supra9398

I am having a weird starting issue with my 2000 SC 400. I have searched this forum (and some others), but I cannot find anyone with these exact symptoms. Here it is:

- The car will not start. No clicking, no sound at all - I turn the key and nothing happens.

- The dashboard lights illuminate as normal, as does the climate control display. Nothing else does.

- The battery is perfectly fine, I had it replaced in July and I just checked the voltage earlier today.

- When I tried to jump start the car from another vehicle, nothing happened.

- When I tried to jump start the car from a portable jump box, the alarm went off.

- The battery in the key is fine, I just put in a new one to make sure.

- When the key is in the "ON" position, the transmission will not shift out of park unless I hit the shift lock override button.

- The remote locking function only partly works. The "lock" button works normally (gives one beep) if the vehicle is already locked, but does nothing if the vehicle is unlocked. The "unlock" button works normally (gives two beeps) if the vehicle is already unlocked, but does nothing if the vehicle is locked. The interior lock buttons do nothing.

- No, the car is not out of gas.

- There are no modifications to the vehicle; it is 100% factory stock.

Given the above symptoms, I believe the immobilizer system is malfunctioning. Based on your knowledge and experience, do you guys think this is the case, or have I misdiagnosed it? If it is the immobilizer, is there anything I can do to fix it myself?

Thank you in advance for any help.

Zerodrag

iTrader: (5)

I had a similar problem, but on my Maxima. It turned out the starter was bad. It cranked slower and slower during the previous months until it stopped cranking altogether. Not sure if it's related, but something to consider.

oldManTan

i have the same problem, i had to run a switch from the starter relay to the inside of the car. i still haven't figured out how to fix it. hopefully this thread we'll figure it out.

tfwnoturbo

Try to jump the starter, someone here had something that sounded somewhat similar to you and that is what seemed to work.. Another thing you may wanna try is to check the resistance in the battery leads since our cars tend to have problems with that. Good luck.

Luxor

iTrader: (15)

This is not an immobilizer problem, the immobilizer will still allow the starter to function but will cut fuel from the engine preventing the engine to start and run. I am guessing that the ignition switch may be bad.

pogoism9

iTrader: (1)

This. That being said, there is still an Anti-theft system that is separate of the Immobilizer. If it works anything like the MKIII Supra, it can cause the symptoms that you are getting, but its highly unlikely, from my experience, the Old school anti theft is pretty trouble free.\

Another thing to check is your neutral start switch. It acts just like a clutch switch on a manual, if the clutch pedal isn't engaged, you will get no crank.

supra9398

Thanks for the input, everyone. How would I check the ignition switch or the neutral start switch?

pogoism9

iTrader: (1)

Try looking for a switch on the brake pedal for starters. If there is one, pull the connector and bridge the 2 pins in the connector and try to start the car (make sure you are in park). If the switch is bad the car will start if you bridge those pins in the connector.

oldManTan

you don't need to hold the brake to start the car in park

pogoism9

iTrader: (1)

I was in a manual state of mind when I wrote that

supra9398

If it was the ignition switch, why would that affect the alarm? This is why I think it has something to do with the immobilizer.

Ramblerman

I have the occasional problem with my 96 SC 400 that is some what the same as you describe, but it is caused by a bad set of contacts on my starter, which is located under the plenum & I will fix that when I tear the engine down to do the T belt & water pump. Check all your grounds also. 10$ part 300$ labor charge if I pay some one else to do it. Yoda got us on that one!

supra9398

Would that affect the alarm as well?

supra9398

Update: OBD-II diagnostics is not working, will not link to the engine. The equipment is not at fault, because I tested it on my other SC 400 and it worked just fine. Apparently the ECU is locking everything out.

pogoism9

iTrader: (1)

The immobilizer only cuts fuel. It wouldn't lock you out of OBDII. The only other way the ECU could cause this is if it were bad.

Just for the hell of it, check your AM1 fuse in the engine bay. I have attached a PDF that is the power source layout for a 99. Should be the same. Walk through that starting at AM1 and make sure your electrical is in order.