: Help!! Set off several codes on my 94 FWB!

04-05-13, 06:32 AM
Hey guys it's been awhile, more like forever, but I need your help! I was in the process in trying to remove one of the O2 sensors from the Caddy, and for one thing, it's seriously stuck frozen inside the exhaust pipe. So I tried heating the car up as hot as possible, not realizing that the O2 sensor was still connected to the connector( I thought I disconnected it) that goes to the computer and several other important functions.

Well as I was trying to get an 7/8 box wrench over the sensor onto the nut to break it loose, I guess somehow there was a very small split in the wires, or I could of did it by slipping the wrench over the wires, and the car immediately turned off! Something got shorted out, I saw a quick spark.

Well I started the car again, but now the Service Engine Soon light came on, and I can hear the PCM or something running very loud, almost like a vacuum cleaner. As I checked for codes, I found several of them. All are related to the Emission system. Here are the codes.

"00" PCM codes

DTC 26 EVAP canister purge circuit.
DTC 27 EGR circuit
DTC 29 AIR injection circuit
DTC 48 MAF Sensor circuit

"01" CCM

DTC 143
DTC 144

I don't know what exactly these codes are for, even the maintenance manual doesn't say what the CCM DTC 143-144 codes are since it doesn't list them.

Even with these codes and the engine light being on, the car starts and drives perfectly fine, like nothing happened. So I don't know if serious damage occurred to these sensors or the PCM itself, or I just need to clear the codes somehow because of the short that the car automatically protects itself by shutting off thus setting codes that need to be cleared.

I have a scan tool that is both a OBD1/OB2 scanner, and for some reason my scanner wont communicate with my car, I don't think it's supported unfortunately:nono: But from I read in the manual, it says that hard codes need to deleted with a scan tool, disconnecting the battery wont work. I tried doing that, and it didn't work so it's true.

I'm so screwed, the car needs to be smogged in a month and now this happens! The car has been great ever since, I have had zero problems with my Fleetwood over the years, and all because of a stupid mistake by me, I just put myself in an even more difficult position. If anyone knows what is wrong, and what I can do, please let me know! I really appreciate it thanks so much!!!

04-05-13, 06:44 AM
Are the codes current or history?

04-05-13, 08:48 AM
the ones starting with 1 are history codes I believe, so the two under 01 COM are both history.

Hopefully the PCM isn't fried from that spark you saw? Not sure, but it doesn't sound good. Did you fix the short?

04-05-13, 09:42 AM
did you check your fuses? Under the hood and under the dash? I would think the whole emissions circuit is under one or two fuses.

04-05-13, 10:10 AM
All is well now :thumbsup: As I was reading the Fleetwood maintenance manual which I call the "Bible" literally since it has thousands of pages, and weighs like 5lbs haha. It never occurred to me to check the fuses, just didn't think of it since I thought of the problem being more catastrophic. After further investigation, the emission fault codes that became present, was all due to a blown fuse! The EVAP, EGR, MAF sensors and solenoids are all routed to the same fuse link located under the hood in the black box. So when the short happened, the sensors and solenoids stopped working.

After replacing the blown fuse, everything went back to normal, and now the Engine light is off! :) And here I thought it was going to be something major, I'm so happy yet still a little shaken up by it all.

Thanks Caddy Folks!


Now if anyone could give me advice on how in the heck are you able to the remove the Passenger side O2 sensor? There's barely enough room to fit your hands in the tight spot, and using a wrench simply wont work because of the lack of clearance on both sides of the exhaust pipe. Using a "Shorty" wont cut it either, you need some leverage to loosen the sensor up.

04-05-13, 10:56 AM
This will let you get the O2 out on the LT1 cars.