2007 compass remote start

my info seem to show that its your typical chrysler mux install

Seconding robertsc's comment here - that shop is f&*%ing incompetent if they can't do a late model Chrysler. You'd think they might want to keep the dealer's business and learn how, no?

By one wire they mean the following:

For a while now (since early to mid '90s) car makers have controlled multiple functions of their cars on single wires...it's called multiplexing.  Many manufacturers do this with door lock/unlock. Chrysler is obsessed with it and controls lock/unlock, sliding doors, light switch functions, and many ignition switch functions that way.

On your Jeep Compass that one wire from the ignition switch controls the key-in-switch sensing, the accessory turn-on, and the cranking.  However, this is (reiterating again) nothing new.  As mentioned, the PKU-CH2X from Bypasskit has an output that is just connected directly to that wire...it can also be easily controlled with relays and resistors. Get your money back from the dealer, tell them their recommendation sucked, and any other shop should be happy to help you.

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C Renner's Auto Electronix
My service is cheap, quick, and good - pick any two

I have done plenty of Dodge/Chrysler with the single wire set up and nothing new, just a tad more work in some instances on prepping the unit for install but time of installing isn't that long at all. The resistor single wire based system has been in use since late 90's early 2000's.

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The wire I'm test'n isn't doin' what it's supposed to be doin'... I am so glad I printed that tech sheet, with the wrong info.
Do it right the first time... or I might have to fix it for ya

I agree with all the others here.

The Compass is not a "traditional" car electrically, in that the ignition switch only has four small wires going to it:

1. Constant (battery) power
2. Constant ground
3. Ignition (power when the key is on)
4. Multiplex wire. Inside the ignition switch are a few resistors, which are connected to the ground wire.

When the key is inserted in the ignition and turned, the switch connects the multiplex wire to the different resistors, based on the position of the key.

Basically, if you put a tester on the multiplex wire, it will show different signals to indicate the various key positions:

- key in ignition (but in off position)
- accessory (to play the radio)
- run (the position it stays in with the engine running)
- crank (the position you hold to start the engine)

Like the others said, this system has already been out for a year or two. Pretty much ALL the non-expensive Chryslers have the exact same system.

For example, Sebring, Nitro, PT Cruiser, Patriot, Compass..........if an installer can do one, he can do the others.

In addition to this, your car has Chrysler's Sentry Key anti-theft system, again, nothing new at all.

Inside the head of your key is a small transponder. If the car's doesn't "see" the transponder, it doesn't allow the engine to start, making it harder to steal.

In short:

-- The installer needs to be familiar with Chrysler's MUX (multiplex) system, which is nothing new, and

--The installer needs to also install a transponder, similar to the one inside your key, which turns on only when the remote starter is turned on.

The installer may use an aftermarket transponder module made specifically for Chryslers, or simply program another Chrysler key. I use keys because they cost me less, but either way works.

Again, the transponder is nothing new either. Chrysler's been using it since the '99 300M, as well as almost every other carmaker.

Again, I agree with the others.

The shop you went to was really nice to give away all their Chrysler business to the rest of us.


Advice:

--If you can find a shop that specializes in new-car dealership work, they're more likely to be familiar with your car.

--Nothing wrong with calling the big-box stores like Circuit City or Best Buy, but talk directly to the installation department, not the salespeople.

They should be familiar with your car, and able to give you a complete price quote with all extra needed parts. If they can't, that's a sign they haven't worked on your car before.

--Wherever you go, keep in mind that because of your Sentry Key, you're going to pay more than the advertised price in the window.

Also, I wouldn't charge you any extra to interface with the MUX system, because it's so easy, but some shops might.

--Also, when getting a price, ask if you're going to have to give up one of your existing keys. Since you only have two that came with the car, you'll probably want to pay extra to be able to keep what you have.

(They could charge you less, but they'll bury one of your existing keys in a universal bypass module.)

--No matter what method they use to deal with the Sentry Key, BOTH of your existing keys are required for programming.

Even if you're paying the extra charge to keep both keys, you need to bring both of them with you for the installation.