sure, but something also prevents you from starting in gear.

 

That would be the Park, Neutral Safety Switch. It only allows the truck to start while in Park or neutral positions on the shifter.

So if he has an issue with the Park, Neutral Safety Switch it would never energize the Starter Relay...

** It is all in the circuits posted above.

 

Thanks again for the suggestions.

Replies
Can´t unlock the doors with the key. Asked Toyota to make a new one. They cut one from the VIN but it didn´t work in the door. I didn't think to ask them if it would work in the ignition. I know a transponder key is needed to start, but I could tell from the dumb key if it wouldn´t work in the ignition, right?

The battery operated fob or whatever also doesn´t work. I haven't tackled that problem yet. New 2032 battery.

My plan is to get the transponder key and have a locksmith adjust the door lock cylinder to matchup. It would be nice to have two sets of transponder key, one hidden on the frame for backup. But at $200 per key, that's pricey.

Hole near shifter. Yup. Now that I've replace the brake light switch, I don't have to use it. Used car dealer was ignorant, dishonest, or both.

New Info
There is 12+v between pins 3 and 5 when trying to crank. I then monitored the other part of the relay. 8.6 when in the ON position, 11.8 in the START position. Is this normal?

Assuming the power to the starter relay is normal, doesn't this mean there's a problem in the line to the starter solenoid or in the solenoid itself? If so, it seems unlikely that it would be in the wire to the solenoid and I don't know how I could easily check that.

What's next?

Thanks,
Danno

 

What’s “the other part of the relay”? Pin 1 or 2?

Next step would be to check connector EB1 pin 6 and apply +12V to it, half splitting the circuit to determine why the starter isn’t getting voltage.

 

Sorry. Wasn't measuring the voltage at the relay correctly. Pins 1 and 5 have 11.8V when in crank position. I just now also measured the voltage between pos and neg battery terminals. 12.06. Was 12.6 a few days ago when I started all this. Brand new battery. Never have left the ignition on. Only been testing for a few seconds at a time. Isn't this a rather high drop over such a short period?

A few days ago I checked the hot lead to the starter and got 12v. Just now I checked that there is 12v to the signal line of the starter when in crank position, so EB1 must be fine. And the starter case is grounded. Seems to me everything is normal going to the starter so it has to be in the starter itself.

 

rap on it a few times with a brass mallet. Sounds like your signal wire to the starter is getting there fine. Check the positive lead to the starter motor (the big cable) that originates from the battery for tightness and no corrosion. Measure the voltage at the starter motor when attempting to crank, you should expect almost the same as battery terminal voltage, no more than a 1/2-3/4 volt drop. If all is well there id replace the starter.


As for why your battery is down to 12 volts, it could be a number of things but probably just due to lack of running it. Put the battery on a load tester then trickle charge it back to full capacity before trying to start the truck again.

 

Sounds like you need a starter

Don't worry too much about the small drop in voltage at the battery. Once you get a good starter in there, the real test of the battery health will be seeing if it drops below 10 volts during extended cranking. If it drops below 10 V it's weak, if it stays above 10V its strong

 

I’ll go ahead and say. Buy an OEM or OEM Reman.
Or if you feel like trying to save a few dollars?
https://www.tacomaworld.com/threads/starter-issue.642280/#post-22214503

Here is a How To. - Some guys claim to have gotten the starter out with out removing anything.


https://www.tacomaworld.com/threads/changed-my-starter-today-removal-tips.720779/#post-25659984



https://youtu.be/MYmlLKz_yoA

 

Thanks guys.

But even if it starts after I rap it, wouldn't it still be best to replace the starter? That's what my ex did with me. Worked for awhile, but she's much happier with the replacement she got 6 therapists later. And a few days ago there was no voltage drop from the + post down an inch across those connections. Voltage was 12 something at the starter, so there was less than 1V drop. I'll order order a starter from Amazon. If for some reason it doesn't work, I can return it. But since I'm gonna take out the old one anyway, could prolly bench test it while waiting.

Any ideas about my key issues? Should prolly start a new thread for that.

Cheers,
Danno