2005 Tundra - intermittent starter engagement

Hello guys! First time poster.

My tundra has been a great truck but I have hit an interesting problem maybe someone can help with. The truck has about 150k miles on it.

This all started one day when I tried to start it and the starter would not turn over or click just nothing at all. I took it too a great independent mechanic and he confirmed the starter was bad and put a new one in.

Now about 1 in 15 times when you turn the key you get the same problem, no starter, no crank, just nothing.

But if you jump the relay with the key in the 'on' position, the trunk will crank but will not fire. But if someone holds the key in the 'crank' position and then you jump the relay the truck will start. This will repeat the cycle, after this it will start normally with the key again about 1 in 15 times. When it happens again I repeat the steps above of jumping the relay while the ignition is in the 'crank' position. I have tried about 3 different starter relays with the same result.

Any advice on where to look would be greatly appreciated

 

Chances are the original problem was not the starter. I hope the mechanic at least replaced with another Denso starter.

Can you please tell us what cab type, as that's pretty critical on this one.

Did the truck come with a dealer add-on alarm which you're seeing under the dash, SECURIKEY+ or KARR? Have you checked under the dash, do you have a non-standard key fob, etc?

Do you have a different key you can try, as some members here have found old keys (including the few double cabs w/immobilizer keys) can cause finicky stuff with the switch?

Have you had the battery professionally tested for CCA? (any auto parts store will do for free)

Have you checked the grounds and power cables for corrosion inside the cables within the last inch or so before the terminal?

 

Thanks for the reply. It is a SR5 Extended cab

The key and key fob are the factory toyota. It does not have a dealer or aftermarket alarm system.

I have not tried my spare key when this happens but will give it a shot.

The vehicle did have an interlock system on it that was removed about two years ago. Underneath the dash there are about 3 crimp connections left from this but they appear to be very tight and in good shape with no corrosion. Have had no problems with the starting until about 3 weeks ago.

The battery was replaced about a month ago and does test good. When you jump the relay the engine cranks strong. It also cranks strong with the key when the key works. Have not checked battery cables for corrosion inside but do not think that would be the issue because of the strong crank when the key does work.

 

Totally makes sense.

I think it’s normal turnover won’t happen unless the key is in crank position while jumping the relay.

I’m digging in my brain on this one because I feel like similar symptoms were seen from someone else recently. I feel like @BubbaW hopped in with some poignant ideas. I feel like it was something under the hood and nothing to do with PNSS or similar, or maybe I’m remembering backwards. Let me tag him with that and see if it’s triggering any thoughts.

 

05 should be bump to start on the ignition switch. The ecu sends the actual crank signal to the starter.

Maybe a failing ign sw. Can you momentary jump the start wire?

 

Have to ask given some use "Extended cab" wrongly at times. Is that meaning "Double Cab" and if so, is your MY an 04 or 05/06 ?

Wiring colors, junction points are different between 04 vs 05/06. It matters given it appears from all your good troubleshooting that the starter relay is not receiving the "STAR" signal from the ECM each and every time.

IMHO, you'll need to monitor at least the 3 locations behind glove box circled in red in below pic when you have no "click just nothing at all" to determine where the loss of the STAR signal is. Since you "tried about 3 different starter relays", see no need to check at pin 1 of starter relay.

Once we have what MY and clarify you have a DC, pin locations/colors can be provided.

 

This will be interesting... I have the exact same issue with my 02 Celica... problem is no one has really come up with a solution over there, besides people being called out for using non-Denso parts.. Well, this one is all stock, but still has the issue, I carry 2 short wires and 2 long flatheads just incase the wires grow legs... Will follow this guide as well and see if I can solve it on that end.

 

Or as I like to ask, "You obviously have a 4dr ... do all the doors open the same direction?"

 

Thank you for the replies. It is a 2005 Extended cab, the back doors don't open unless you open the front.

Thanks BubbaW for the input I was not aware of this circuit

 

Toyota refers to that cab configuration as “Access cab” or AC. The regular cab is RC and the full 4 door is the “double cab” or DC. These names only apply to First Gens 2000-2006. The next gen tundras then jumbled all the names up again and these don’t apply the same way 2007 and after.

 

Now the truck won't start at all, was trouble free for about 3 weeks. Turning the key does nothing. When you jump the starter relay it will crank but will not start with the key in the "on" or the "crank" position.

I am thinking about going ahead and replacing the ignition switch. I am not sure how to diagnose it. Any other ideas?

 

If your access cab is same as that diagram provided by Bubba, you may consider testing the park/neutral position switch. I haven't personally been in there but I would guess that there is some sort of mechanical component to this given our column shifter does wear - where the rest of this looks like it maybe harness based and fixed in position (less likely to wear).

Maybe check for continuity for that specific P1 connector (the white/black going into it) before throwing a new ign switch at it.

 

@snowcone5280 @BubbaW

Hey was this ever resolved? My truck is doing the same thing. Wondering if I should replace the ignition switch or the ECM or burn it to the ground

 

At -40 deg you mentioned in the thread you started yesterday, I'd definitely burn something down or wait till spring
Unfortunately the thread starter of this thread did not come back and update.

 

... and was last seen in fall 2023:

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Dang! At this point I’m about to burn something down alright.