Printer Friendly Forum Posts - 2000 sentra r/s no tach signal

This is for a 2000 Nissan Sentra 2.0. I just installed the DEI 556U to bypass the immobilizer and can get the car to start up with the remote but it shuts down after about 20 seconds. Then it tries to start up again, runs for 20 seconds and shut down again and so on..

I read that the tach wire needs to be hooked up. I found misleading information from a number of sources so I'm a bit confused.

According to the factory service manual I can get the RPM from the instrument cluster at pin 45 which is a solid green wire. I tried that wire but the unit still doesn't recognize the signal. I even tried to find a wire with 2-7 volts [ac] with a multi meter but none of the voltages increased with the engine speed.

How else can I make the tach signal be recognized?

Tachometer

RED

(-)

AT IGNITION COIL

Thanks for the response. I was kinda hoping I wouldn't have to run the wire all the way from under the engine bay.

According to the manual it says:
Violet/White Wire: Tach input/constant power input wire. This input provides the module with info about the engines rpm.
Note: This wire has the same function with the constant power snensing input so is is an alternative solution when tach input does not supply proper signal. If connected to the constant power sensing input, it is an easy way to sense if the remote start has been successful [tachless method].

If Im reading that correctly, thats the same as voltage sense? So basically I could just connect the violet/white wire to an ignition wire? Or if not, how should I wire it?

monday morning bump!!

Would like to finish the install today but need to figure out this tach signal problem or how to make it read voltage instead

i suggest tach, but it you must use voltage sensing, it seems to always work best if its connected right to the battery under the hood with a fused lead. so, i say if you gotta go under the hood anyway might as well go for the tach wire.

ckeeler wrote:

i suggest tach, but it you must use voltage sensing, it seems to always work best if its connected right to the battery under the hood with a fused lead. so, i say if you gotta go under the hood anyway might as well go for the tach wire.

So constant power input is the same thing as voltage sense? the unit is just looking for a 12-14V input when the car is started? Wouldn't I just be able to tap the wire into the ignition wire on the steering column?

The reason I'm trying to avoid under the hood is because it's pretty cold outside here in the North East and I don't have access to a garage to mess around under the hood.

What unit are you trying to install? the ones ive done monitor the voltage with the vehicle at rest and then check it again after remote starting to see if there is an increase in the voltage. thats how it knows its running. its that higher voltage it needs to see. thats also why ive had better luck going right off the battery.

ckeeler wrote:

What unit are you trying to install? the ones ive done monitor the voltage with the vehicle at rest and then check it again after remote starting to see if there is an increase in the voltage. thats how it knows its running. its that higher voltage it needs to see. thats also why ive had better luck going right off the battery.

It's just an Ebay special remote starter unit with alarm.

I will try hooking it up to read voltage and see what happens. Thanks for the help.

OK so I connected the signal wire to the ignition wire on the steering column and tested the signal thru the alarm. I got the beeps from the horn which according to the manual meant that it accepted the signal.

I remote started and it shut off again after 5 seconds. I said to myself..wth!!

THEN I realized something-I forgot to connect the wire for the hood pin switch. According to the manual the unit will shut down if it suspects the hood is open. I think once I connect the hood sensor I should be up and running.

What do you think?

the hood pin needs to be connected for sure.......but it wont fix this problem because if it was disconnected the unit cannot see the hood as being open anyway. i think this is a problem with your 556U

ckeeler wrote:

but it wont fix this problem because if it was disconnected the unit cannot see the hood as being open anyway. i think this is a problem with your 556U

UGH..I'm back at square one then.

Is there anyway I could verify if the 556 is busted? [by testing it somehow?]. I assumed the way the system works is it only uses the signal to start the car but once the car is started, the ignition no longer needs the signal from the key to stay running.

In the manual is says this under the description for the hood pin wire:

The switch must supply a ground output when switch is opened. This input will disable or shut down remote start when the hood is opened.

So when the system is "closed" is it supposed to be looking for a positive signal?

Also, I read that if the car notices a check engine light that it will shut itself off during the remote start procedure? My check engine light just came on the other day due to the remote start.

disconnect the power to your bypass. try and remote start with the key in the lock cylinder. dont turn it, just put it all the way in. then remote start. does it stay running? if so you have a transponder bypass problem

Thanks, I will try that in the morning and see what happens.

Ok I tested the bypass by cutting the power to it and remote starting with the key in the ignition but in the off position. The car starts right up but again, it just shuts off after 5 seconds and the check engine light came on after the second attempt.

do the same thing again, but this time turn the key to the run position just after you push the remote start button. maybe you have missed an ignition wire that needs to be powered or have it connected to accessory instead of ignition.

ckeeler wrote:

do the same thing again, but this time turn the key to the run position just after you push the remote start button. maybe you have missed an ignition wire that needs to be powered or have it connected to accessory instead of ignition.

The car started up and stayed on when I turned the key to the run position. The only thing is that after about 15 seconds of running I could hear a noise from under the engine bay, it was probably the starter grinding so I shut it down.

I read in another thread it was OK to make a Y connection to the two ignition wires-which is what I did. Would that be the problem?

its not ok to do that. you need to power that other ignition wire with a separate circuit. also your car has 2 starter wires that have to be powered. did you power both of them? it wont start if you dont. you will need a relay to power it. dont make a Y and connect the 2 starter wires together.

ckeeler wrote:

its not ok to do that. you need to power that other ignition wire with a separate circuit. also your car has 2 starter wires that have to be powered. did you power both of them? it wont start if you dont. you will need a relay to power it. dont make a Y and connect the 2 starter wires together.

I made a mistake in my previous post. The first ignition wire goes to the pink wire on the alarm and the second ignition wire goes to the pink and white wire on the alarm so the ignition wires are seperated.

As for the starter wires, yes the car does have two but the alarm only has one wire [purple-started output (+) connect to vehicle's starter wire]. Is there a diagram on the forums on how to wire the relay to power the second starter wire?

Yes. ill also post a diagram. there are 2 ways you can do it. if your unit has a second starter negative output (it will be a small wire that supplies a low current negative trigger the same way the purple start wire supplies 12v). if you dont have one on your unit you can trigger a relay off the purple start wire.

ckeeler wrote:

Yes. ill also post a diagram. there are 2 ways you can do it. if your unit has a second starter negative output (it will be a small wire that supplies a low current negative trigger the same way the purple start wire supplies 12v). if you dont have one on your unit you can trigger a relay off the purple start wire.

off topic but I just wanted to say a big thank you for continuing to assist me. Other people might have been tired of me by now with all these questions LOL but I really appreciate your help-I'm learning a lot.

As far as I Can tell it has only one starter wire, which is positive output.

no problem. everyone on here is helpful and have lots of good ideas.

Are you sure you have a key with a chip in it? I have two 2003 sentra's, my uncle has a 2000, and ive looked at a bunch before buying my two just within the last few months, and have yet to run into one that has a chip in the key!

CC installers tried getting me for the bypass, but i was sure to use a plain metal spare key when dropping the cars off to CC installers.

The dealer can tell you for sure if you have a chipped key

carhigh wrote:

Are you sure you have a key with a chip in it? I have two 2003 sentra's, my uncle has a 2000, and ive looked at a bunch before buying my two just within the last few months, and have yet to run into one that has a chip in the key!

CC installers tried getting me for the bypass, but i was sure to use a plain metal spare key when dropping the cars off to CC installers.

The dealer can tell you for sure if you have a chipped key

I'm 110% certain I have a chip in my key. Not all 2000-2006 Sentras were equipped with the Immobilizer system. The base models with the 1.8 engine didn't have it and neither did the base 2.0 models IIRC. My 2.0 model is the "sporty" version for the 2000-2001 line up and it did come with immobilizer as part of the sports package.

For the 2002-2003 Spec V models with the 2.5 L engine, I believe immobilizer came with the Rockford Fosgate premium package.

If I try to start my car with a regular hardware made key, I can sit there and crank all day but the motor won't turn over. I have to insert the chipped key before it will start.

Found this diagram online-just wanted to make sure its the correct way to wire up the relay for the 2nd starter wire.

posted_image

For pin 86 on the relay does it matter where it's grounded off?

ckeeler wrote:

no

LOL no as in that's not the correct way to wire it or no as in it doesn't matter where it's grounded off?

just give it a good clean chassis ground. it doesnt matter where.

thats okay to wire like that but i prefer this

85 - constant 12v fused @ 5 amps
86 - negative 2nd starter output from alarm or rs 200ma - 500ma)
87 - constant 12v
30 - to second start wire on car.

this only works if the unit has a negative out for start during remote start sequence only.

true. i also dont like that diagram that much. didnt you use one of the ones i posted for you earlier on this thread? the problem with using a GWR from the unit is makes the relay energize the second start wire the whole time. you only need to energize it for START.

ckeeler wrote:

true. i also dont like that diagram that much. didnt you use one of the ones i posted for you earlier on this thread? the problem with using a GWR from the unit is makes the relay energize the second start wire the whole time. you only need to energize it for START.

ON SNAP! I didn't even see the diagrams you posted in the previous page. Maybe the pics didn't show up when I viewed that page or something. I will use your diagrams.

Thanks again.