At my wit's end !
#1
11-15-2016, 11:08 AM
At my wit's end !
I'm hoping someone can possibly help.Bear with me this may be a little long winded.
A couple of weeks ago my, 2002, 3.0 V6 Shogun Sport ( The UK version of the Montero) threw a code , the innocuous P0125. So like lots of others who've had this code I changed the following
Coolant Temp Sensor ( Denso)
Viscous Fan
Topped Up Coolant
It's had a new radiator not so long ago and gets upto temperature so I can rule out the thermostat.
I also having got a live data reading changed the drivers side ( my car is right hand drive ) O2 sensor, Bank 1 Sensor 1. ( Black plug for reference purposes)
It was reading 0.00 Mv while all the others flucated.
I checked the voltage at the coolant temp sensor which was working fine.
But STILL the code remains.
Also the other day it lost power briefly then cleared itself and runs fine.
I checked the codes again yesterday and along with code P0125 was P0173 . Ive checked the MAF sensor and it appears to be fine , voltage fluctuations were normal. I've been told it could be a intake vacuum leak???
I've been for an extended drive and P0173 has not reappeared but P0125 remains.
Has anybody had any success in fixing this problem ? As you can see I've tried everything apart from replacing the vacuum hoses which is my next job.
I really am at my wit's end trying to solve this problem or simply living with it.
I've trawled through literally hundreds of posts and threads on Various sites but can't seem to find anything positive in regards to fixing it, most are very vague.
I should add the cars drives fine no smell of unburnt Petrol no significant change in MPG.
It ran faultlessly for 2000 miles before this and has one of the best service history of any car I've ever seen.
Many thanks
Paul
A couple of weeks ago my, 2002, 3.0 V6 Shogun Sport ( The UK version of the Montero) threw a code , the innocuous P0125. So like lots of others who've had this code I changed the following
Coolant Temp Sensor ( Denso)
Viscous Fan
Topped Up Coolant
It's had a new radiator not so long ago and gets upto temperature so I can rule out the thermostat.
I also having got a live data reading changed the drivers side ( my car is right hand drive ) O2 sensor, Bank 1 Sensor 1. ( Black plug for reference purposes)
It was reading 0.00 Mv while all the others flucated.
I checked the voltage at the coolant temp sensor which was working fine.
But STILL the code remains.
Also the other day it lost power briefly then cleared itself and runs fine.
I checked the codes again yesterday and along with code P0125 was P0173 . Ive checked the MAF sensor and it appears to be fine , voltage fluctuations were normal. I've been told it could be a intake vacuum leak???
I've been for an extended drive and P0173 has not reappeared but P0125 remains.
Has anybody had any success in fixing this problem ? As you can see I've tried everything apart from replacing the vacuum hoses which is my next job.
I really am at my wit's end trying to solve this problem or simply living with it.
I've trawled through literally hundreds of posts and threads on Various sites but can't seem to find anything positive in regards to fixing it, most are very vague.
I should add the cars drives fine no smell of unburnt Petrol no significant change in MPG.
It ran faultlessly for 2000 miles before this and has one of the best service history of any car I've ever seen.
Many thanks
Paul
Last edited by Marso70; 11-15-2016 at 11:58 AM.
#2
11-15-2016, 01:46 PM
Ok, time to stop, breath in deeply and exhale slowly 
I think you are too worked up about it. Don't replace any more part until you actually figure out what is going on first.
Item #1 on your "To Do" list is to get the Freeze Frame data (FF) for the codes you pulled. I'm pretty certain that both codes related. On the FF data you need to check what your Fuel Trims are. Look for Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). These will have ether "+" or "-" X% values. Look for the data for both Bank 1 and 2 and post the values. Also, since you are having P0125, post the engine temp value form FF data, RPM and engine load if you are able to pull it. Do not rely on the data on the temp gauge on the instrument cluster - the signal is coming form separate sensors.
BTW, I don't want to upset you too much, but P0125 code means that the engine does now warm up sufficiently. Therefore replacing the fan was not needed, unless it was actually broken. Also, you can't rule out the thermostat (it could be stuck open), but let's get down to the numbers from your codes first before making that call.
I think you are too worked up about it. Don't replace any more part until you actually figure out what is going on first.
Item #1 on your "To Do" list is to get the Freeze Frame data (FF) for the codes you pulled. I'm pretty certain that both codes related. On the FF data you need to check what your Fuel Trims are. Look for Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). These will have ether "+" or "-" X% values. Look for the data for both Bank 1 and 2 and post the values. Also, since you are having P0125, post the engine temp value form FF data, RPM and engine load if you are able to pull it. Do not rely on the data on the temp gauge on the instrument cluster - the signal is coming form separate sensors.
BTW, I don't want to upset you too much, but P0125 code means that the engine does now warm up sufficiently. Therefore replacing the fan was not needed, unless it was actually broken. Also, you can't rule out the thermostat (it could be stuck open), but let's get down to the numbers from your codes first before making that call.
#3
11-15-2016, 03:06 PM
Ok, time to stop, breath in deeply and exhale slowly
I think you are too worked up about it. Don't replace any more part until you actually figure out what is going on first.
Item #1 on your "To Do" list is to get the Freeze Frame data (FF) for the codes you pulled. I'm pretty certain that both codes related. On the FF data you need to check what your Fuel Trims are. Look for Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). These will have ether "+" or "-" X% values. Look for the data for both Bank 1 and 2 and post the values. Also, since you are having P0125, post the engine temp value form FF data, RPM and engine load if you are able to pull it. Do not rely on the data on the temp gauge on the instrument cluster - the signal is coming form separate sensors.
BTW, I don't want to upset you too much, but P0125 code means that the engine does now warm up sufficiently. Therefore replacing the fan was not needed, unless it was actually broken. Also, you can't rule out the thermostat (it could be stuck open), but let's get down to the numbers from your codes first before making that call.
I think you are too worked up about it. Don't replace any more part until you actually figure out what is going on first.
Item #1 on your "To Do" list is to get the Freeze Frame data (FF) for the codes you pulled. I'm pretty certain that both codes related. On the FF data you need to check what your Fuel Trims are. Look for Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). These will have ether "+" or "-" X% values. Look for the data for both Bank 1 and 2 and post the values. Also, since you are having P0125, post the engine temp value form FF data, RPM and engine load if you are able to pull it. Do not rely on the data on the temp gauge on the instrument cluster - the signal is coming form separate sensors.
BTW, I don't want to upset you too much, but P0125 code means that the engine does now warm up sufficiently. Therefore replacing the fan was not needed, unless it was actually broken. Also, you can't rule out the thermostat (it could be stuck open), but let's get down to the numbers from your codes first before making that call.
I have some freeze frame data for you.
On the 29th October ( Prior to changing the Oxygen sensor) it produced the following readings
DTCFRZR P0125
FUELSYST 1 CL
FUELSYST2 CL
LOAD PCT 44.3
ETC- 201F
SHRTFT1 % 3.9
LONGFT1 %0.0
SHRTFT2 %25.0
LONG FT2 %0.00
RPM 2438
VSS MPH 62
Yesterday ( 14/11/2016). it posted these readings ( post drivers side based on a right hand drive car Oxygen sensor replaced, black plug )
ETC 203F
SHRTFT1 %1.6
LONGFT1 %2.3
SHRTFT2 % 25
LONGFT2 %12.5
RPM 1961
VSS MPH 43
Obviously I don't want to spend or waste any more money and at worst case I'm prepared to live with the fault. But ideally I'd like to fix it if i can.
Many thanks
Paul
#4
11-15-2016, 03:22 PM
Although I've not ruled out the thermostat as that's not been changed, the car gets up to temp nice and quickly and doesn't run cool or overheat so I would presume the thermostat is functioning correctly?
#5
11-15-2016, 04:33 PM
No worries - I just thought to poke at you a little since you did sound very flustered
The good news is that the engine temp that PCM receives is in the normal range. That means the cooling system is operating just as its suppose to.
The second set of data does not show FUELSYS CL on ether Bank 1 or 2. My guess is that this is an indication of engine not running in Closed Loop and that is the trigger for P0125.
The trigger for P0173 is the fuel trims. The issue you have with the fuel trims is the Bank 2. In both pre- and post-O2 sensor replacement your Short Term Fuel trims on Bank 2 are 25%. In the second set you have an additional 12.5% Long Term FT. This all means that PCM is metering 37.5% more fuel that it would expect to meter based on the input from the MAF, MAP, and readings from O2 sensors. This is the trigger for PCM to set the CEL code. On one hand, the fact that the error is limited to only one bank is good - it rules out a vacuum leak prior to the throttle body, bad MAF and a fuel pump/fuel filter issues. In all those cases you'd have similar (high) fuel trims on both banks.
Now that we are limited to an error on one bank ( I believe this would be a passenger side on the British version) we need to figure out what causes it. You still can't rule out a vacuum leak, but it will have to be happening only on one bank. It is hard to imaging this happening, unless you have a plenum gasket that had failed right at the intake to plenum connection. You can test this by running the engine (at idle) and spraying a small amount of propane or starter fluid right around the intake area right between the cylinders). If the engine suddenly revs up - you found a vacuum leak.
A vacuum leak on one side can be coming form a bad o-ring on one of the fuel injectors on that bank.
You may also have a bad vacuum hose, but my bet is that it would cause both banks to go high on the fuel trims by the similar amount.
Another possible issue is a bad fuel injector. One of the fuel injectors may have failed or become clogged and not delivering the fuel amount that PCM wants to. This is causing the PCM to compensate by calling more and more fuel delivery. When the "extra" fuel amount is high enough, PCM "says" - there is some problem here and sets the error code. Not sure how you can test fuel injectors without specialized equipment. You at least need a fuel injector test light to do this. The issue can be a bad injector or a problem with wiring to any of the injectors on Bank 2, so you have to check/test both.
I hope this gives you some direction to follow. Don't despair - I'm sure it is fixable
The good news is that the engine temp that PCM receives is in the normal range. That means the cooling system is operating just as its suppose to.
The second set of data does not show FUELSYS CL on ether Bank 1 or 2. My guess is that this is an indication of engine not running in Closed Loop and that is the trigger for P0125.
The trigger for P0173 is the fuel trims. The issue you have with the fuel trims is the Bank 2. In both pre- and post-O2 sensor replacement your Short Term Fuel trims on Bank 2 are 25%. In the second set you have an additional 12.5% Long Term FT. This all means that PCM is metering 37.5% more fuel that it would expect to meter based on the input from the MAF, MAP, and readings from O2 sensors. This is the trigger for PCM to set the CEL code. On one hand, the fact that the error is limited to only one bank is good - it rules out a vacuum leak prior to the throttle body, bad MAF and a fuel pump/fuel filter issues. In all those cases you'd have similar (high) fuel trims on both banks.
Now that we are limited to an error on one bank ( I believe this would be a passenger side on the British version) we need to figure out what causes it. You still can't rule out a vacuum leak, but it will have to be happening only on one bank. It is hard to imaging this happening, unless you have a plenum gasket that had failed right at the intake to plenum connection. You can test this by running the engine (at idle) and spraying a small amount of propane or starter fluid right around the intake area right between the cylinders). If the engine suddenly revs up - you found a vacuum leak.
A vacuum leak on one side can be coming form a bad o-ring on one of the fuel injectors on that bank.
You may also have a bad vacuum hose, but my bet is that it would cause both banks to go high on the fuel trims by the similar amount.
Another possible issue is a bad fuel injector. One of the fuel injectors may have failed or become clogged and not delivering the fuel amount that PCM wants to. This is causing the PCM to compensate by calling more and more fuel delivery. When the "extra" fuel amount is high enough, PCM "says" - there is some problem here and sets the error code. Not sure how you can test fuel injectors without specialized equipment. You at least need a fuel injector test light to do this. The issue can be a bad injector or a problem with wiring to any of the injectors on Bank 2, so you have to check/test both.
I hope this gives you some direction to follow. Don't despair - I'm sure it is fixable
#6
11-15-2016, 06:03 PM
Ok, time to stop, breath in deeply and exhale slowly
I think you are too worked up about it. Don't replace any more part until you actually figure out what is going on first.
Item #1 on your "To Do" list is to get the Freeze Frame data (FF) for the codes you pulled. I'm pretty certain that both codes related. On the FF data you need to check what your Fuel Trims are. Look for Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). These will have ether "+" or "-" X% values. Look for the data for both Bank 1 and 2 and post the values. Also, since you are having P0125, post the engine temp value form FF data, RPM and engine load if you are able to pull it. Do not rely on the data on the temp gauge on the instrument cluster - the signal is coming form separate sensors.
BTW, I don't want to upset you too much, but P0125 code means that the engine does now warm up sufficiently. Therefore replacing the fan was not needed, unless it was actually broken. Also, you can't rule out the thermostat (it could be stuck open), but let's get down to the numbers from your codes first before making that call.
I think you are too worked up about it. Don't replace any more part until you actually figure out what is going on first.
Item #1 on your "To Do" list is to get the Freeze Frame data (FF) for the codes you pulled. I'm pretty certain that both codes related. On the FF data you need to check what your Fuel Trims are. Look for Short Term Fuel Trim (STFT) and Long Term Fuel Trim (LTFT). These will have ether "+" or "-" X% values. Look for the data for both Bank 1 and 2 and post the values. Also, since you are having P0125, post the engine temp value form FF data, RPM and engine load if you are able to pull it. Do not rely on the data on the temp gauge on the instrument cluster - the signal is coming form separate sensors.
BTW, I don't want to upset you too much, but P0125 code means that the engine does now warm up sufficiently. Therefore replacing the fan was not needed, unless it was actually broken. Also, you can't rule out the thermostat (it could be stuck open), but let's get down to the numbers from your codes first before making that call.
No worries - I just thought to poke at you a little since you did sound very flustered
The good news is that the engine temp that PCM receives is in the normal range. That means the cooling system is operating just as its suppose to.
The second set of data does not show FUELSYS CL on ether Bank 1 or 2. My guess is that this is an indication of engine not running in Closed Loop and that is the trigger for P0125.
The trigger for P0173 is the fuel trims. The issue you have with the fuel trims is the Bank 2. In both pre- and post-O2 sensor replacement your Short Term Fuel trims on Bank 2 are 25%. In the second set you have an additional 12.5% Long Term FT. This all means that PCM is metering 37.5% more fuel that it would expect to meter based on the input from the MAF, MAP, and readings from O2 sensors. This is the trigger for PCM to set the CEL code. On one hand, the fact that the error is limited to only one bank is good - it rules out a vacuum leak prior to the throttle body, bad MAF and a fuel pump/fuel filter issues. In all those cases you'd have similar (high) fuel trims on both banks.
Now that we are limited to an error on one bank ( I believe this would be a passenger side on the British version) we need to figure out what causes it. You still can't rule out a vacuum leak, but it will have to be happening only on one bank. It is hard to imaging this happening, unless you have a plenum gasket that had failed right at the intake to plenum connection. You can test this by running the engine (at idle) and spraying a small amount of propane or starter fluid right around the intake area right between the cylinders). If the engine suddenly revs up - you found a vacuum leak.
A vacuum leak on one side can be coming form a bad o-ring on one of the fuel injectors on that bank.
You may also have a bad vacuum hose, but my bet is that it would cause both banks to go high on the fuel trims by the similar amount.
Another possible issue is a bad fuel injector. One of the fuel injectors may have failed or become clogged and not delivering the fuel amount that PCM wants to. This is causing the PCM to compensate by calling more and more fuel delivery. When the "extra" fuel amount is high enough, PCM "says" - there is some problem here and sets the error code. Not sure how you can test fuel injectors without specialized equipment. You at least need a fuel injector test light to do this. The issue can be a bad injector or a problem with wiring to any of the injectors on Bank 2, so you have to check/test both.
I hope this gives you some direction to follow. Don't despair - I'm sure it is fixable
The good news is that the engine temp that PCM receives is in the normal range. That means the cooling system is operating just as its suppose to.
The second set of data does not show FUELSYS CL on ether Bank 1 or 2. My guess is that this is an indication of engine not running in Closed Loop and that is the trigger for P0125.
The trigger for P0173 is the fuel trims. The issue you have with the fuel trims is the Bank 2. In both pre- and post-O2 sensor replacement your Short Term Fuel trims on Bank 2 are 25%. In the second set you have an additional 12.5% Long Term FT. This all means that PCM is metering 37.5% more fuel that it would expect to meter based on the input from the MAF, MAP, and readings from O2 sensors. This is the trigger for PCM to set the CEL code. On one hand, the fact that the error is limited to only one bank is good - it rules out a vacuum leak prior to the throttle body, bad MAF and a fuel pump/fuel filter issues. In all those cases you'd have similar (high) fuel trims on both banks.
Now that we are limited to an error on one bank ( I believe this would be a passenger side on the British version) we need to figure out what causes it. You still can't rule out a vacuum leak, but it will have to be happening only on one bank. It is hard to imaging this happening, unless you have a plenum gasket that had failed right at the intake to plenum connection. You can test this by running the engine (at idle) and spraying a small amount of propane or starter fluid right around the intake area right between the cylinders). If the engine suddenly revs up - you found a vacuum leak.
A vacuum leak on one side can be coming form a bad o-ring on one of the fuel injectors on that bank.
You may also have a bad vacuum hose, but my bet is that it would cause both banks to go high on the fuel trims by the similar amount.
Another possible issue is a bad fuel injector. One of the fuel injectors may have failed or become clogged and not delivering the fuel amount that PCM wants to. This is causing the PCM to compensate by calling more and more fuel delivery. When the "extra" fuel amount is high enough, PCM "says" - there is some problem here and sets the error code. Not sure how you can test fuel injectors without specialized equipment. You at least need a fuel injector test light to do this. The issue can be a bad injector or a problem with wiring to any of the injectors on Bank 2, so you have to check/test both.
I hope this gives you some direction to follow. Don't despair - I'm sure it is fixable
This allows me to at least start in the right place and saves me wasting any more money. I'll try the starter fluid test tomorrow and try some fuel injection cleaner in the tank which might unclog a dirty injector?
I have a couple of friends in the trade so I can also use your post to explain to them and see if we can finally get it fixed. Would I be right in saying that the engine is initially running lean and is now over compensating by adding extra fuel hence the fuel trim readings?
And yes bank 2 would be the passenger side on a UK car so that also helps me narrow it down.
Sincerely thank you for all your help, I don't feel as frustrated and flustered now!
Best regards
Paul. 👍😊
#7
11-15-2016, 08:01 PM
Thanks for the kind words Paul. I've been there myself feeling lost with all the computer controls on the modern engines. I was lucky to come by some reading and viewing materials on the web that helped me to understand what is going on and now I just try to help others as well as I'm able.
You are correct - your engine is running lean right now but only on Bank 2.
You are correct - your engine is running lean right now but only on Bank 2.
#8
11-16-2016, 10:08 AM
Hi just to update I couldn't locate any vacuum leaks on bank two and was wearing of spraying starter fluid in case of fire. I've added some fuel injection cleaner which has received fantastic reviews and I'll continue to monitor my bank 2 fuel trims to see if they decrease, so far P0173 has not reappeared. However P0125 remains.
Do you think it's worth me changing the thermostat ? Although it appears my coolant system is working as it should, I'm perplexed as to why P0125 remains if that's the case.
Thanks
Paul
Do you think it's worth me changing the thermostat ? Although it appears my coolant system is working as it should, I'm perplexed as to why P0125 remains if that's the case.
Thanks
Paul
#9
11-16-2016, 10:35 AM
I'm pretty sure your P0125 is related to the high fuel trims. Here is why: When all systems work well, PCM runs in what is called "Closed Loop". This means PCM monitors O2 sensors and adjusts fuel mixture based on those readings to achieve most efficient fuel consumption and lowest emissions. This happens many many times per second. In your case, Bank 2 is running super lean and even after adjusting fuel trim by >30% PCM still can't find the optimum fuel mixture. This causes the engine to cancel the "Closed Loop" and run in "Open Loop". OL is sort of a default condition when things go wrong and when the engine is cold. There is a preset fuel delivery values and O2 readings are ignored. There is a time limit for PCM to reach the "Closed Loop" condition when all is running well. Since your vehicle can't reach CL, PCM says - we have a P0125 condition - too long to reach CL. The temperature reference is irrelevant in this case, since the code can be set under many different conditions.