 Well.... the challenges continue. Before we get into all the latest trials and tribulations just to get the "Check Engine" light working, I thought it would be good to review that the tachometer is now working and how! Turns out both Porsche and the GM LS3 use 58 tooth reluctor wheels! We just needed to find and scope the 5V square wave from the GM reluctor wheel and then route it to the Porsche's DME harness so it could pass the pulse count onto the microprocessor contained on the instrument cluster's circuit card. Sadly that was easy compared to how the check engine light and other idiot lights operate.... SO HERE GOES!! (more photos at the end of the text below) Idiot light operational methods in Porsche 987 and similar models: The DME (engine computer) along with running the engine also monitors various sensors for proper compliance and also for protection.... whenever a fault is found, the DME does its thing to ascertain if an idiot light or message needs to be brought to the driver's attention. Now comes the tricky part - instead of just lighting up a idiot light like in previous technologies - this guy sends out a message on the CANBUS (car tallk for local area network) setting a flag addressed to the microprocessor that is on the instrument cluster logic card to receive for handling. The message is interpreted to ascertain what light it should turn on and there you have it... Oh boy! This method saves the running of multiple unique wires in the harness for every individual idiot light you have. Instead there is just one local area network (CANBUS) that a message can be sent on and all that wiring disappears as its all contained within a logic card on the instrument cluster that is under its own microprocessor control. NOW THAT WE KNOW THIS... how do we get the the GM computer to turn the "check engine" light on and off? In order to pass car inspection, it is a requirement that the check engine light come on initially with the ignition switch and then shut off shortly afterwards with no state conditions recorded. The mind reels at the thought of getting a GM computer logged onto the Porsche CANBUS and speaking anything other than gibberish... You'll see our solution in the photo below  Yep, that's an LED we are manually inserting/installed into the Porsche instrument cluster that the GM computer to turn on and off under its own control - and hopefully pass inspection!!! P.S. would not believe what it took to get the instrument cluster dismantled, much less take it in and out of the the dash   Now it's off to Amelia Island for Concours - so no work on FrankenBoxster for another week or two.
Then the Pinehurst Concours will be here before you know it! That's it for this installment... thanks for reading and viewing.
6 Comments
1/16/2019 07:39:58 am
Thanks for sharing such a useful article. Check engine light is an important part of the vehicle which apparently indicates that the vehicle has some sort of mechanical issues which needs to be fixed. Ignoring the appearance of such warning light could cost a lot. So, such warning signs shouldn't be ignored and the vehicle should be diagnosed by experienced professionals to spot and fix abnormal components of the vehicle. Abnormality in the check engine light could be very dangerous. So, one should inspect the condition of different components including the check engine light of the vehicle on a routine basis.
Ivy Morrison
2/13/2019 07:47:19 am
Mechanical issues, in the oxygen sensor, exhaust system, spark plugs, a mass air flow sensor or gas cap issues are responsible for the appearance of check engine light. Mechanical issues in the above-mentioned components may not have an immediate effect on the performance of the vehicle. But such kinds of issues could jeopardize the vehicle. So, the appearance of abnormal signs shouldn't be ignored and the reason behind the appearance of such sign needs to be identified and fixed in time to keep the vehicle in working order. To fix such kinds of problems, visit 2/16/2019 01:15:45 am
When a car's check engine light illuminates a dashboard, it is usually accompanied by a sinking feeling in the pit of our stomach. This light could mean a major issue like bad catalytic converter or a minor problem like loose gas cap. The appearance of check engine light shouldn't be ignored. The mechanical issues like faulty oxygen sensor, mass airflow sensor, loose gas cap and bad catalytic converter etc. indicated by the illumination of check engine light should be fixed by certified technicians to keep the vehicle in good working order.
Jenny Parker
3/5/2019 04:49:08 am
The appearance of check engine light indicates that the engine has some sort of mechanical issues which needs to be repaired. However, an abnormal or damaged check engine light couldn't identify those issues in time which could bring the vehicle to a halt in the middle of nowhere. So, any sign which indicates that the check engine light doesn't work properly shouldn't be ignored and the reason behind the appearance of such sign should be identified and fixed in time to keep the vehicle in working order. To fix such mechanical issues in the car, visit https://www.grouponemotorwerks.com/german-auto-car-care/ 1/27/2022 02:33:23 am
Ignoring the appearance of such a warning light may cost you a lot of money. As a result, such warning signs should not be ignored, and the vehicle should be diagnosed by experienced professionals to detect and repair any abnormal components. Visit us today to resolve such issues! 11/27/2022 02:28:05 am
In order to pass a car inspection, your vehicle must meet certain standards. For example, your car must have working brakes, turn signals, and headlights. Additionally, your car's exhaust system must meet certain emissions standards. If your car does not meet these standards, it will not pass inspection. Leave a Reply. |
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January 2019
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