Contour Enthusiasts Group Archives Forums General Troubleshooting CEL...Please Help

I recently scanned the computer and got P0135, P0141, P0155, P0161. I would appreciate any comments on what these fault codes are for and what can be done to fix it, and turn off that damn CEL for good

Try looking in the FAQ section, there is a good write up on CELs and all the codes. These codes are all O2 sensor related for both banks, up and down stream sensors. Check/re-seat all the connectors and if the fault doesn't clear, replace the upstream sensors first.

It is hard to believe that you could have hard circuit faults on all four O2 sensors without having played around under the hood to cause them. You haven't by any chance replaced the bulk of your exhaust system anytime recently, have you?

BTW, here is the link that the last guy refered to:
check engine

The only thing that I have changed is bank 1, sensor 1. I don't know what the deal is. I will check all the connections and such. Anything else it could be?...thanks

Now that I am at work, I have a copy of the real definitions for your DTCs. None of them are O2 sensor circuit faults--they are all O2 heater circuit faults. This makes a big difference in diagnosing the cause. These codes, without the corresponding sensor faults, indicate that your sensor circuits are probably connected and functioning properly. Since the sensor circuit shares the same harness connection as the heater circuit at the sensor, I doubt that you have any connector seating issues.

What does all this mean? Don't replace any more O2 sensors since the sensors are not likely the problem (unless of course the one you replaced resulted in the elimination of one of your DTCs, in which case I'll have to eat the rest of this paragraph ). Most likely, you're looking at a PCM (the powertrain/engine control module) hardware problem. The PCM provides the current to activate the heaters and also monitors the current draw. During each drive cycle, the PCM will turn on the heaters (whether it needs to for emissions or not) and store these codes if the current draw is out of the acceptable range. The PCM does not contain any servicable components, so you would be looking at replacing the whole module. If you are under warranty, by all means get it replaced. If you aren't, you have to ask yourself whether it is worth $400 (you don't even want to know what Ford pays for it ) to turn off your CEL/MIL and have reduced emissions at start-up. If you don't replace the PCM, you run the risk that other parts of the PCM may fail, eventually causing a driveability concern, but I can't quantify that risk (it may be remote).

EDIT: Doh! I just double-checked this site's DTC page and found that they are correct, I just misread them last night.

One of my co-workers also mentioned that it could be the common power source for the heater circuit (the PCM just controls the ground path). This would put the cause somewhere in the harness, but I don't know where that would be in a Contour harness.

I was looking at the schematics in the Chilton manual and all the O2 sensors lead to fuse 13. I look and it is blown. Replace it and it blows again while driving. Maybe there is a short somewhere? This is really starting to annoy me.
Any help is appreciated.

Maybe I should just run illegal emmisions.

Eh???

You need the O2 sensors! PCM uses their data to help regulate the A/F ratio...

PCM will run in limp mode with the permanent CEL!