Tricky no-Start issue 06 DC

Thanks in advanced for any help! - I am Located in Alberta, Canada

All these issues seemed to arise right after completing a timing belt job on my truck, it may be correlated, but also may be a coincidence.

On occasion there is a no start, but still cranks. Issue seem to go away after a while and will eventually start. I noticed this happen once a few days before completing the timing belt, but after one failed crank it fired right up. After the timing belt the issue is more severe, leaving me almost stranded a few times.

When truck is turned off the HVAC system and Headlights will stay on, sometimes both, sometimes just one or the other, the hvac will stay off if the dial is turned to off. To turn the headlights off you must pull the relay, then they stay off once the relay is reinstalled. Audible electrical sounds under hood when the headlights were stuck on.

The car alarm will sound at random when the truck has been sitting (locked) for quite some time, unlock/lock with fob will temporarily stop the alarm, but will start back in a few seconds.

I Checked the connectors under the right-side passenger kick panel, since my friend found a bulletin explaining that is a common issue. I found some corrosion on two of the connectors, cleaned them up, applied some dielectric grease and reconnected, the issue persisted.

I noticed the truck was not charging at idle, after a short drive it seemed to be charging normally again, Maybe this is just a coincidence?

Scanner was only sometimes able to connect to BCM, ABS and airbag systems.


Recorded codes:

P0051 Oxygen sensor (A/F) Heater Control Circuit Low (B2S1) (known issue before T-Belt)

P0504 Brake Switch “A”/”B” Correlation

B2799 Engine Immobilizer System

 

I originally replied with some content in your other post:

Sounds like something probably arc'ed out, OR someone has water intrustion into the fusebox, which is a really well-known issue covered in the megathread. Specifically:

• These trucks usually don't have a ton of other electrical issues. Hidden corrosion inside the battery/alt cables happens. Sometimes, a couple thousand miles after timing belt changes, people will have startup issues because the crank position sensor wasn't properly tucked away and gets rubbed by a belt (pic). There's also a similar problem with camshaft position sensor under the cam cover, where the belt will rub through (pics). There's the rodent issues mentioned earlier. Occasionally, water leaks can send water down into the ECM behind the glovebox (pics), or into the fusebox inside the cab/dash (pics and more pics). A lot of drain/vampire issues trace back to aftermarket add-ons whether the owner knows they exist or not - alarms as mentioned earlier, brake controllers, poorly installed trailer receptacles, those are some big ones.

But something as simple as arc'ing at the main fuse where the feed from the battery goes into the engine bay relay box could probably cause some weird issues too. If there's a relay between that engine bay fuse/relay box and the feed coming into the cab, I'd be eyeballing that also. And if you live in a rust belt state, corrosion inside harnesses is a VERY common cause of circuits staying open when you don't expect it - so identifying WHERE IN THE DAMN COUNTRY you are is pretty important.

Wiring diagrams are linked in paragraph 4 or 5 of the megathread, help yourself.

But given this new info:

B2799 Engine Immobilizer System ==> This code is suspicious as hell. Do you have another key you can try? Have you tried unplugging the negative batt terminal for 10 minutes then trying with another key? (Your DC is obviously equipped with immob, thus chipped key, so ... the symptoms you describe right now could be related, although usually in the past folks with immob no-start would have the engine STARt but die within 1-2 secs!)

I'm going to toss some stuff out there as an add-on related to the rest of it.

First off, corrosion in the cables is highly likely in this case based on the charging symptom. This is my 75,000 mile, always-in-southern-USA truck, which has seen zero salty roads: https://www.tundras.com/threads/1st-gen-psa-clean-your-battery-terminals-you-lazy-sods.131635/

We have so many people go immediately to replace the starter, which is an unnecessarily difficult job, only to find the starter wasn't the problem, it's the damn cables. But that aside... you're clearly turning over, just not firing, so there's something else going on.

The crankshaft position sensor, whose wiring often gets mis-routed during timing belt install and can get clipped in the first few thousand miles, is required to engage the fuel pump, thus to keep running. You really need to check that sensor to confirm it's plugged in properly, and that it's not routed improperly, i.e. at risk of being clipped by the pulley/serp belt. Not to be confused with the camshaft position sensor, which in earlier years (not yours) had problems with getting clipped behind the driver's side valve cover, by the timing belt.

If not the crank position sensor, and unplugging/replugging it does nothing, and you find no damage to its wiring or wire loom ... there are two coolant temp sensors on our '06es, and others have reported no-start conditions if the one the ECU uses gets unplugged. Go back over all wiring you recall unplugging during the timing belt job, unplug each sensor, and re-plug.

It's worth looking at fuel, since it's turning over. Have you done anything to confirm if you're getting fuel to the fuel rail? Fuel pressure test at the fuel rail? Or if no pressure test possible for you, confirmed power at the proper leg of the fuel relay? Attempt to jumper the pump to always-on at the relay?

If I recall the fuel circuitry and operation properly, the fuel pump primarily engages in two cases:

1. You have the key turned all the way forward in "START" position (it's not active w/key in "ON" position).
2. The engine is receiving input from the crankshaft position sensor indicating the engine is running.

A lot of times, if your fuel pump is failing, you can resurrect it for a couple/few starts by having someone slap on the side of the tank while turning over the truck. It's worth a shot.

That's ultimately the initial info I'd send you off with. No-start after timing belt is suspicious, just because if you didn't get the timing right, you potentially wouldn't start (and can seriously FUBAR some stuff), and some of the connectors like the two coolant temp sensors and crankshaft position sensor are required to be plugged in properly to start. But the other info about having issues prior to this starting which could point to problems with corrosion in the wires ... it's another good observation. It leaves a broad canvas for us to throw shit at and see what sticks ... but, not in a good way

 

Thanks so much for the reply, very useful information.

I agree the engine immobilizer code is suspicious, I have 3 keys that seemed to all work, when I ran into this issue I tried all 3 of them and eventually one of them worked, but I think thats just fluke.

I will check and clean my battery terminal cables well, that could be an issue or at lease contributing factor.

The only reason I don't think its a crankshaft position sensor issue, is because when it does start it starts up and runs fine, and has no codes for the CPS, but its still worth a look, along with all other wiring/connectors including those coolant temp sensors you mentioned.

as for fuel, I could be being naive but I thought I could hear the fuel pump prime when the truck is in the "on" position, but I guess that dosent necessarily mean Im getting proper pressure. Another thought is that if it was a fuel issue I would at least get a couple burps/farts when cranking from a small amount of fuel getting into the cylinders, but rather Im getting either absolutley nothing or the truck starts fine, no in-between

As for the timing belt, Im pretty sure its all aligned correctly, and if it wasnt youre correct in saying it would/could FUBAR some stuff. I also think it would probably either not start, or run horribly.

Im thinking it has to be some sort of electrical gremlin either caused by something I did during the timing belt job, or caused by moisture/corrosion somewhere in the truck.

 

Yeah, I'm suspicious about that immob code. I'd love to see it cleared, see if it returns after removing neg- batt cable for 10 and causing everything to reset.

Speaking of resetting, did you do anything else? clean the throttle body, for example? touch anything related to the throttle body, its connectors etc.? Anything that would change the way the truck would run?

Just doing something haphazard like removing the pos+ batt cable instead of the neg- could result in blowing a fuse. It's a common mistake, always remove the ground first/only, not the positive cable when. Positive will often spark when reattached and that can surge/blow fuses.

To that point, have you checked all the fuses? Check all the fuses in the engine bay, including the square ones, etc. Blowing square fuse, or arc'd fuse can result in things like this, that's the dude's 140A square fuse in the engine bay, he was getting no-charge/intermittent charge because of that. Of course,

There's a lot to check, I know. Maybe use the chart inside the lid to think about what may be the culrprit.

But again, I'd be doing that after I unplugged and firmly replugged every electrical connector i disco'd during the TB/WP job. And I'd probably inspect inside each connector to look for bent pins, where applicable.

If it starts - but you're saying it won't start at all right now, right? - then it absolutely could be a damaged/faulty CPS. Taken from the megathread infodump, this is what typically happens to the crank position sensor harness.

Correct, or using ether/starter fluid sprayed into the intake or cylinders should result in ignition if you're getting spark. Which is obviously another thing to test. If you're not getting spark at all, that would be a hugely helpful symptom to find. You need fuel delivery, properly times hot-enough spark, and (metered) air in order for EFI engines to run. Confirm the three. If one is missing, suss out why.

As for the fuel pump, I definitely don't hear mine kick on when I put the key to ON. but maybe your DC is different, I dunno. My AC also doesn't have immob. And my truck uses RS3200 for unlock/lock/security, whereas I think your DC uses the BCM if I understood @BubbaW right.

Typically one of the two, yes. But ... we've had guys on here with ever-so-slightly-off timing who were only seeing misfire on one or two cylinders and it went away under load. In that case, they had a '05-'06 thus a VVTi engine like yours, and they'd done the cam seals "while in there", and didn't install the necessary service bolt to lock down timing while dicking around in the top end. If you didn't touch the cam seals, this likely wouldn't apply to you.

It's possible on the electrical. Sometimes just unplugging and re-plugging cables one-by-one (re-plug before moving to the next) and looking at the back side will show a problem. Like, taken from this thread, note the green copper oxide on this plug that was a dead giveaway water had gotten into the in-dash fusebox. but I still don't think that's your issue.

​

 

Thanks again for all of the information and suggestions, you have been more than helpful. I noticed my carpet was a little wet from what I’m assuming is a leaky windshield. After some further investigation it turns out that my fuse box and the connectors associated are covered in that green copper oxide crap. So that’s been pulled out of the truck, next step is to source a fuse box and the associated connectors, and replace allllllll of it.

this is going to be a difficult and time consuming job but at lease I’ve found the issue, or at least I hope this is the issue.

 

I would put money on the fuse box/junction box being toast, from water intrusion. I had similar symptoms as what you describe. My truck is also an Alberta vehicle, not that that should have anything to do with water intrusion, except possibly the fact that prairie vehicles often have stone-cracked windshields that are more prone to leaking.
Pull a few connectors out the lower half of fuse box/junction box and inspect for corrosion. If you see any, the internals are probably in bad shape, and replacement is the only real fix. Toyota OEM part only, and you’ll need your VIN to get the correct version. Sit down before you look at the price tag.

 

Just replace the junction box. The connectors are fine, or should be IMHO. That’s all I’ve ever seen anyone else do.

You need to figure out if the water is from a windshield leak or coming from the a-pillar. Water hose test may help. Replace whatever is causing the leak.

Do me a favor and post some pics of stuff so we can reference it later, it’ll help others. I didn’t think to ask about carpet being wet but that’s a great diagnostic step.

Happy to see you at least have a bit of direction now. I realize handing a half a dozen options isn’t ideal, but … there’s so many things it can potentially be, might as well show all the bases…

 

Alright, so ive found a fuse/junction box directly from Toyota, their about $800 CAD (good thing i was sitting down), so im going to try to find one locally in a part out vehicle to try to save some money, I found an 06 DC tundra, but it is not the limited trim, maybe it will be the same??. Youre totally correct in sayng that im going to have to find the leak, replacing the windshield i think is going to be a must since its cracked and i can hear wind leaking in the top seal, and then use tape to seal up the A pillar clips? I also dumped a whole glass of water in my sun roof tray to make sure the drains are working correctly, and they seem to be flowing just fine, but i blew some compressed air through the lines to be safe.

Here are some pictures of my fuse box, looking quite crusty.

 

So here's what I'd tell you about your integration relay/junction box there.

"At least one member here" (I use that phrase a lot, might need to trademark it, but I'll quote it for now), @RUSTYNUTS, was able to take his, crack it open, clean up all the contacts, and reinstall to get a working vehicle. But I think he mentioned things getting squirrely recently, he just wasn't sure if it was his starter potentially going haywire again or this box.

At least two other members, @daveeasa and @DJenerated (I think, it wasn't you, was it @Mr.bee?) had to replace their integration relay because of a wiring mishap and I think they both bought used parts.

I think, as long as the configuration of the plug-ins matches exactly on the replacement, it should work, if you want to replace. It's worth a shot at least and I'll be shocked if you're paying more than 150 CAD (I'd expect more like 100-120). If it has a part number on it, it should be in the format of #####-###c# where # is a number of some sort, and the trailing 5 characters are often "-0#0c0". It may be on the back cover? For best results, try to match the part number. If that's not possible, make sure the plug layout is in the same order/shapes, and the words above/below each plug match.

I'll also page @BubbaW, you have any thoughts here?

 

I know i still have mine, but its not where i thought it was, but i called the dealer to verify, to pass the buck. If it was wrong, it would be on them. & i could trade it in until i got the right one. But i got the right one.

 

I bought a new Oem part. It’s working flawlessly. I have my old one if it’s of any value, happy to send it. No idea which pieces are fried and which aren’t. Could be a simple fix.

I wonder if you took mine and stuffed your parts in if it might work flawlessly? I am pretty sure my traces are all clean given it was a so cal / central coast truck for it's life before I created trouble for myself.

I would suspect that I only fried one chip, it was really only low beams and high beams with stalk switch, high beams with pull forward worked fine.

 

The one you need should have the part # PP-T20+GF10 which will then match what you have as shown in the pic you posted above.

For whatever reason and on all the interior fuse boxes I've seen, Toyota chose not to use the normal 10 digit alpha/numeric characters.



just one of many found online....

Toyota PP-T20+GF10 Fuse Box T53496 - OCO Industrial (teamequip.com)

 

When I got my replacement box the VIN was critical to getting the correct one for my truck’s build configuration; I placed the order (through www.toyotapartsdirect.ca/) for the part number I THOUGHT was correct, but they called me to verify my VIN, and correct my order for the appropriate part.
If the vehicle you’re getting the used part from is not the identical trim/build package as yours, you’d likely have some functionality issues. If the used part is cheap, it’s probably be worth trying, but be prepared for something(s) to not work perfectly. Or, just get the 100% correct, new box.
For what its worth, my new junction/fuse box has everything working perfectly again.
Seal the A-pillar trim holes with butyl tape, replace your windshield and don’t look back.

 

Thanks for all the help guys! I apricate all the help and suggestions, I cross referenced the part number across all 05-06 model tundra and sequoias should all be the same fuse box??? there are a couple of local used ones in parts cars near me that i think i am going to try before i buy an new one from toyotapartsdirect.ca in order to save some money, maybe i should just buy the brand new box but i think these ones are at least worth a shot? maybe?

I dont think im going to attempt to fix my current box, that sounds like a headache and probably wont work out very well for me anyhow.

Still not sure if replacing my corroded connectors is necessary so the corrosion dosent come back or cause any connectivity issues between the harness and the fuse box, or if a good clean of them should suffice.

Im looking forward to this step! i havent even owned the truck for a week yet lol, so i am just stoked to drive it!!

 

I highly doubt the connectors are corroded. I think you’ll be fine swapping out the integration relay alone. But that’s just my opinion, based on the fact that nobody else with similar corrosion needed to do anything (they bothered to mention) with the connectors.

 

Sorry, what exactly do you mean by integration relay? is that another term for fuse box/ junction box?

and yeah maybe youre right, a good clean of the connectors could be all it takes, but they are pretty crusty as you can probably infer from the sections they plug into on the fuse/junction box

 

yes.

 

It’s more than just fuses. It’s got smarts.

 

I was able to save mine by disassembling and thoroughly cleaning it, but it was nowhere nearly as bad as yours. I had only 1 area with corrosion, and no broken traces within the box. I did also have some of your same symptoms; wet carpet being the dead-givaway. Also, headlights not turning off or turning on by themselves, and the alarm suddenly being triggered hours after I parked it. Then the drivers power door lock stopped working. With nice weather-no symptoms. Only acted up when we got heavy rain.
A compatible swap and fixing the leak.... sounds like you're on the right track.

 

Awesome I’m glad to hear you had some similar symptoms, it’s nice to hear that I think I’m on the right track.

Totally, I’m hoping the box from the sequoia or tundra I get is the same, I think they are after crossing part numbers but I won’t be able to tell forsure until I get my hands on them.

I will keep this forum updated with my findings!

 

https://www.youtube.com/watch?v=W6yBL7wxr2I​

 

RE: corroded connectors, it stands to reason that if the pins coming out of the box have corrosion on them, then the connectors that mate with those pins will have corrosion in them. Mine did.
I tried a variety of methods to clean the green crusty corrosion out of the connectors, and had good success using a spray can of electrical connector corrosion remover (off the shelf at Canadian Tire) and dental ‘toothpicks’, those fine little brushes designed to fit into small tooth crevices. Got them from the pharmacy.
After cleaning all the slots of a connector, I used compressed air to blow out the majority of the liquid residue, then sprayed them copiously with MAF cleaner (auto parts store, CT, etc) to remove any residual moisture and crud created by the corrosion removal step. You want those suckers to be as dry as possible, to stall/prevent future corrosion. Then I packed the slots of the connectors with dielectric grease. Wipe off any excess from the external surfaces of the connector.

 

So.... have you been able to find a replacement integration relay yet?

 

Ok thanks guys! I’ll clean up the connectors tonight and replace any pins that are in really bad shape.

I was able to find a new fuse box out of a 2006 sequoia limited. From what I can sell so far they are the same. Hopefully I don’t have any issues installing this one!

Thanks guys, I’ll keep you updated

 

Alright guys! So last night a friend and I were able to put the sequoia fuse box into the tundra, I was a bit skeptical if it would work at first but after examining the boxes closely I believe they’re the exact same, they even had the same fuses and relays across the board. When I was looking at the harness on my tundra comparing it to the bit 0f the one I took off the sequoia, I noticed they use different pins in the fuse box, neither harness (tundra/sequoia) use 100% of the pins coming out of the fuse box, I guess was Toyotas way of making a more standardized part.

I was able to clean up the connectors with one of those dental toothpick pipe cleaner things and some contact cleaner, then finished off with a bit of dielectric grease. so, thanks Xcruiserguy, that method worked amazingly!

So far, the truck starts flawlessly and the other issues I was having seemed to all be gone! (headlights and HVAC staying on, alarm sounding at 2am... etc.)

next step is to get a new windshield installed and seal up those holes in the a pillars.

Thanks again to everybody who chimed in on this thread, it made this repair ALOT easier.

now we can move onto doing some fun stuff and enjoy the truck. Up next is a good Bluetooth deck, lift kit and some 33's!

 

Hey, if you need any input any of that fun stuff, hit the 'megathread' sticky that's the 1st link in my reply for this thread. It has all the info you need if this is your 1st rodeo with 1st gens, for suspension and audio stuff and more.

Glad that's what it was, and hope they don't find anything ugly when they replace the windshield (corrosion where it seats). I really need to take a deeper look into the A-pillars, try to understand how water is able to get in. I know Professional Hand Model's build thread had some info about the A-pillar windshield trim, but I suspect there's other avenues. And the common trend I'm seeing is, it looks like the water is actually traveling down the wireloom for the harnesses, entering that way.

 

ok thanks ill check out that megathread forsure,

looking like ill replace/reseal the cowl clip/screw things as well.

im also really hoping that the windshield seat isnt toooo crusty... hoping it can be resealed without any major bodywork.