Engine Swap- help needed

My 330K mile Sequoia Limited engine gave up, so I bought and installed a replacement engine with lesser miles. The mechanical install went relatively easy, however I’ve run into a snare electrically. When attempting to start with the new install turning the ignition key, I got the instrument panel lights turning on, but nothing else (no starter or engine turning over). One interesting thing, the brake pedal is depressed as if it’s in a security lock out mode? Could that possibly be?

Would there be any engine computer code changes needed with the replacement engine before it would turn over?

thank you for any help!

also- there is a grey/green stripe light gauge wire coming out of the driver side firewall, that is not connected, and I’m not sure where it goes. Any suggestions would be greatly appreciated.

 

Where did you get the replacement motor? What year and model?

 

In addition to that ^^ which is pretty f'n important info...

Have you scanned for codes?

Immobilizer was a thing in Sequoia and some of the DC model Tundras.

 

I'll try scanning the codes and let you know. I'll also look at the immobilizer signals in the wiring. Thank you

 

I got the same year Motor '03 Sequoia Limited from Machichi's in Vorhee's NJ. They came as a recommended place and showed me the video of the engine running before they pulled it for me. Any other thoughts are appreciated.

 

I scanned to codes and got a

P0504 Brake Switch A/B Correlation and
B2799 Immobilizer Malfunction

any additional thoughts?

thank yoi

 

B2799 Immobilizer Malfunction

That's a problem, I'm guessing. Immobilizer is part of the security system which stops the engine from running in certain conditions.

"This DTC is output when one of the following occurs:
1) the ECM detects errors in its own communications with the transponder key ECU;
2) the ECM detects errors in the communication lines; or
3) the ECU communication ID between the transponder key ECU and ECM is different and an engine start is attempted."
​

Did your mechanic, in all their infinite wisdom, swap over the ECU from the other vehicle per chance? Are you using a different key, perhaps, or a valet key, or a recut key?

 

x2 on what Shifty said. Make sure that whatever replacement engine you installed, your existing 2003 Sequoia engine harness, ECU, and immo box (if it is a box on the toyotas) must be reused and installed on the replacement engine! At least for other vehicles, the immobilizer unit pairs up with the ECU and a chipped key. Normally the immo antenna is not paired. So four different components make up the entire immobilizer system, and three of those components must be paired together...and it's not something that a normal mom and pop locksmith is equipped to do.

If all of that checks out, then look for a bad ground wire somewhere.

 

Also, make sure you don't/never did have an alarm under the dash.

The symptoms sounded immobilizer-y, hence my 1st reply.

 

Side note, i very recently shipped two different 2009-13 KTM 990 ECU’s over to Slovenia in order to get the immobilizer completely remove from the ECUs. I just received them back last week. Spent a total of just over $900 for the work performed and the shipping both ways on both of the ecu’s. Slovenia is a loooooong ways away from oregon, but it’s the only guy in the world that does this particular work. My buddy’s and my 990’s are now immo free. I also took the opportunity to prune out absolute handfuls of now obsolete wires from the main wire harness. It feels good to have less computery shtuff to go wrong on our bikes.

Point being, immobilizers and lost transponder keys can be a huge nightmare when something goes wrong with them.

 

Thanks of the Immobilizer notes...We're using the original '03 harnesses with the engine and original keys. The blinking security key is on when battery is applied, and when the original key is inserted the security light goes out (I think a good thing). I do hear a slight thunk in the engine compartment when I turn the key, but that's all??

I'm looking at the wiring harness and fuse box and am wondering if the starter is bad...although the video I got from the engine shop of the newer engine showed it running and doing well.

Might also look into the Park/Neutral transmission position switch to see if there is something there? Brake pedal seems to be in s depressed position.

Thanks all for help with this puzzle.

 

In my sequoia at least if I use a non programmed key it still cranks, just won't start.

 

One other thing, with the key turned on panel lights lit, I can’t shift out of park. Thoughts anyone?

 

Are you stepping on the brake when shifting? My Tundra has an interlock pin that can get stuck with corrosion. A dab of grease and some pressing on it with a screwdriver may help

 

Park neutral switch is another thought.

 

Yes to pushing on the brake. I’ll try and figure where the park/neutral switch is located…thx!

 

Hi All - SUCCESS ! Almost. The engine runs and is smooth!. I ended up seeing in an old thread to pull the Starter (ST Relay) in the engine compartment and look for 12 Volts on pin 5 and if its there jumper pin 3 and 5 together. 1st time I didn't know the pinouts where 1 through 5 were, so I probed around and found 12 volts on one of the two big spade plugs (pin 5). I jumped it to one of the other smaller spades and lost the 12V...uh oh.... shorted it out and blew the 30 Amp started fuse which was upstream toward the battery. After replacing the fuse, I dug into the wiring diagrams and then found the ST relay pinout and measured 12V on pin 5 again and then jumpered it to pin 3 (other big spade socket) and the engine fired right up!!.

Next step is to understand why what's not working from the ignition switch wiring (all the panel lights work when I turn the key to start position) and the security key light goes out when the keys inserted. I'm thinking either a ground or the transmission Park/Neutral switch may not be working...will have to check the connectors.

Any thoughts would be appreciated!

 

No codes stored?

I want to say the ECU is responsible for grounding to complete the start circuit. i.e. if all pre-checks are satisfied, the ECU will trigger ground, and the truck can start. I recall in the past - probably the thread you're talking about, with the guy who was driving to Mexico or something and didn't have time to backtrace why this is the case, but - the guy was able to tie one of the relay pins to ground in order to start the check.

Sequoia had immobilizer, but I don't recall what year it started in.

 

Looking for help. For an 03 Sequoia, can anyone ID what this Black Green wire connects to (see picture). It comes through the driver side firewall (and is only with one other - which looks like the hood open indicator?)
The wire is only long enough to go to the engine compartment fuse box area. I wish I could look under the hood of another sequoia.

 

I traced this wire into the cabin (goes under the steering column and is bundled and looped with a bunch of wires, and my guess is connected to what maybe a computer behind the dash center console.

also I found this on/off switch under the dash, (never used it ) any ideas what it’s for? It was alway hanging there and didn’t appear to do anything when switched…thx!!

 

Definitely looks aftermarket the way the grommet is slit., maybe alarm system or kill switch or accessory lights. I’d probably trace out all the wires and remove.