Northstar Engines and System Technical Discussion Discussion, Pcm Gone Loco? in Cadillac Engine Discussion; Recently my 93 Touring coupe N* began an occasional engine quit for about 1 or 2 turns then back ok. ...
- 07-04-05 09:27 PM #1Cadillac Owners Fanatic
- Automobile(s): 88 CPE DV, 93 ELDO TOURING
- Join Date
- Apr 2004
- ZEBULON, NC
Pcm Gone Loco?
Recently my 93 Touring coupe N* began an occasional engine quit for about 1 or 2 turns then back ok. Then it became more frequent; once a trip over 25 miles. once a week, then twice, then every day, then last trip several times in a mile. I got it home, but successive starts got worse. It ran terrible with blue smoke out one pipe, and the smell of raw fuel. Warnings poped up so fast I couldn't write them down. I turned it off for a 10 or 15 seconds then turned the key on. It threw up stop engine but it wasn't running. then "lost PCM data". It hasn't run since. My wiring checks turned up a twisted and taped joint on the temp sensor plug, hence the intermittent temp sensor code, and a burned wire where the harness touched the EGR pipe. Now it won't start. It fires rythmically but wont stay running like it did before. When the key is turned on, the low speed fan relay pulls in, and you can here the other fan relays chattering. There is 12v at the fuel pump relay with it removed, but inserting the relay pulls it to 0v. If I jump the fuel pump it runs at 40 psi but the diagnostic code PO10 (fuel pump feed back) stays 0. The TPI at code PO1 stays at -13 even though the voltage at pcm pin B15 goes from 1 to 4 volts. The manifold air temp says -40, but the coolant says 37. The only codes now are TO72, and SO44. The book says if the fuel pump relay circuit PCM A15 doesn't go high for 2 seconds at key on, the PCM is bad. Anyone have any ideas?