02 Protege won't pass emissions

[Falango]

So I've had this car for 6 and a half years, and as several people know, it's been modified. I've had to take the car through emissions testing twice before without any problems at all. This time around though, I have 4 drive cycles that won't complete. Evaporative, Catalyst, EGR, and Oxygen Sensor. Every time I've taken it through, it's been those 4 that reject the car. I have removed all mods from the car that have anything to do with the engine, ecu, exhaust, anything that could interfere with emissions, and all wiring is back to stock as well. I've tested all wiring connections and verified they are correct, and are carrying current. I've gone over the wiring so many times, and driven the car quite a bit each time before taking it to get it tested. I've also got print outs of the drive cycles, followed them and still the same results. I haven't had any CELs come up, car starts and runs absolutely perfect, there are no audible or drivability concerns that would tip off a problem.

I'm curious to see if anyone else has had any issues like this. If these drive cycles don't complete, is it true that I won't get any CELs related to those sensors? For example, if the O2 drive cycle won't complete, will I get a CEL saying the O2 sensor is faulty?

 

[Falango]

Bump, anyone got some input?

 

[Falango]

Bump. Anyone?

 

[Falango]

Bump bump bump

 

[HexRX]

Bump for curiosity!

 

[Falango]

Alright, so I've taken this to Mazda, and had them check the drive cycles and related sensors. All sensors are operating normally (O2, EGR, etc), but the drive cycles aren't even triggering at all. I drove the car 1100km last weekend (Vancouver to Seattle and back twice) which consisted mostly of highway driving, but atleast 2 hours of city driving as well. When we checked the drive cycle status, everything showed incomplete. We thought maybe the ECU is losing power when the car gets shut off, so I drove the car for an hour, followed the Protege drive cycles, came back, checked the status while the car was still running, no changes. We reflashed the ECU, I drove for another 40 minutes, tested again, still no changes. I think it's safe to say it's an electrical problem that is preventing the ECU from running any drive cycles at all, but where it is, no idea. As I said before, no driveability issues at all, no CELs, it runs perfect.

 

[DiS]

that IS very strange. Last time when I've reset my ECU, it took about 20 minutes for 7 out of 8 monitors to set. The 8th one (EVAP) was set the next day... Weird how yours isn't setting.

 

[Falango]

I spoke with someone at a shop that specializes in auto electrical, and got some answers that sound logical. I think there's one test that isn't allowing the rest to begin, so it could be a smaller problem than it seems. It could be one small problem that is triggering the rest. The Protege drive cycles start with a test called Mode 1. It's a simple rev test while the car is not in motion. All other drive cycle tests say that Mode 1 has to finish before any others can begin. It's obvious that Mode 1 is not completing, so all the other drive cycles are locked out. I have noticed from time to time when I start the car, my tach needle sits at 0 for a few seconds, then starts working properly. If I have a bad connection with the RPM signal, this could be triggering a bad reading to the ECU during that test, causing it to fail. This is just an assumption right now, so on Saturday I'll have to check the RPM signal wire out of the ECU. Once I do that, I'll provide an update.

 

[Soccman]

you need to get a drive cycle print out and follow it to the letter and i usually starts off with a cold start and idle for like 2 min.... also if your flashing the ecu everytime you get frustrated that they don't clear your basicly starting from scratch... you need to leave them alone and give it a few days of normal driving before making any diagnosis of the issues your having. I think it would be fair to say that if you still have issues then start digging but don't keep clearing your ecu thats killing you for sure.

 

[Falango]

I've also got print outs of the drive cycles, followed them and still the same results. I haven't had any CELs come up, car starts and runs absolutely perfect, there are no audible or drivability concerns that would tip off a problem.

I drove the car 1100km last weekend (Vancouver to Seattle and back twice) which consisted mostly of highway driving, but atleast 2 hours of city driving as well. When we checked the drive cycle status, everything showed incomplete. We thought maybe the ECU is losing power when the car gets shut off, so I drove the car for an hour, followed the Protege drive cycles, came back, checked the status while the car was still running, no changes. We reflashed the ECU, I drove for another 40 minutes, tested again, still no changes.

To clarify, the reflash was the first time the software has ever been updated. Before then, I had let the car do it's thing for the 1100km trip, and several tanks of gas before that too, no disconnecting the battery, no disconnecting the ECU, etc.

I need to find out what Mode 1 does. It is a simple sit and rev and idle test, but which drive cycle does it verify exactly? Once I find that out, I can hopefully pinpoint the source of the problem. I have noticed from time to time that when I start the car, the tach needle sits at 0 for a few seconds, then jumps to position. It's sporadic and random, doesn't happen every time, maybe 5% of car starts. If there's a bad connection with the RPM readout at the ECU, I'm wondering if that's enough to trigger a problem with the drive cycle, since it needs to read the RPM readout. The RPM position wire was one that was rewired with the piggyback when it was installed, but is now wired back to stock. I checked the voltage on it when the car was running, and it was a steady 6.33-6.35 volts. Revving didn't change the voltage, and I don't have an oscilloscope to read it more accurately.

 

[sselander]

mode 1

The service manual does not go into detail as to exactly what mode 1 does.

--------------------------------------------------
Mode 1 (PCM adaptive memory procedure drive mode)

1. Start the engine and warm up completely.
2. Verify the following conditions and correct if necessary.
All accessory loads (A/C, headlights, blower fan, rear window defroster) are off.
Initial ignition timing and idle speed are within specification.
TEN and GND of DLC are not connected.
3. Perform no load racing at the engine speed
shown in the graph, then idle the engine for more
than 20 seconds after the cooling fan stopped. If
possible, monitor RPM PID for engine speed and
cooling fan status during this procedure

 

[Falango]

Well, this is finally all done! It turned out to be a high idle, due to some buildup in the throttle body. EGR also needed to be replaced, which probably threw the idle out as well. Because the idle was too high, it wouldn't even begin the first test. Got that fixed up, and all was good again!

 

[concept]

Thanks for letting us know. High idle = no mode 1 completion. How many miles are on your engine? I have about 90K and so far, so good.

 

[amikko2001]

how high was your idle? I'm running into exactly the same problem as well. I did a ZE swap and so far have switched back to the American intake and exhaust mani, replaced the o2 sensors, re-hooked up the EGR, just to only have the o2 heater come up as ready...

 

[amikko2001]

how high was your idle? I'm running into exactly the same problem as well. I did a ZE swap and so far have switched back to the American intake and exhaust mani, replaced the o2 sensors, re-hooked up the EGR, just to only have the o2 heater come up as ready...

 

[Falango]

I didn't ask how high it was, but I never had this problem 2 years ago when I last took the car through emissions.

 

[Sport23]

Hmm good info. I never new that high idle would prevent mode 1 from completing, makes sense with what you posted from the service manual. I wonder what the timing and idle speed tolerances are.

The service manual does not go into detail as to exactly what mode 1 does.

--------------------------------------------------
Mode 1 (PCM adaptive memory procedure drive mode)

1. Start the engine and warm up completely.
2. Verify the following conditions and correct if necessary.
• All accessory loads (A/C, headlights, blower fan, rear window defroster) are off.
• Initial ignition timing and idle speed are within specification.
• TEN and GND of DLC are not connected.
3. Perform no load racing at the engine speed
shown in the graph, then idle the engine for more
than 20 seconds after the cooling fan stopped. If
possible, monitor RPM PID for engine speed and
cooling fan status during this procedure