The UPRA isn't on Class II so it can't be scanned for codes. But the good news is there's a 2-pin diagnostic connector hanging off the harness near the UPRA module, and all you have to do is short the 2-pins and read the codes as follows:
- Ignition off
- Short diagnostic connector in PARK
- Ignition ON
- Apply BRAKE
- Shift into REVERSE within 5 SECONDS
The UPRA lights will flash codes. Post back what the lights do.
No lights? Check the fuse, and if still no lights either the UPRA module or wiring is bad. I assume no chimes either (if chimes and no lights, check the connector on the UPRA display).
The UPRA module is in the trunk, on the RH side near the wheel housing. You need to remove the trim carpeting to get at it. Item #3 in the attached diagram.
You'll see it right away when you pull away the trim carpeting... it's the small module (fits in the palm of your hand) with a single bolt through the top of it, connector on the side facing the rear of the vehicle. You'll also see the diagnostic connector hanging nearby.
I doubt it's the fuse... the UPRA gets its power from the 10A IGN 1 fuse, so if it blew a lot of other stuff would be screwed up too. It also gets its power from the 10A PRK/REV fuse, so my next question is are the reverse lights working? No reverse lights, no UPRA.
UPRA also need the RIM working right. Any RIM codes?
As for the cost on a UPRA module... we ain't there yet... let's do some testing first, starting with if the reverse lights are working or not, then shorting the diagnostic connector and getting the codes (UPRA light flash sequence). But if the module really is the problem, it's GM #25750800 and it goes for around $150 or so list.
Only on this GREAT forum can you get info like this.
The UPRA module is in the trunk, on the RH side near the wheel housing. You need to remove the trim carpeting to get at it. Item #3 in the attached diagram.
You'll see it right away when you pull away the trim carpeting... it's the small module (fits in the palm of your hand) with a single bolt through the top of it, connector on the side facing the rear of the vehicle. You'll also see the diagnostic connector hanging nearby.
I doubt it's the fuse... the UPRA gets its power from the 10A IGN 1 fuse, so if it blew a lot of other stuff would be screwed up too. It also gets its power from the 10A PRK/REV fuse, so my next question is are the reverse lights working? No reverse lights, no UPRA.
UPRA also need the RIM working right. Any rim codes?
As for the cost on a UPRA module... we ain't there yet... let's do some testing first, starting with if the reverse lights are working or not, then shorting the diagnostic connector and getting the codes (UPRA light flash sequence). But if the module really is the problem, it's GM #25750800 and it goes for around $150 or so list.
Only on this GREAT forum can you get info like this.
On standard and ESV Escalades, the RPA module is behind the right rear seat. On the EXT Escalade, the RPA module is in a box assembly with the suspension module behind the left rear seat, attached to the seat frame.
I read the part about the two pin diag connector. My 01 DHS has the old ultrasonic module. The connector is there, but with only ONE wire on it. How does this module, 25670327, do a diagnostic ? My reverse sensing stopped working a few weeks ago. Had been working fine for years. Now I only get the red blinking light.
The URPA on my 03 EXT also just quit working. I have checked the sensors and connections and now wanting to try your diagnostic check. I did find some information on how to interpret the lights but not sure how to ground the diagnostic connector.
Can you explain how I do this? I read somewhere just to use a paper clip and just put an end into each socket.
Make sure you have the correct cavities in the connector. You can use a paper clip or short piece of wire with the ends stripped. Often the biggest challenge is getting the jumper connected and watching the light flashes at the same time. Two people may be an advantage for that step.
Well I still don't know what to do on this old style module. If I knew what to check on the 4 sensors I would. Or if there was a quick check on the module, I would do that. I have power as I have the lights, but system quit working about a year ago now. Everything else works on this car.
Thanks
Thanks for clarifying how to ground the diagnostic connector. Tried it out and confirmed my two outside sensors have failed. Makes sense, as the previous owner installed a dual exhaust and the pipes are right underneath the sensors. When I pulled out the sensors it looked like the rubber was overheated and could let water in. The URPA failed after I washed my EXT and rinsed under the bumper. May take them out and see if I can dry them out.
Here is a link to tell you what to do and what the lights mean.
Thanks for diagnostic link. I grounded the single diagnostic pin, and ran the test no problems today. My middle right is failed. Now how do I get that sensor out of the bumper ? Assuming the wiring is good, where do I find another sensor ?
It is possible you just have a connection problem. Some have fixed their problems by zip taping a loose connection.
On the EXT the sensors are fairly easy to get out. If you look on the inside of your bumper, you will see they are held by two clips. You can push on the sensor while holding the clips open, (easier said than done), and the sensor comes right out. There is another clip on the connector to disconnect it.
I haven't got around to replacing mine, but I would expect the dealer can order them. Have heard they are expensive.
I wish this '01 Deville was that easy. The sensors are above the foam barrier at the bottom half of the bumper. I can snake my hand (fingers) up from the bottom of the bumper. I can feel the wiring harness. It did not pull off of the sensor. It seems to be firmly attached.
Either these things "pop out" of the bumper, or some dis-assembly of the bumper seems to be called for. I am currently stumped.
Any body know what the urpa module looks like, the only thing i see in my base 02 is the BCM body control module. Is it under the carpet or something. Im looking directly under the rear passenger bench seat.
It may be on the rear electronics bay which is a large plastic support panel attached to the rear of the back seat bulkhead. Pull the trunk carpet off the back seat area.
Oh wait ok i found it. its actually just two loomed black and green wires with a connector. it actually runs with along side of the larger loom of wires that plug into the BCM module. ive just started running test and i think i found my problem. A badly oxidized pin on the harness side. not the sensor. i pulled it our and its basically powder. no more pin to reach the pin on the sensor. The stealer tells me that if i want a new conector i have to buy the whole thing for all four that goes into the block on the passenger side( for base) they tell me there are two different harnesses. one cost $190 that has a 4 wire connector and the other 125 that has an 8 wire connector, The 4 and 8 wire connectors i speak of plug into a "wall outlet" looking block that sits almost on the inside of the rear passenger side body bumper/molding. he said vin # will decide witch one you need, the 8 pin connector is GM Part# 15092637. ill get back to you guys if i fix it.
FIXED! Its been two years since my urpa last worked.So it turned out that the connections on the left middle and left corner were super oxidized. so instead of buying the new harness, for now i just made my own connections by plunging a wire onto each on of the the pins on the sensor and plugged them with hot glue. Cut off the dead connectors and just twisted the wires together. And BAMM! no error messages.
i guess since the wires of the sensors are just sitting under the bumper for so long, eventually the snow/water salt get to the wire and oxidize the hell out of them. I actually had to snip the wire about 3-4 inches back just to find some clean un-oxidized wire. After going through the system tediously,i feel that there really isnt much room for failure other than the sensor connections themselves.
Have the same problem with my urpa not working and the reverse light not working also. removed back seat to check the fuse and it was blown. replaced the fuse, put car in reverse and it blew the fuse again. does anyone have an idea as to why it keeps blowing the fuse?
It depends on the car, model, and year. Update your profile.
If you have a Cadillac from about 1992 to 2004 you can use the car's built-in Diagnostic Trouble Code system to start diagnosis of the problem. Go up to your car's model Forum and open the sticky post at the top of the main threads list - "How to pull codes". Study and practice, then return to the sticky and open the correct link for your car's year group. That will take you to a Master Index with links to all P,B,C, and U code definitions.
Old post update. I had to replace my sensor that was in the bumper. I got a complete used harness off Ebay. That harness is somewhere in my filled up gararge.
Yeah I got it fixed myself too. Just replaced all the 4 sensors instead of searching for the RPA module. Had ordered 4 sensors from aliexpress for about $40, installed them and first thought it was not working, but took it for a drive and only than it started working, since errors had to be cleared first.
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