obdII help

Mission Man
01-03-2020, 11:17 PM
There seems to be so much about particular DTC codes out on the web that it is almost overwhelming, however I have failed to find this answer.

My reader will display a list of 13 specs about the vehicle and I wonder if anyone can help me use this info. to decipher probable causes of code.

Here the list:
Fuel Sys 1 ol
Fuel Sys 2 ol
Calc load 5%
Ect 185 deg F
STFT B1 0%
LTFT B1 2.3%
STFT B2 0%
LTFT B2 6.2%
Map 8.2 in hg
eng. RPM 1121
Veh. Speed 32 mph
Maf 0.82 lb/min
TPS 0.0 %

This particular vehicle is a'98 Isuzu Rodeo with a 3.2 v6 engine and a 4L30e transmission.

How about it? Anyone help educate an old dog??

01-17-2020, 03:52 PM
looks normal. actually good

01-17-2020, 03:53 PM
wait no tps %

Mission Man
01-17-2020, 10:37 PM
now let me give you the rest of the story.
When I posted this, I had discovered that the vehicle's transmission was going into safe mode meaning that it would start out in 3rd gear unless you manually shifted it into low. Also a few codes had been cleared which were high voltage, o2 sensor bank 2 sensor 1 heater, and a few others. After clearing codes the Rodeo did not return to normal shifting....
I have replaced the 02 sensors on the passenger side of the Rodeo but it did not seem to take care of the safe mode shifting, or so I thought.
One thing I have failed to mention in all this is that there has been an ABS and brake light coming on. I noticed the brake fluid was low and topping that off took care of the brake light but not the other. Thinking that was a different problem altogether I have been ignoring that until the morning (rather cool morning) I left for work and the Rodeo shifting beautifully 13 times until the ABS light came on again. Yes that morning no warning lights of any sort were showing on the dash.
When I got to work and checked for codes, even though the check engine light was off, I found that there was an 02 bank 2 sensor 1 code pending.
So, the current status is that I have noticed when the Rodeo is cold, no codes, and or dash lights are on and she shifts like supposed to for about 5 miles, give or take a few, and then the ABS light comes on. But, if I have the blower motor going, the lights and fog lights on, and then turn on the rear window defroster, the ABS light goes out. doesn't help with the fail safe shifting but seems quite odd. Also, I notice that with all this on, at times the battery and brake light will come on but will be dimmer as well as the head lights and a little slower hum in the blower motor until I turn the defroster off. I'm wondering if I have a bad ground somewhere or the alternator is malfunctioning but bumps in the road do not seem to cause a change in the symptoms either way and my battery/charging system tester shows the charging is ok.
I have recorded more of the original listed data as it has been changing from time to time, unfortunately, that info. is in the Rodeo at work and will have to be posted at a later date.
Any thoughts?????

Mission Man
01-17-2020, 10:39 PM
by the way,STFT B1 0%
LTFT B1 2.3%
STFT B2 0%
LTFT B2 6.2%
I think this information is pertaining to the o2 sensors.
am I right?

Mission Man
01-29-2020, 06:04 PM
Ok, I have the rest of the stats on this vehicle.

Fuel Sys 1 ol drive
Fuel Sys 2 ol drive
Calc load 56.4%
Ect 158 deg F
STFT B1 1.5%
LTFT B1 .7%
STFT B2 1.5%
LTFT B2 .7%
Map 8 in hg
eng. RPM 3014
Veh. Speed 52 mph
Maf 9.16 lb/min
TPS 54.5 %

These were the results after changing both the up draft and down draft o2 sensors on the passenger side and going for a test drive. The vehicle was still warming up and shifting properly, so upon leaving the 4way stop I gunned it quite well to see how it would handle. Took off great, shifted nicely and then at somewhere around 50-55 mph the check engine light came back on and the unit went back to safe mode shifting.

The codes set where:
2 times p0155 o2 heater circuit bank 2 sensor 1.
p1153 insufficient switching bank 2 sensor 1

Cleared codes and again took for a drive.
Transmission still in safe mode.

Mission Man
01-29-2020, 07:33 PM
So the next day I got an inspiration to remove the ABS fuse and see how things did. IT SHIFTED GREAT! Thought I had zeroed in on the problem and decided to take Rodeo home and see how things went and before I left the lot, it went into safe mode.
Tried with fuse out, clearing codes (none set), fuse in and it would start to shift right but then, FAIL SAFE MODE, again.
These are the readings once I got home:

Fuel Sys 1 cl
Fuel Sys 2 cl
Calc load 4.7%
Ect 120.2 deg F
STFT B1 -5.4%
LTFT B1 10.1%
STFT B2 2.3%
LTFT B2 14.8%
Map 8.5 in hg
eng. RPM 986
Veh. Speed 0 mph
Maf ??? lb/min
TPS 0.0 %

Some how forgot the MAF reading.
It was on this trip that I discovered how the rear defrost button played into the picture.

Mission Man
01-29-2020, 07:42 PM
So when I returned to work I tested the charging system and found it to be ok. That is at idol.
I'm wondering if the alternator could be flaking out at different RPMs and causing voltage problems.

The final readings so far are:

Fuel Sys 1 cl
Fuel Sys 2 cl
Calc load 6.6%
Ect 195.8 deg F
STFT B1 -2.3%
LTFT B1 12.5%
STFT B2 0.0%
LTFT B2 14.0%
Map ??? in hg
eng. RPM 901
Veh. Speed 6 mph
Maf 1.07 lb/min
TPS 0.0 %

some how missed MAP sensor this time.

The little Rodeo drives great and shifts wonderful when it is cold, I sure wish I could get to the bottom of the fail safe mode in the transmission. The Check Trans light never comes on except at start up when the system checks it's self.

Any input would be great.

Mission Man
02-23-2020, 08:41 PM
well, I guess it's true. You can't teach an old dog any new tricks.

Mission Man
07-28-2020, 11:13 PM
well, I guess that was a bust!

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