Oil Life, Transmission Fluid life, What else?

[Bruce Nunnally]

I of course love the oil life monitor and the transmission fluid life monitor. These to me are excellent examples of onboard prognostic (predictive) indicators. The oil life monitor for example does not simply tick off every 3K miles, but monitors the way that the Cadillac is driven and then estimates the condition of the oil with a high degree of accuracy.

What else would you like to see monitored in a similar way?

I would like to suggest Tire rotations on vehicles which have the same size wheels/tires on all 4. Tires traditionally should be rotated "every other oil change". However, that was when "every other oil change" was about 6K miles total, since oil was changed every 3k miles. Now I noted that the tire place said please rotate the tires every 6K-8K miles. But I would prefer to have a "Tire life monitor" which if nothing else would count down every 6K miles and display %'s along the way, and a warning message at complete.

Wind shield wiper replacement seems a minor but reasonable thing also. I was surprised to hear them recommended to be replaced every season (spring and fall). I traditionally replace mine when they stop clearing the windshield, but that means I wait until it is difficult to see out of the vehicle while driving, which is probably a poor plan. A reminder message every 12 months for windshield wipers would be okay.

What additional items would you like to have onboard prognostic indicators for like the oil life monitor?

[Cadillac Jim]

I would like to see a 30,000 mile reminder on transmission fluid. Other things that come to mind:

• Brake pads; the modules can do this.
• Brake fluid and power steering fluid; ten years?
• Cabin filter.
• Air cleaner element.

Another thing I would like to see is measured fuel octane. With IAT, MAP, barometric pressure, ECT, and the knock sensor, the module has all it needs for a pretty good estimate of fuel octane. Can we see it?

One thing I would like to see is better integration of the GPS with the rest of the car. GPS could be standard and provide data to the nav system if installed, but it could, with magnetic declination and time zone maps, also provide magnetic correction to the compass in the mirror, accurate time to the radio display and other things that are manually set in the existing system. The additional possibilities are interesting, such as speedometer/odometer cross-check, where-has-this-car-been memory for a week or two, altitude compensation to supplement MAP and barometric inputs to help keep the FI accurate while climbing long grades and such, and theft prevention.

OnStar data transmission could include a running data check and not require that the system go into the modem mode and ring back by using existing digital data channels in the cell phone system.

The 42 VDC system seems to be not coming because it raises more problems than it solves. I worked out a three-phase-with-neutral system in 2000 that would solve the arcing and safety problems, as well as the ground return, copper weight, and other problems.

[Bruce Nunnally]

Those are all good ideas. I especially like the brake pad monitor idea.

The current GPS iintegration just makes me sad. I think that every Cadillac with onstar has a GPS system built in, but OnStar is the only interface. I may be confused in that only cars with nav systems have GPS, but my impression is OnStar needs GPS to tell where the car is for some of the services they provide. Just a simple DIC interface that brought out the GPS info would be interesting, but I guess that's the point of the Nav system is that it adds the displays and interfaces and maps that make GPS info useful.

I am surprised about the 42VDC. I thought that it was the key to electric A/C and other heavy power needs.

[JimD]

Cadillac had a brake pad monitoring system that they stopped installing at some point. Don't know why they stopped using it.

The OnStar GPS has been hacked if anyone is inclined to break out the signal. This page is old information;

http://www.i-hacked.com/content/view/15/45/

[steve6]

my transmission life indicator has never moved in either caddy i have owned, did that ever get fixed?

[JimD]

my transmission life indicator has never moved in either caddy i have owned, did that ever get fixed?

There is nothing to fix.

If you are not towing a trailer, and/or not doing something that will put serious heat into the transmission fluid, the count down can take forever.

[Cadillac Jim]

The GPS standard includes an RS-232 compatible interface, and the GPS chip that is used in the OnStar installation will have that electrical signal available. This signal is called the UART interface pins on the chip, and hacking into it is as simple as identifying the pins on the GPS chip that have this signal and connecting them to a UART chip that drives an RS-232 interface; then you can watch the data scroll or whatever on a laptop and do whatever you want with it.

I do understand that the GPS is only there with the OnStar or Nav systems, and it may well be that they use separate GPS chips that are integrated into OnStar and the Nav system. Integrating either GPS with the rest of the car is as simple as making its data available on one of the Class 2 CAN bus lines, and using it where it is available. This can be as simple to do as using a $1.75 Microchip PIC embedded processor to drive the CAN bus from the RS-232 UART data, or talk to another chip that manages the CAN bus locally. But, it would make more sense to me to make the GPS just part of the same module that controls the radio or CHMSL or whatevero, and make its signal available to all modules in all Cadillacs (and other GM cars) for use in the dash and radio clocks, the compass, the PCM, and whatever else might make use of it. For example, the calendar date might be of use in the OLM and other existing functions that now do without it. The already-available GPS capability is then ready to reduce the costs of OnStar and Nav systems.

As far as the 42 V switchover is concerned, it is a good way to cut down on copper wire weight in cars. Lights, motors, and most electronics can be more efficient and robust with a 42 V system, but there are some show-stopping problems that must be solved:

• Safety. Voltages above 22 V can be lethal. There have been electrocution deaths reported from 24 Volt farm lighting systems.
• Arcing. Arching is a problem with any high-powered lead-acid battery system, even 6 Volt, but a high-current arc from a 42 V system can be truly wondrous to behold.

Both problems can be addressed with computer monitoring and relay cutoffs, but relays add a complexity, cost and reliability dimension that cuts right to the heart of the reasons for going to 42 V systems in the first place.

My proposal was to use a standard cable throughout the car consisting of four-wire, three-phase power with neutral, and multiply redundant fiber optic lines for the system data buses. It's hard to get DC-and-relay thinkers to even look at something like this because it uses 21st Century technology to solve problems now solved by mostly 50-year-old technology and thus requires adoption of a disruptive technology. Besides, everybody internationally has already agreed to go to a 42 VDC system...

Think about a 42-volt 400 Hz three phase system with neutral. Here's the principles, and the solutions to the most obvious questions:

• The central power sources for the system is a three-phase inverter that is part of a quartet of DC-based components. The alternator, battery and starter can be 12 V, 24 V, 42 V, or whatever; the inverter can be designed to run off of just about any DC voltage.
• Switching, and even dimming, can be done using triacs.
• Safety and arcing can be accomplished by monitoring neutral currents, like as is now done in existing GFI protection in household and other circuitry. With a 400 Hz signal, a short, arc, or electrical shock can be terminated in a time that cannot exceed 1.25 milliseconds, the time of a half-cycle at 400 Hz.
• Power and switching to DC loads like lighting, power, and DC motors can be done with triacs and a 6-phase rectifier. No filtering or additional components are needed except possibly for some electronics such as sound systems.
• With a three-phase system with balanced loads, ground returns aren't necessary. Unbalanced loads offer no advantages so you just don't use them in the system.
• 400 Hz was adopted as the standard in aircraft systems because this frequency represents a near-optimum for size, weight and efficiency of motors. Size, weight and efficiency are more and more important in automobiles, too, these days.
• The resulting overall production and life cycle cost of this system is more than competitive with that of the 42 VDC concept.

[Bruce Nunnally]

In the Escalade Hybrid the electric power steering runs on 42 volts

Energy Storage System (ESS)

Providing power to the hybrid’s electrically variable transmission’s (EVT) two electric motors is a 300-volt nickel-metal hydride Energy Storage System (ESS). This battery pack is located under the second-row seat, where it takes up virtually no additional space and does not interfere with second- or third-row ingress/egress.

The primary function of the ESS [bruce:Battery] is to provide power (300 volts) to the EVT and to store captured energy produced during regenerative braking. In addition to supplying power to the EVT, the ESS also provides power to the air conditioning compressor and the Accessory Power Module (APM), which converts the high-voltage supply to 42 volts for the electric power steering system, and 12 volts for the vehicle battery and other 12-volt electrical accessories.

Battery pack durability and reliability are maintained via optimized charge and discharge cycles, as well as a dedicated cooling system that draws air from the passenger compartment. As part of the vehicle’s emission control system, the ESS is warranted for eight years/100,000 miles.

[navion]

Has anyone mentioned an antifreeze monitor?

How about a battery condition monitor that periodically performs a battery capacity test?

Britt

[Bruce Nunnally]

A coolant life indicator could be particularly useful. My understanding is that although they are not directly related, the pH of the coolant is also an indirect measure of the expected life left in the coolant as well since the amount of additives left in the coolant relate to the ph or similar.

The first thing my local repair shop did when we brought the battery from the Mountaineer to be replaced was attach it to a hand-held battery tester. The tester very quickly determined if the battery was merely discharged or needed replacement. I agree that some type of battery test circuitry which would warn that the battery is failing would be much better than sitting with the car unable to start in the morning. Good pick.

[JohnnyG]

Well, there you have it! The top four ( make that 5, I just added one) next monitor systems (in my book), and some can be mere timers are:

A REAL battery life indicator

An OIL FILTER change indicator (This is the one I added, with 12,000 mile oil changes, this one could work off of differential pressure)

A Coolant service reminder

An air filter change reminder ( this one can be more elaborate, working on differential pressure)

A cabin air filter change reminder

[Poobah]

Head gasket life monitor?

[Ranger]

My '02 SLS had the brake warning indicator. My '03 DHS doesn't. It was so simple and cheap, I can't understand why they did away with it. I think it was a poor decision. Likewise, the old lamp monitors. They were so "Cadillac".

[Texas Jim]

Likewise, the old lamp monitors. They were so "Cadillac".

Loved them....

The lamp monitors were so neat.

White for lowbeam

Blue for high beam

Amber for park lights/ turn signals

And RED up over the back window for tail lights and brake lights and turn signals.

[KHE]

Lamp monitors

Trumpet horns

Opra lights

Power trunk lid pulldown

Stand-up hood ornament

Put the merilatts (sp) and the seven jewel "crown" back on the emblem

[TDK]

Dear All,

Engine Belt alarm:

It seems to me that engine belts still break unexpectedly. Perhaps a thin monitor wire/chip set could be embedded within the belt. As the belt rotates, the wire creates a null signal pulse past an electronic monitor, because it is unbroken. As the belt wears and cracks, the wire evenutally breaks and generates an pulse alarm - before the belt itself breaks.

Trunk floor water alarm:

If a trunk seal fails or the beer cooler leaks, you need to know - before the skunky, moldy odor alerts you. This seems relatively simply and would stop corrosion issues.

Just a couple of easy ones for GM to ponder.

[Texas Jim]

Engine Belt alarm:

It seems to me that engine belts still break unexpectedly. Perhaps a thin monitor wire/chip set could be embedded within the belt. As the belt rotates, the wire creates a null signal pulse past an electronic monitor, because it is unbroken. As the belt wears and cracks, the wire evenutally breaks and generates an pulse alarm - before the belt itself breaks.

I LIKE THAT IDEA.

On my DTS you can barely SEE the darn belt.

There is hardly any way to even check it to see what it looks like to see if it needs replacing.

[JohnnyG]

Engine Belt alarm:

It seems to me that engine belts still break unexpectedly. Perhaps a thin monitor wire/chip set could be embedded within the belt. As the belt rotates, the wire creates a null signal pulse past an electronic monitor, because it is unbroken. As the belt wears and cracks, the wire evenutally breaks and generates an pulse alarm - before the belt itself breaks.

Yeah! I like that one too.You'd have some time to get the belt(s) changed of course, so it wouldn't ruin your trip, but that's a great idea!