- 06-25-13 09:09 PM #1Cadillac Owners Enthusiast
- Automobile(s): 99 STS, White Diamond
- Join Date
- Nov 2008
- Cape Girardeau, Missouri
URPAS (rear parking assist system) Added
With some horse trading and assistance from forum member N*Caddy I have a fully functioning, factory URPAS system in my '99 STS. Not the easiest thing but definitely doable.
If you want to do the same, here are some tips:
1) You will need these things from almost any 2000-2004 or so GM vehicle with the system: The four sensors and full harness. The URPAS module and wiring harness clips. The telltale indicator that mounts in the center of the back window. A 2000+ RIM (rear integration module). Electrical connectors to the RIM--the part numbers for the bodies are 12084945 and 12110088. At least seven Micro 100 small-gauge female sockets part number 12146447 unless you've clipped off these connectors and plan to splice. Electrical schematics for both your car and from one where the URPAS system was available.
Also some length of wiring harness cut from a junk car if you want to keep colors the same
2) There is plenty of room to mount the sensors in the factor locations as nothing is in the way.
3) For the URPAS module inputs, you can make pigtail splices (carefully strip insulation only from a short section of wire, wrap with new wire, solder and tape) for power, ground and vehicle speed sensor from the harnesses leading to the RIM and CVRSS (variable suspension) modules. I'm almost certain that the wiring for the CVRSS will be there even if you have an SLS without the variable suspension. The last input you need to the URPAS module (the backup light circuit) is available on the other side (driver side) of the trunk in the harness leading into the trunk lid.
4) Other than the telltale, the only output from the URPAS module is for audio and it runs to the RIM location.
5) With the complete rear seat, rear headrests, sail panels and rear assist handles (in the headliner) removed you can drop the headliner enough to cut the hole in the headliner for the telltale. If you have a factory sunroof (like I do) be aware there there is a magnet glued to the headliner substrate in the exact position where the telltale should be mounted. Trust me here if you have the factory sunroof. Forget about the original magnet and get a small, powerful rare earth magnet that you glue to the telltale body in a position where it will contact the narrow metal bar you see above! I'm not sure what you will encounter if you don't have the sunroof but something tells me it will be easier
6) You cannot simply replace your existing RIM module that has the audio input for the URPAS system with a 2000+. Why? You will loose your gas gauge! You must install a second RIM module! This is why you need the RIM connector bodies and the female sockets! For the second RIM module this worked for me: From the original RIM harness I tapped into both (battery and ignition) powers, both grounds and ran the new URPAS audio input to connector #1. Connector #2 has only the infamous purple (main data) wire. Cut either wire leading to B3 or B4 pins of the original RIM and loop to pins B3 and B4 of the new RIM. This is a "one-wire" communication system so it does not matter where you tap in as long as you maintain a continuous loop.
7) If the sensors are not your body color, carefully sand off most of the paint before repainting. If the paint is too thick they will not work properly.
- 06-25-13 10:24 PM #2
My car has a factory sunroof and URPAS. They didn't bother putting a magnet in the telltale. I wouldn't worry about support there, that area of the headliner is strong.
- 06-26-13 12:03 PM #3
Re: URPAS (rear parking assist system) Added
My headliner definitely droops without the magnet at the center rear.