2G 1999 ecu emissions

[azkkr]

just finished the ECU Swapt. I used a 1999 GST. Now The code reader only have 4 incompleted tests. Before it has 5. (Catalyst, Evaporative system, Oxygen sensor, Oxygen sensor heater, and EGR system- NOT Completed). with the new ECU,the O2 Sensor Heater is completed.

Do I need to do something to make the others get completed as well?

P0446 CEL - EVAP Emissions control system vent control circuit malfunction.

 

[toojung2die]

how to do this?

Find the ECU connector pin. http://www.vfaq.com/mods/ecu-harness-2G.html
Connect the positive probe of a voltmeter to the ECU pin and the negative probe to ground. Turn on the ignition but do not start the car. You should read system voltage on the voltmeter (2 volts according to my copy of the service manual but I have a feeling that's a misprint and should read 12 volts). Start the car and when the ECU energizes the solenoid the voltage at the pin will drop to 0 volts because the ECU is grounding that pin. The ECU knows it should read system voltage when the solenoid is inactive and 0 volts when the solenoid is energized. Anything other than these readings under these conditions will seen as a solenoid circuit malfunction.

 

[azkkr]

Find the ECU connector pin. http://www.vfaq.com/mods/ecu-harness-2G.html
Connect the positive probe of a voltmeter to the ECU pin and the negative probe to ground. Turn on the ignition but do not start the car. You should read system voltage on the voltmeter (2 volts according to my copy of the service manual but I have a feeling that's a misprint and should read 12 volts). Start the car and when the ECU energizes the solenoid the voltage at the pin will drop to 0 volts because the ECU is grounding that pin. The ECU knows it should read system voltage when the solenoid is inactive and 0 volts when the solenoid is energized. Anything other than these readings under these conditions will seen as a solenoid circuit malfunction.

Will try it today!!!!! If it doesn't look good, what can be happening? Bad ECU or Short?

 

[toojung2die]

Will try it today!!!!! If it doesn't look good, what can be happening? Bad ECU or Short?

An open circuit is more common than a short circuit. In that case there would be no voltage at the ECU when the car is on but not running. If the voltage readings are correct I would suspect a bad ECU. Do you have your old one to swap back in? You can then compare results with the new and old ECU's.

You said the solenoid clicks rapidly when the car is running. In this case I suspect you'll see the expected voltage changes at the ECU pin. This would mean the circuit is good but the ECU is not sensing the change. It may be a bad ECU. There are a few members on this board that repair ECU's. Bad capacitors and damaged traces are pretty common problems.

 

[azkkr]

An open circuit is more common than a short circuit. In that case there would be no voltage at the ECU when the car is on but not running. If the voltage readings are correct I would suspect a bad ECU. Do you have your old one to swap back in? You can then compare results with the new and old ECU's.

You said the solenoid clicks rapidly when the car is running. In this case I suspect you'll see the expected voltage changes at the ECU pin. This would mean the circuit is good but the ECU is not sensing the change. It may be a bad ECU. There are a few members on this board that repair ECU's. Bad capacitors and damaged traces are pretty common problems.

Yes i do have the old ECU 1996 and swap it last night. The car runs better with it and the is no clicks in the solenoid. Even when idles, you can tell the difference. I get no codes on this one(1996). I will check both today.

With the 99 ecu the car kinds of stutter around 2k rpm and also when it's crussing. This does not happens with the old one.

The reason I want a 98 -99 ecu is to avoid paying $225 every year to the dealer to have the emissioms done. The 1996-1997 ecu reset themself every time the car is turn off. Therefore the monitors are incompleted all the time. This is not a problem with the 98-99. The dealers does the drive cycle using the MUT scanner and do the emissions at the end of the drive cycle without turning the engine off.

 

[toojung2die]

Yes i do have the old ECU 1996 and swap it last night. The car runs better with it and the is no clicks in the solenoid. Even when idles, you can tell the difference. I get no codes on this one(1996). I will check both today.

With the 99 ecu the car kinds of stutter around 2k rpm and also when it's crussing. This does not happens with the old one.

The reason I want a 98 -99 ecu is to avoid paying $225 every year to the dealer to have the emissioms done. The 1996-1997 ecu reset themself every time the car is turn off. Therefore the monitors are incompleted all the time. This is not a problem with the 98-99. The dealers does the drive cycle using the MUT scanner and do the emissions at the end of the drive cycle without turning the engine off.

The CAS is inverted on the '99 ECU and this will cause the roughness you see. You may also get an occasional misfire DTC.
I'm all too familiar with the OBD smog issues you're having. I started a thread three years ago about this problem and it continues to stay active. http://www.dsmtuners.com/forums/showthread.php?t=123736
There's a Wiseman on this board (akdsmer) that has fixed this problem on several DSMs. He has valuable solutions to getting your stock ECU to set the monitors. Search for his posts on this subject.
I got a '95 EPROM ECU and DSMLink last year. All OBD problems are resolved. I can finally pass smog the usual way. The dealers are robbing people to get them a passing smog certificate.

 

[azkkr]

Find the ECU connector pin. http://www.vfaq.com/mods/ecu-harness-2G.html
Connect the positive probe of a voltmeter to the ECU pin and the negative probe to ground. Turn on the ignition but do not start the car. You should read system voltage on the voltmeter (2 volts according to my copy of the service manual but I have a feeling that's a misprint and should read 12 volts). Start the car and when the ECU energizes the solenoid the voltage at the pin will drop to 0 volts because the ECU is grounding that pin. The ECU knows it should read system voltage when the solenoid is inactive and 0 volts when the solenoid is energized. Anything other than these readings under these conditions will seen as a solenoid circuit malfunction.

I just finished the test in both ECU 99 and 96.

1996 ECU
OFF 0.0V
ON ~ 12.5 V
Runing ~ 13.8v

after a minute or so, the ECU grounded the solenoid and the voltage went down to 0.0V and stay there for a while and then came back up to 13.8v. No codes on the reader.


1999 ECU
OFF 0.0V
ON ~12.5V
Runing ~13.8v

the voltage never came down from the 13.8V. Car ran for 5 minutes and a pending code P0446pd came up in the reader.

The engineer from Mitsubishi told me that as long as theree is a code, the EVAP monitor will never clear.

So Do I have a bad ECU?

What about this ?

"Probably not. This from the service manual for P0446:
Solenoid coil surge voltage (system voltage +2V) is not detected when the Evaporative
emission vent solenoid is turned on/off."

I'm getting ~13.8V( almost +2V), isn't this enough????

 

[toojung2die]

So Do I have a bad ECU?

What about this ?

"Probably not. This from the service manual for P0446:
Solenoid coil surge voltage (system voltage +2V) is not detected when the Evaporative
emission vent solenoid is turned on/off."

I'm getting ~13.8V( almost +2V), isn't this enough????

Looks like you have a bad ECU. You see voltage on the meter when the solenoid is not activated. When the ECU activates the solenoid the voltage on the pin drops to 0 volts because the pin is now grounded by the ECU. The ECU 'sees' the voltage at this point because the circuit is now complete. Your tests show that the '99 ECU is not grounding the solenoid pin and completing the circuit so you see a constant voltage on the volt meter. You would get the same test results if the solenoid was bad but in this case you know the solenoid is good because the test with the '96 ECU proves it works. The test results you got with the '96 ECU are normal.

 

[azkkr]

Looks like you have a bad ECU. You see voltage on the meter when the solenoid is not activated. When the ECU activates the solenoid the voltage on the pin drops to 0 volts because the pin is now grounded by the ECU. The ECU 'sees' the voltage at this point because the circuit is now complete. Your tests show that the '99 ECU is not grounding the solenoid pin and completing the circuit so you see a constant voltage on the volt meter. You would get the same test results if the solenoid was bad but in this case you know the solenoid is good because the test with the '96 ECU proves it works. The test results you got with the '96 ECU are normal.

Choices;
1. get another 99 ecu and take my chances
2. e-prom and dsm link
3. pay the dealer $225 every year
4. set the car on fire......

 

[toojung2die]

Choices;
1. get another 99 ecu and take my chances
2. e-prom and dsm link
3. pay the dealer $225 every year
4. set the car on fire......

5. '95 EPROM ECU with a Keydiver chip and AFC.

I almost went this route but at the time Keydiver chips did not have a fix for the "MIL Bug" in '95 EPROM ECU's. They now have a fix for this bug in the chip code . BTW, last year my dealer charged me $305 to set the monitors and get a passing smog certificate. I call it legal extortion. They know there's a problem but refuse to acknowledge it because it makes them $$$.

 

[azkkr]

5. '95 EPROM ECU with a Keydiver chip and AFC.

I almost went this route but at the time Keydiver chips did not have a fix for the "MIL Bug" in '95 EPROM ECU's. They now have a fix for this bug in the chip code . BTW, last year my dealer charged me $305 to set the monitors and get a passing smog certificate. I call it legal extortion. They know there's a problem but refuse to acknowledge it because it makes them $$$.

where and how to get this set up? How much wll it cost me?

 

[toojung2die]

where and how to get this set up? How much wll it cost me?

Now you're asking to be spoon-fed. Get the EPROM ECU used. Buy one already socketed or get it socketed. Get the AFC new or buy one of the many used ones being sold here or on eBay. Decide what size fuel injectors you want to use and get a Keydiver chip burned for your application. If DSMLink is out of reach of your budget this another way to go.
http://www.dsmchips.com/
http://www.dsmtuners.com/parts/product_info.php?cPath=3_175_66&products_id=649
There's one other long-shot. Take your car and the failing smog test to your state's emission control lab or wherever they handle grievances. Point out your car is on the list of cars that have problems with OBD-II. If they're real nice you'll get a waiver.

 

[azkkr]

Now you're asking to be spoon-fed. Get the EPROM ECU used. Buy one already socketed or get it socketed. Get the AFC new or buy one of the many used ones being sold here or on eBay. Decide what size fuel injectors you want to use and get a Keydiver chip burned for your application. If DSMLink is out of reach of your budget this another way to go.
http://www.dsmchips.com/
http://www.dsmtuners.com/parts/product_info.php?cPath=3_175_66&products_id=649
There's one other long-shot. Take your car and the failing smog test to your state's emission control lab or wherever they handle grievances. Point out your car is on the list of cars that have problems with OBD-II. If they're real nice you'll get a waiver.

http://autocenter.weber.edu/OBD-CH/documents/newdocuments/Mitsubishi/tsb0313005.pdf

I will take your advice and go to see if I can get the waiver before going crazy and spend all this money.

thanks for all your help.