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lanxer57 11-23-2021 02:40 AM

Re: specifics on compression testing, P0301
Passing an emissions test is the most important thing to fix, but I did notice that the brakes desperately need to be bled (the pedal almost sunk to the floor, and the brakes gave little response), and the wheels were rubbing something when turned. I am also reluctant to drive it outside of small residential streets until I can get the automatic transmission to stop leaking. (maybe I should replace the side cover gasket again?)
At speeds not exceeding 20 MPH, and driving VERY conservatively, the engine seemed to work fine. It did shift a little hard, but I thought it had to "relearn" how after getting the valve body replaced.
I suspected that "did not complete SC" might refer to some kind of test that needs to be done after removing the PCM-B fuse, but these tests are said to involve going 55 MPH, and than coasting to 20 MPH, something that I believe is illegal (at least where I live) because it would be considered "impeding traffic". Even if that kind of behavior is legal, driving at all in a vehicle that has not passed an emissions test is not legal either.

fdryer 11-23-2021 02:11 PM

Re: specifics on compression testing, P0301
Are you aware of removing the pcm fuse, battery disconnect or push button reset on an obd reader or scantool resets the check engine light and erases error codes? Any errors that aren't corrected reappear on the next startup. Whether you know it or not, once the pcm is reset with the cel off, the car won't pass state emissions inspection because the pcm was reset to factory defaults with readers/scantools displaying the vehicle in Not Ready status. Instant failure at emissions inspection. Resetting the pcm requires the vehicle driven the minimum 'drive cycle' of 50 miles to have the pcm learn all new emissions parameters involving measuring coolant temps from cold start to fully warmed up, egr operation, both O2 sensors, map, throttle position and evap system. You can search for GMs drive cycle but it basically means driving in local and highway conditions with stops along the way as emission monitors are learned and compared with programmed values. Inspection stations are well aware by reading obd status the same way diyers can with commercial or personal readers and scantools.

If each measured parameter falls within range then the obd system sets a ready status. If all parameters are within range the system will have a ready status, meaning the car already passed its self tests relative to emissions testing and will pass state/federal emissions inspection. A reader or scantool with this function should display all the monitors and whether or not each one went from not ready to ready status. Your state DMV will have info on how many monitors can fail yet pass inspection. Some states allow one or two monitors to fail but still pass inspection. Other states won't allow a vehicle on the road if one monitor fails. Readers or scantools will display which monitors haven't reached ready status. A good reader will tell whether or not a vehicle is ready for emissions inspection long before visiting state inspection stations.

lanxer57 11-23-2021 07:25 PM

Re: specifics on compression testing, P0301
Would a reset trigger a service wrench light? Any ideas on how to complete a drive cycle in an unregistered, uninsured vehicle without drawing attention from the police?:arr:

fdryer 11-23-2021 08:30 PM

Re: specifics on compression testing, P0301
My limited knowledge of OBDII doesn't have any info stating resetting the engine computer triggers a wrench error/light. You can wander thru everyone posting threads about resetting their PCMs with battery disconnect, pcm fuse pulling or using a reader to reset the cel. None have ever seen their wrench light turn on for manual resets. Even my L300 doesn't turn on its wrench light when I manually reset errors. Your wrench light indicates something unrelated to emissions triggered the light. Something as minor as a burned out instrument panel or turn signal lamp. Generic readers won't decode wrench errors. Manufacturer specific readers or scantools can. Emissions errors take priority over minor issues lie a burned out tail light so the majority of readers decode only emissions related error codes, P type. C codes are for chassis, U for network and B for body control module error codes.

Unfortunately, once anyone manually resets their cel just before state emissions inspection will be seen by inspectors as a Not Ready status as soon as they plug in their state computer to a vehicle. They don't see anymore info than we do with personal readers. Most members here with this issue are given a friendly warning that their system was reset and will need to be driven a few days or so and return for another scan when daily driving meets all the parameters for the GM drive cycle. Many perform their drive by simply using their vehicle in normal everyday driving and return to find out their car passes. Others find out one or several monitors haven't completed and cannot pass inspection until repairs and follow-up drive is recognised by the on board diagnostic system as a correct repair to change the remaining monitors to ready. Some complete a drive cycle the same day, others take a few days while some take longer. All due to variable daily driving routines. The ones that can't complete a drive cycle are shown which monitors are still pending (not ready status). Many aren't aware of just leaving the error code alone and making honest attempts at repairs then let the obd system automatically detect corrected errors to reset error light automatically. Some errors are reset automatically on the next ignition on/drive while others reset the light but require up to three drive cycles (ignition on, startup, drive, ignition off) before a pending error code is erased and a ready status is seen on a reader/scantool. It's simply easier to use a good reader or scantool to determine when repairs are made, let the system reset any errors, and check for ready status before inspection takes place.

The obd system automatically runs on every engine run, monitors everything and if nothing fails, leaves the cel off. If at any time a fault occurs, monitoring halts at the error and resumes only if a correct repair occurs and is detected on the next ignition on/drive. The system is left alone with a correct repair as all monitors aren't reset and the corrected error is detected on the next startup to erase the error code and turn off the light. This is the best way to an inspection coming up if an error code pops up, not manually resetting errors. If the error remains, the halted obd system simply waits with all other monitors in ready status for the correct repair to occur and detected to switch the one not ready status to ready. Leaving the obd system alone and fixing the error correctly lets the system detect the corrected error to resume monitoring, clearing the error to return a vehicle to legislated emissions requirements immediately. Manually resetting errors erases all parameters and requires a drive cycle to relearn them.

You'll have to call DMV for directions on how to get your obd system to run to get all monitors to ready status. Your alternative might be driving around, carefully avoiding police at night to let the obd system run its course. Having a reader or scantool plugged in can help determine which monitors are ready or not to tell you whether the car is ready for inspection or not. You'll need a reader that will display emissions monitors in ready or not ready status.

lanxer57 11-23-2021 11:27 PM

Re: specifics on compression testing, P0301
The instrament panel? The left turn signal indicator is burned out, would that cause it? The horn is also not working. Does the PCM care about the horn? I never use it.

1996SL11.9L 11-24-2021 10:08 AM

Re: specifics on compression testing, P0301
Itís possible that the wrench is for your turn signal lamp.

My Innova hand held scanner and MacMentor I think are the only devices able to read the non OBD GM specific trouble codes.

fetchitfido 11-24-2021 10:20 AM

Re: specifics on compression testing, P0301
The "[COLOR="Orange"]Service(Wrench)[/COLOR]" light is for non Emissions related things, like burned out indicator bulbs.

Reading what it has for a code requires at least a Tech II level tool, if not a Tech II specifically.

Has no impact on emissions, but it's up to the inspector as to it passing inspection or not.

fdryer 11-24-2021 01:59 PM

Re: specifics on compression testing, P0301
If you don't have a better ($$$) reader or scantool to decode wrench light error codes, the cheapest alternative is repairing what's broke. If you can replace a burned out turn signal light bulb, try it. You have nothing to lose but time and a few dollars. The horn failure may be either the steering wheel touch switch or horn itself. The horn and switch can be tested by disconnecting the horn and connecting a 12v bulb or measure for 12v when the horn switch is pressed.

Electronics uses circuits to measure for open or grounded (short) connections as feedback for programmed error codes. These circuits were designed when computerized systems grew from demand for better monitoring of vehicle electronics and electrical systems. The easiest one to understand is the battery light - on with ignition before starting, off after starting and on when the engine's running to indicate something wrong with the electrical system. The battery light replaced older ammeter and voltage meter to eliminate gauges not necessary for the average driver unfamiliar with amperage or voltage gauges. The 'idiot' light is all that's needed when alternators replaced generators with external voltage regulators using relays. Solid state electronic voltage regulators built into alternators allowed a simple battery light to inform the driver of one of three states of electrical system operation.

lanxer57 11-30-2021 12:22 AM

Re: specifics on compression testing, P0301
All the bulbs on the instrument panel are now working.
I also tried to fix a transmission leak by sealing the valve body cover gasket with rtv silicone. I drove it for a few minutes and it did not blow up at speeds up to 40mph while almost flooring it. It did shift a little bit hard, but was not slipping. The service wrench light did not return until I drove uphill at about 25mph for at least 10 seconds, and the wrench light came back... P0733, incorrect 3rd gear ratio. I also looked underneath it, and trans fluid is still dripping, but it is no longer pooled up around the edges of the valve body cover (where the bolts are). I recently swapped the valve body with one from my 2001 SOCH, could that be causing this new code? The turn signal switch also seems to only work intermittently.

fetchitfido 11-30-2021 01:14 PM

Re: specifics on compression testing, P0301
The Service (wrench) light does not come on for engine/transmission codes. Only the Service Engine Soon light does engine/transmission codes. They're in a similar spot, but different lights. Wrench light is #5, SES is #4 in the below picture.


billr 11-30-2021 01:46 PM

Re: specifics on compression testing, P0301
The VB is same for both SOHC and DOHC.

fdryer 11-30-2021 02:13 PM

Re: specifics on compression testing, P0301
P0733 is a SES error code, not wrench error code. As mentioned previously, unless you have a better code reader programmed to read every GM code (P, U, B, C types) like GMs Tech-2 or an aftermarket scantool like VCX NANO, you're decoding generic P type codes. In this case, the error points to possibly something as simple as low xmission fluid when 3rd gear isn't detected at the right time in upshifts. The loss of xmission fluid should be the hint of this error code. Topping off xmission fluid should help reset the service engine soon/check engine light on its own without manual reset.

lanxer57 11-30-2021 07:01 PM

Re: specifics on compression testing, P0301
After I tested it last night, I also checked the transmission fluid dipstick, and it looked like the level was directly in the center of the cross-hash area, despite a very slow drip. It probably was service engine soon, but I did not look very closely, and never noticed how similar they look at a glance. Both yellow, contain the word "service", and are right next to each other. I was more concerned about the difference between years, because they are both SOCH.

lanxer57 11-30-2021 07:54 PM

Re: specifics on compression testing, P0301
I just took it out again, and it still says 3rd gear ratio is incorrect, but also says it is running rich (P0172), and it is the service engine soon light

TomM96 11-30-2021 08:33 PM

Re: specifics on compression testing, P0301
When troubleshooting, it is advantageous to proceed carefully, generally
addressing One issue at a time; it can be helpful to write down a record
of symptoms observed, and tests, or corrective interventions attempted.

TAAT ATF level is tested with vehicle at full operating temperature,
at idle, in neutral or park on flat surface; check both sides of the dipstick.

billr 11-30-2021 09:03 PM

Re: specifics on compression testing, P0301
After about '93 the VBs are all the same.

lanxer57 12-03-2021 01:02 AM

Re: specifics on compression testing, P0301
I forgot to mention that I sometimes have to shift it in and out of park before it will crank, because I have become so used to it that I barely notice. I suspect that this problem is likely caused by a problem with the neutral safety switch. Could this also be contributing to an incorrect 3rd gear ratio?

1996SL11.9L 12-03-2021 10:21 AM

Re: specifics on compression testing, P0301
That incorrect ratio code means that third gear is slipping or non existent.

When it commands 3rd gear it expects to see a certain correlation between input rpm and output rpm/mph.

lanxer57 12-03-2021 03:12 PM

Re: specifics on compression testing, P0301
I did not feel like it was slipping or non-existant (as if in neutral?) at any time that I drove it, just shifted a little bit hard a few when accelerating. It was not accelerating or shifting when the SES light came back.

lanxer57 12-04-2021 08:37 PM

Re: specifics on compression testing, P0301
This was the live data taken idling in park at about 750 RPM, IAT was about 60F, and coolant was 207F
STFT was between -33 and -36
LTFT was -17.2 (Are these good values?)
MAP sensor was reading 9 inches of mercury, a vacume guage had read 34 inches of mercury previously in the same hole (is the sensor bad?)
O2 sensor 1 reading fluctuates between about 0.35V, and 0.75V
O2 sensor 2 reading fluctuates between about 0.28V, and 0.68V (are the sensors bad? What do good readings look like?)
spark ADV was between 16 and 20 (Does this matter?)
TPS was 0%, I was not touching the throttle
O2 sensor readings are listed again for some reason, with the same values, except they are positive
STFT was listed again as sensor 2, 99.2% (Does that represent the amount of air, or fuel?)
That is all the live data my obd2 reader can read that is relevent (unless you want to know that it has fuel, or something)
The fuel pressure test result was earlier in the thread.

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