My 97 Z28 has developed an aggravating P1657 (skip shift solenoid) error code that I have been trying to track down for weeks. Like most M6 owners, a skip shift eliminator was one of my first purchases after buying the car.

Eventually, I removed the function (but not the monitoring, I know) with LT1Edit when I supercharged the car and started custom tuning it. The solenoid checks out, and I tried the standard trick of several common resistive values (20, 2.5K and 2.9K) Ohm shunted across the solenoid connector (just like the skip shift eliminator), but no luck. Maybe a problem in the harness somewhere, but voltage at PCM pin B13 looks right.

I'm now in need of a State Inspection, but the inspector at my usual place tells me that the OBD2 test machine (I'm in the Dallas area) will automatically fail the vehicle if it has an MIL (SES on our cars) lit. All other tests scan good on the car. EGR, AIR, O2, Heated O2, Catalyst, etc all show complete. No incompletes or not ready results.

I think the fail for SES may be BS, but i can't find any info on the State's web site to confirm this. Anyone know for sure?

Johnson

 

As far as I know that is true. I live in a non-emissions county so they didnt hook my car up so I was able to just remove the SES bulb from the cluster to get my car to pass. Removing the bulb tripped another SES code, imagine that.

 

From what I have been told SES light illumintated will not cause the car to fail inspection. It depends on the code that is set in the computer. If it is an emissions related code it will fail.

Since skip shift code is not emissions related it should pass.

 

A lit SES light is an automatic fail .. No matter what is causing it. No idea where you'd find the info. other than on an inspection machine. It'll ask you if the light turns on when you put the key to the "on" position... The once started, it asks you if the light turned off.. If the question is answered no.. Then the car is failed automatically.

 

And to think I used to consider you a friend! Thanks for the info. I don't really blame the messenger.

Oh, well...this particular problem has gotten well beyond my pay grade at this point. I guess I will have to take it to...GASP...a dealer.


Johnson

 

And actually the skip shift is somewhat of an emissions item seeing as it is truly for the gas mileage issue and RPMs and all of that other crap.

Register the car in a non-emission county and pay the $12.50.

How does the solenoid check out? Are you applying voltage to it?

 

haha! long time no see!

 

go have them run it in traing mode that is free and if it passes then have them run it

 

any machine test is free.. The inspection station dictates the amount charged to the customer - txdot only sets a maximum allowable price to be charged.

 

training mode is free