like the title says is there any way to by-pass immobilizer for the 99 maximas? will chaninging the engine harness and ecm to a 96 harness and ecm do the trick??

 

You need a 556u made by DEI and also a spare key to go in the module. I use it for my remote start installs to by pass this in Maximas. Why are you trying to bypass this?

 

my car is acting unprogramable. two nissan dealerships have now told me that my car wont hold programing. everytime i try to start my car the security light stays on and just cranks. there is something wrong with my theft and immobilizer system. The car thinks it is being stolen even right after programing. So i want to completly by-pass the theft and immobilzer system. what is a 556u and a DEI??

 

DEI=Directed Electronics Inc, a company that makes security stuff.
556u is the part you need.

This part can be ordered from any car stereo shop/chain....

 

Works great for a remote start, yes. Won't help his problem at all, though. His ECU won't hold the programming for the key..

OP: Changing out the ECU and harness should be all you need to do, probably have to swap out some emissions equipment though (to make the new ECU happy).

 

I'd use a 98 ECU. Same emission equipment with the exception of the 99's electric EGR valve (which doesn't apply anyway due to the 3.5 swap).

 

i have delteded all the EGR. can i use an earlier year ecu and harness to fix the problem and not use the immobilizer and theft system? not only will the ecu hold programming it is still being put in lock mode. the security light stays on. nissan still wants 4200 to fix the problem. they want to change the MAF the engine harness and ecm. Can I just get a 96 engine harness and ecm and completely eliminate the immobilizer and theft system?

 

reason i ask is because i spoke with a tech at jim wolf and asked if they could make an ecu that by-passes the immobilizer and theft system because I had found out by searching on the org here that they have done it for a few people. Only They told me they do not do it anymroe and he told me to get a engine harness and ecm from an earlier year and it would ultimately eliminate my problem. Just looking for some reasurence from the maxima gurus.

 

I am going to bring this back from the dead. As some of you may know, The Russian's car is not running right now. I swapped a DE-K into his car and we tried running the 98 ECU and 98 engine harness but the immobilizer is preventing the car from starting. Would the 556u work since we already have the harness and ecu? Immobilizer is something I don't know much about, I have done 2 VQ35 swaps and a VQ30 so I know my stuff and I know its hooked up right, the immobilizer is just being a pain. I am going to make the trip down to Oregon soon to make his car work soon and I want to make sure the trip won't be for nothing. Any help would be great. Here is the link to his thread also: DE-K Swap Thread
Thanks,
Zack

 

The immobilizer function is built into the '99 ECU so there's something else keeping the car from starting. Getting fuel and spark?

 

No fuel. I checked the relay because it would buzz and the pump wouldn't turn on. I tapped a wire onto the relay ground wire and grounded it and the fuel pump came on. I unfortunately didn't get a chance to check spark before he left. Apparently nissan claimed the ecu didnt even get power.

 

I probably can't help, but since I have a NAT-cursed '99, I've had some experiences with the immobliizer. ( all bad ) ... Most of this is repeating the obvious, but...

The NAT system uses a reading coil around the ignition lock, a small NAT module next to the steering column, and the '99 ecu talks to the NAT module on start-up, to verify the key code. If your key has a flaky chip, if the reading coil is intermittent, if the NAT module is bad, or if the ECU can't read and verify the key chip, the car won't start. Also, if you reset the ECU with the little screwdriver adjustment in the side of the ECU, you can trip out the NAT function and you can't start.. Happened to me twice at the track. Use an OBD2 code reader instead.

Using another year's ECU should make things work - will need another harness, since the '99 ECU has a different pinout. Also need to consider if you have an early '99 or a mid-year '99... A non '99 ECU will ignore all the other NAT functions, so if you can't get the car to start with a '98 ECU, you have other problems besides the NAT. Any add-on module intended to defeat the NAT would have to duplicate the serial data transmission that goes on between the ECU and NAT module. That would be interesting to see....

 

He does have an alarm with remote start that was installed by a shop. Since the immobilizer is going to need to be bypassed, the remote start will need to be bypassed as well, right? Could the remote start module be the reason there is no signal?
Thanks,
Zack

 

There is no immobilizer to be bypassed. That entire function was removed along with the 1999 ECU.

 

Bumping an old thread...haha but i see getting the 556u is an easy way to go. Just want to verify this is the correct item??

How hard is this to install?