Cadillac Powertrain Control Module (PCM) Tuning Discussion, 93 Eldo Northstar Map Sensor? in Cadillac Engine Discussion; Does anyone know any reasons for an open map sensor code and intermitant map Ive replaced the map sensor twice ...
Does anyone know any reasons for an open map sensor code and intermitant map Ive replaced the map sensor twice and just replaced the connector and wires. It only starts stalling and sputtering when driving around town (stop and go) it get hot is what i figure, but once i get on the freeway it stops and runs normal, then starts again once in town. Any ideas will help.
You'll need to get some sort of simple scan too to read what the MAP value is reading.
Low cost? ELM, go to Scantools.net or MXScan. My $ is to get MXScan (I will be ordering mine soon!)
High cost? AutoTap
Look for a vacuum leak around it. I verified my MAP by connecting a hand held vacuum pump to the nipple of the sensor and pumped it up reading the PCM value on my Laptop with my ELM/Scantools.net scanner. Worked well, was dead on. But I sprayed some PB Blaster around it and I got PB Blaster smell out the tail pipe, I had a seal leak. I just put some red RTV on the seal and pushed it in, sprayed again after 2 days of sitting to ensure it was sealed up and no smell.
I don't have a FSM, but I would go talk to the N* Tech forum and ask for someone to post the troubleshooting on it. If sensor ok, and no vacuum leak, chase the wires all the way to the PCM, ensure they are good and NO breaks or rubbed off insulation. IF that isn't it, then PCM. I doubt PCM, those issues are rare. Don't rush to it, check it. If you can find another car that uses that MAP test on another car. Go to ACDELCO.com, and lookup the sensor, then put in that part number in the VEHICLE LIST and see where the part is used. Then see if a buddy has the same car....
Had the exact same problem on my 93 Eldo Northstar. Also replaced the map sensor but still the same codes. Problem was the replacement MAP sensor, an off brand, wasn't cutting it- it wouldn't provide a steady reading to the PCM and often times, it would just shut down altogether, causing the PCM to shut down the injectors, leading to a stall. Problem was solved by replacing the new MAP sensor with an AC Delco brand- it cost a lot more than the off brand but you know what they say- "You get what you pay for..." Replace the MAP sensor with the OEM replacement and you should be good to go.