Hi guys. Reprogramming of the engine computer can be done for numerous reasons. When a recall is involved, those relate to safety concerns, emissions issues, or sometimes customer satisfaction complaints.
There is a software package installed at the factory that provides a base line or starting point the computer uses for fuel metering calculations and spark timing to get the best fuel mileage and lowest emissions. There are "lookup tables" where, based on things like coolant temperature, throttle position, throttle direction of change, throttle rate of change, load on the engine, engine speed, intake air temperature, and dozens of other things, the computer finds the exact specified amount of fuel needed and when to fire the spark plugs. Sometimes the engineers discover that under just the right combination of sensor data and operating conditions, emissions might go above the legal limit for as little as a few seconds. They will update the software to address that, then that updated software will need to be installed in the car's computer.
Things change too when some wear has taken place in the engine. There may be something advantageous in terms of better fuel mileage, smoother shifting, or increased performance that could not be accommodated before the engine's break-in period. Based on the vehicle's mileage, the manufacturer may request the dealer install the pre-planned software update. One car model in particular that I am aware of will develop seriously-reduced engine power at 20,000 miles so the owner takes it to the dealer under warranty. The revised software is installed at that time.
The fact the engine computer was reprogrammed is a good thing. That means whatever the concern was, it was addressed, rather than leaving it for the next person to take care of.
The codes M_H_RITZEL was referring to are diagnostic fault codes in the engine computer. Those are set when the computer detects a problem. There is about 2,000 things the computer can detect. Roughly half of them refer to things that could adversely affect emissions. Those are the codes that turn on the check engine light. There can be some of those other codes in memory that do not turn on the check engine light. Those should be erased by the mechanic after completing any repairs so they do not confuse the next person who checks them. Most of those fault codes self-erase anyway after a specified number of engine starts, as long as that problem is not detected again.
Be aware too, all this wondrous story applies to the engine computer. That would be the power train control module, (PCM), you listed. I do not know what the "OCS" is, but there are a lot of other computers on your vehicle that have software installed specific to that application. A common one to ask to have reprogrammed is the body computer. It can be changed to chirp the horn when you lock the doors to let everyone know you have an anti-theft system. That function can be turned on or off. Same with power door locks that lock automatically for people who do not know how to push a button. We cannot even install factory options anymore, like cruise control, fog lights, or cargo box lights without reprogramming a computer that runs them to know they are there. The insane engineers have gone way beyond common sense by adding computers to do all the stuff they were never needed for before. To reduce the need to develop a different computer for every combination of options, they use one of just a few for that application, then modify the software to suit the specific vehicle. That means you usually can no longer run to a salvage yard to get a good used computer when needed. Some used computers can be reprogrammed to work on a different vehicle, but only by the dealers, and they do not do that for free. This is one of the biggest reasons I let my fairly new truck sit and drive older stuff from the 1990's.
Thursday, March 15th, 2018 AT 4:37 PM
