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    I/M's not setting to READY

    I have a 1996 Mazda Protege, 1.5L, MT 190,000mi.

    I cannot get the I/M's for O2, Catalyst, EGR and EVAP to set to READY after resetting DTC codes. I have driven the vehicle for as much as 6 weeks and they still have not set. I downloaded Mazda Drive Cycle instructions and these drive routines still have not set the I/M's.

    No DTC's are currently present and the ones originally set were self induced by me disconnecting vacuum hoses/sensors while troubleshooting an idling problem. The ECU never set a DTC through normal operation even though the car would occasionally rough idle or die at stop lights.

    BTW, the idling was fixed by new valve cover gasket (leaking oil onto plugs), new plugs, rotor, distributor cap and spark plug wires. The car runs super.

    I just cannot get I/M's to set READY to pass state inspection.

    ANYBODY have a clue? Can the ECU be bad? Can sensors be defective enough to not trigger a DTC but not allow the ECU to reset I/M's to ready?

    Help!

    #2
    I/M Codes

    No...it's not the scanner.

    When you reset any DTC codes stored in the ECM, it also resets the Inspection/Maintenance monitors to NOT READY. A good scanner will also tell you the status of these. Certain I/M's are monitored by the ECU continuously...such as misfire, fuel...others are only reset when certain drive conditions have been met...such as catalyst, O2, EVAP etc.

    The great state of Texas checks these during inspection (so far for certain urban counties only) and if 2 or more are NOT READY...you fail the inspection...which I have done (my daughter took it in before I had a chance to verify the I/M's).

    I have obtained the drive cycle routine for Mazda and have driven the car for some time and 4 I/M's will not set. I know that EVAP and Catalyst are stubborn and it may take very specific conditions for these to set but if I could get the O2 and EGR to set...I could pass inspection.

    The problem is that the car runs great now and no new DTC's are being set. This means that either no sensors or other problems are bad enough to cause a DTC.

    So...now I don't know what it takes to get the I/M's to set to ready. Can a marginal sensor that will not set cause this...can the ECM be bad yet still allow the car to run well...or is it something else like the factory set idle adjustment that I was not supposed to mess with (and did) cause this problem?

    I'm kind of shooting in the dark here. I wish I had the shop manual since Haynes and Chilton don't quite cut it.

    Maybe you can answer another question though. I apparently have two O2 sensors (a 4 wire and a 3 wire). Both Haynes and Chilton say that certain Mazdas have both...one before the catalytic converter and one after to measure converter efficiency. I see two...but one is on the exhaust manifold and the other is on the exhaust pipe just a little further down. Both are before the converter and that best I can tell, I have nothing after the converter. What gives?

    Comment


      #3
      O2 Sensors

      No...I'm in the Houston area.

      I have a 1996 Protege with 190000 miles, MT, 1.5L.

      The 2nd O2 sensor is only about 6 inches below the 1st sensor. No 1 comes off the exhaust manifold (3 wire) just above the manifold/pipe connection. No 2 comes off the exhaust pipe just below the connection before the pipe makes a bend into the converter which is under the floorboard. Everything I read says a two sensor system has one before and one aft of the converter so I am a little mystified.

      I have an Actron scanner. It is menu driven and 1) reads codes, 2) displays MIL light status (to tell you what the light should be doing), 3) erases DTC codes from memory, 4) tells you which I/M's are ready and which are not, 5) device configuration (such as display brightness etc.).

      I bought it at autozone a couple of year ago for $170. Can't imagine not having one now.

      Last year, I had a problem of severe hesitation when you stepped on the accelerator. It would just about die if you leadfooted it. If you accelerated slowly, it would accelerate to about 40 max. Took it to a shop and they gave up after three days. It took me 3 weeks on and off to finally figure out that I had a stuck solenoid on the EGR system that dumped atmospheric through the solenoid into the intake manifold. A shot of WD40 fixed that. But while troubleshooting, I forced some DTC's by unplugging vacuum hoses and sensors. This is when I became aware of the I/M resets, because that happened around inspection time and I had some trouble getting them to reset.

      This time, I had an idling problem caused by oil around the plugs as well as a very worn rotor contact/distributor contacts. Fixing the oil leak, replacing plugs, wires, distributor cap and rotr took care of that. But I messed around with the idle adjustment (which is factory preset) as well as introduced some codes while troubleshooting.

      I had the same problem with the same 4 codes (Catalyst, O2, EVAP, EGR). Three of them cleared in just a couple of days of ordinary driving. The EVAP never cleared. I am aware of the TSB for the EVAP and have not worried about it. I sure wish I had a copy of the bulletin though so I would know what to do.

      This time, I am having a tough time getting any of the I/M's to reset. I have about 12 days left to reinspect the car or face another fee.

      Comment


        #4
        Thanks for your input. I'll check out the TSB's.

        I did check the EGR function and it looks fine. I am going to replace the O2 sensors. The OBDII forum has some articles that recommend replacing them at least at 100,000 miles for 1996 and later; more frequent for earlier cars. It also stated that O2 sensors were responsible for 70% of emission failures. I figure the odds are in my favor to replace them.

        If the O2's don't help...I'll try resetting the codes at autozone with their tool. Beyond that, I hear that Mitsubishi ECM's are failure prone. I believe mine is made by Mitsubishi but so far has not given me any reason to suspect it.

        I probably need to check the water temp sensor since I have read that the system may not go into close loop mode if it is not indicating operating temp.

        I wish I knew more about how the ECM actually uses the inputs. It would also be nice to see real time outputs from the sensors. I think equipment is available to do that but certainly I don't want to spend that kind of money.

        Comment


          #5
          BTW...I did jumper the TEN and GND terminal before setting the idle.

          Comment


            #6
            Tsb 3870

            Technical Service Bulletin 3870 in the FAQ section describes my problem I think. Thanks for the tip!

            Unfortunately I cannot see the LONGFT PID so I will have to assume it is not changing and that the complete system needs to be checked. Not so bad as it sounds since the car is running OK and I did not have any DTC's set before I manually set them.

            I'll start with timing and idle adjustment to ensure these are within spec. If this does not fix the problem (or not out of spec), I'll just start with the things I futzed with during the last bout of troubleshooting. I'm bound to have screwed something up. The front O2 sensor did not help and the rear is much more expensive. I'll hold of on the rear until I've checked everything else first.

            Comment


              #7
              PID's

              You personally and this site have been a BIG help. I am posting at 3 other sites and have received no help.

              My concern is that either the TPS or ISC are the culprits. These are the two things I futzed with besides setting the idle last time. I am going to check them first to make sure they are set to spec as well as idle and timing. It may be an iterative process.

              If all this looks well, then I'll replace the second O2 sensor.

              Do the TPS or ISC effect the SHORTFT or LONGFT directly?

              Where is this info available? Service Manual?

              Comment


                #8
                Final post wrap up.

                I replaced the front O2 sensor yesterday. Problem not solved then however maybe I needed to go through a complete cool down and drive cycle.

                Today, I checked timing and idle. It was 12-14 deg BTDC at 780 rpm which is a little to advanced and a little too high rpm.

                I made sure TEN and GND were shorted in the diagnostic connector and reset the timing to 10 deg BTDC and the idle to 700 rpm...for a manual transmission. Then went for a drive cycle.

                O2 and Catalyst I/M's set to READY. EVAP and EGR have not set however these are the only 2 NOT READY so I should be able to pass inspection.

                I'll give EGR a couple of cool down drive cycles and check again. If it still does not set, I'll check vacuum hose routing, EGR position sensor and EGR valve closer.

                Thanks for all the help.

                Comment


                  #9
                  I have the same exact problem as tnut55. I've got a 96 Protege with 83,000 miles and failed inspection in NY because of the following monitors not being ready: O2, Evap, EGR, and Catalyst. I have No DTC codes and my check engine light is not on (eventhough the light works by passing the power-on check).

                  I'm scratching my head here...I have the same rough-idle-while-stopped-in-Drive problem that a lot of other people here have - my RPM would fluctuate anywhere from 500 to 1100 a few times while sitting at a red light (and of course the car would shake). I tried pulling out the EGR valve and clean it but couldn't get it out...will try again later (how do you guys get a wrench down there?!).

                  Anyway so after reading this thread I tried to adjust timing and idle to factory specs like tnut55 did but don't know how to read the timing marks...

                  I did the generic drive cycle a few times trying to get the monitors to be ready to no avail. Does anyone have a source for the Mazda-specific drive cycle? I would appreciated it if they can post here.

                  Thanks in advance for any suggestions.

                  Comment


                    #10
                    tnut55, I also messed with my car and messed things up. Do you know what I can do from your bad experience? I had high idle in the 2000RPM range. I took the TB off and cleaned it really, really well. I put it back and now it revs past 4000RPM's. It even reaches 5. I looked at all vacuum hoses and connectors and all is well. I even replaced bad vacuum hoses. I gave up and took it to the dealership. The service advisor saw that I knew the lingo and can work on my own car a bit. He suggested before they try anything else that I replace the TB. That afterhe moved the TB screw with no jumpers on the GND & TEN and saw no variation. I told him I had done it with the jumper and that there was a difference but it was next to nothing. I do notice that if I return the throttle by hand where the accelerator linkage goes that it moves back just enough to lower the idle to a reasonable level. However, there's no more the cable adjustment nut will do to keep it there. The lower cable that allows the little wheel to return is already as loose as you can get it. My problem is not rough idle or low idle. It's super duper fast idle. I thought it was electrical but it seems that it's not. I sprayed starter fluid all over the area and nothing ignites and I hear no vacuum hiss. I have the shop manual but after the first few simple checks, it then asks you to disconnect the ECU and connect something called an SST to it. That, I think, is probably the big mult-thousand dollar testing maching at the dealer. That's what I imagine.

                    Comment


                      #11
                      TheMan, I did read the whole thread completely, a few times even. I'm just trying the easiest things first, if they work, no need to go further.

                      So far, adjusting the timing and idle RPM to factory defaults didn't work. I'm going to take off the EGR valve this weekend, then check the O2 sensor, etc...

                      Comment


                        #12
                        My particular problem is solved. If anyone needs to read about it, search for the thread titled " I can't get my idle down"

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