Contour Enthusiasts Group Archives Forums General Troubleshooting What Else - CEL (Check Engine Light)

Okay, this is my first post here, but definately not my first visit. I have reviewed the FAQ and found them very helpful in diagnosing some of the problems I've encountered with my 95' contour.

So the CEL blinks intermittently usually after 20-30 minutes of city driving. I ran the codes using the info provided in the FAQ (volt meter option) and came back with codes 179 and 189, but I suspect I just missed a blip on the first one, so in reality it should be the 189 code. Now the list of errors on the FAQ indicate the 189 code is an O2 sensor, but could I get verification from you guys that it is in fact a 02 sensor for the 4cyl 95 contour with the ATX.

I Checked with Part Source, and they say that there is only the one O2 sensor, is this true for the 4cyl?

**I had the MAF changed about a year ago prior to the CEL issue
**I changed the oil, I heard that might trigger the problem.
**I changed the Thermostat, was getting higher temps and thought it might have something to do with the CEL.
**I changed the O2 sensor, and the day after the CEL came back.

Now I saw another post where a person suggested cleaning throttle bodies and upper intakes and lower intakes. This seems like it could cost alot of money if I F*ck up. I also looked for a Haynes manual for my car, and PartSource doesn't have any in stock.

Any Idea what I should do, besides selling the car????

Thanks,
T-Bone

189 Fuel system was lean at part throttle - Left or Front HO2S - Fuel control

There are two O2's but only the top one on the exhaust manifold is fuel control. This code is for data from the O2, that does not mean it is bad.


Common reasons for this can be a bad O2, low fuel pressure, or excess unmetered air.

Logicaly, you should probably look for air leaks. these can be in the plenum between the MAF and TB, or vacuum leaks.

The most common vacuum leak tends to be in the PCV system. A short rubber hose between the PCV vacuum pipe and the PCV valve fails due to oil and heat. This is under the exhaust manifold on the PCV oil baffle and not the easiest thing to get to.

Do you have a 4cyl? 95 zetecs (4cyl) only have one o2 sensor.

My '95 GL's CEL light comes on because the insulation is gone on the harness leading to the coolant temperature sensor. I have to re-position the wires so that they don't touch and everything is fine. I know it is this problem because it makes the electric fan on the radiator come on. This morning the fan and CEL came on as soon as I cranked the engine and it was 34 degrees outside.... I don't think the engine was hot yet! I moved the wires so they wouldn't touch and the fan stopped and the CEL went off.

DB

So now I have taken it to the Mechanic, and he has replaced the fan activation switch and the temperature sending sensor (what ever it is called -- under thermostat). The fan apparently wasn't coming on so they replaced those things. The fan now activates but only when it gets to the middle of the L of NORMAL.... which I think is too high, and higher than when I first purchased the car. The Thermostat that I bought for the car was a 195 which should be good all year round. I also replaced the O2 sensor earlier....

When the Oil Filler cap is removed (4cyl) there is a definate rush of air (vacuum sound) so tonight I am replacing the PCV. I think that might be the problem, wish me luck.... I might also replace the cap on the Rad Overflow tank, I have heard a few people in here mention that....

thanks dbbubba for the tip about the insulation, I will look into that while I am down there...

Any other ideas...

TBone....669

The Zetec has a two stage cooling fan.

The only way you are going to find out if the "L" trip point is right or wrong is to actually measure the temperature of the cooling system. Santa broght me a neat little IR thermometer from Sears (about $50) so I can now measure the exact temperature of things such as the water outlet housing without actually touching them. Pretty cool little toy.

Low speed should kick on around 210F, high speed should come in about 220F.

BTW, there is no "fan activation switch" on this car. There is an ECT (Engine Coolant Temp) sensor that tells the computer what the operating temp of the system is at. The dash guage is run by a separate, different sensor.

Steve

You actually touched on something I was noticing - I think that I am only getting the High speed fan kicking in.

I don't have the little toy you are refering to, I am new to the whole "garage thing" but slowly aquiring the goodies. My neighbor has one I think though, so I might harass him.

Anyway, thanks to the FAQ and HOW TO sections on this FABULOUS site I was able to "easily" change the PCV. I wonder how anyone could like working on these things... Contours that is... Maybe I am just a bit bitter at the wasted 3 hours.

So Now I can add the PCV to the new parts list.... I haven't seen the CEL since the last Friday (after the mechanic first looked at it), but the Temp gauge going all the way to the L really un-nerves me.... What eles could it be... Shouldn't the new ECT control both of the two speeds of the fan?

New O2 sensor, and Thermostat plus heat in the car means I am getting coolant flow right.... So I shouldn't be looking at my pump or anything like that right.

I think the new PCV has improved my idle--moderately, but little else. I don't think I have any vacuum leaks but even if I did it would really only affect my idle not my temp right?

10 degrees doesn't seem like much of a difference for the low and high fan.... But the temp needle passes right on by N O R M and A before the high speed fan kicks in... so maybe the low speed fan actuation isn't occuring??? How to know/ test???

Thanks again for the comments and the place to vent....

TBone...669

The ECT serves as the only input to the PCM for monitoring coolant temperature.

At the first trip point, the PCM energizes the low-speed fan relay located in the engine compartment fusebox. This relay applies power to the fan dropping resistor (located at the bottom driver's side of radiator shroud) and energizes the fan with a reduced voltage.

If the PCM sees the temperture hit the second trip point, it energizes the high speed fan relay with applies full power to the fan, bypassing the low speed circuit.

Interestingly enough, there is a test documented in the 95 service PCED in the PCM Quick Test procedure for the 95 that will test the LFC and HFC circuits., allowing you to toggle the high and low speed fans circuits on or off. If you have the service CD, it is in Section 5A.

The procedure, cut and pasted, is as follows:

Output State Diagnostic Test Mode (DTM)

The Output State DTM aids in servicing output actuators associated with the EEC system. It enables the technician to energize and de-energize most of the system output actuators on command. This DTM is entered after all DTCs have been received from Key On Engine Off and Continuous Testing. At this time, leave Self-Test activated and depress the throttle. Each time the throttle is depressed, the output actuators will change state from energized to de-energized or from de-energized to energized.

1. Enter Self-Test.

2. DTC Output Ends.

3. Do Brief WOT.

4. EEC Output To Actuators Energized.

5. Do Brief WOT.

6. EEC Output To Actuators De-Energized.

7. For vehicles with LFC and HFC circuits:
To cycle the LFC and HFC outputs after code output ends, depress and hold throttle. For LFC, wait until the MIL flashes once (10 seconds). For HFC, wait until MIL flashes twice (15 seconds). Release throttle. The LFC or HFC output is now on (to cycle output off, depress and release throttle).

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Hope this helps.

Steve

Steve

Only the High Speed fan is working. The low speed isn't.