Trying to force check engine light

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Trying to force check engine light

February 27, 2020, 04:42:23 PM

Trying to force a check engine light on my 01 Grand Marquis by leaving the gas cap off. I drove 15 miles stopping an restarting 3 times, no light. I want to force it to store "freeze data" so I can see what the PCM thinks the engine temp is.
Anybody know what a drive cycle is and how many do I need?

Re: Trying to force check engine light

Reply #1 – February 27, 2020, 09:22:37 PM

I don't have a direct answer to your question.

Being as it's an OBD2 car, can't you monitor the data with a scanner? I was using an ELM327 and the Torque app before to monitor various sensors on a few cars.

Re: Trying to force check engine light

Reply #2 – August 12, 2020, 11:01:57 PM

i went one further than tbird232. i picked up an ob2 adapter that plugs into my laptop through a USB port, and downloaded the free version of forscan(fords diagnostic software) as well as obdwiz. i can save any scan i do on my 05 grand marquis for later. i havent yet explored the dashboard yet, nor other functions, but it is quite informative. this is the adapter i purchased from amazon;

https://www.amazon.com/gp/product/B081VQVD3F/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

Re: Trying to force check engine light

Reply #3 – August 13, 2020, 07:47:24 AM

Does your check engine light work? Just wondering if the code is there but the light is not illuminating.

Re: Trying to force check engine light

Reply #4 – August 17, 2020, 04:38:55 PM

My situation was, my buttstuffog temp gauge was slow to warm up and sometimes cooled down when up to speed.
My EVTM shows the same sensor feeds both the gauge and the PCM.
When the PCM sets a check engine light it records the freeze frame data.
I can readout the freeze frame data with my OBD code reader and coolant temp is part of that data.
I wanted to force the check engine light so I could see if the PCM agreed with the gauge that the coolant temp was low.

I finally gave up trying to be clever and just replaced the thermostat and everything is good.