Topic: Maintenance Light

[Jeffy]

yeah, the YJ dash is completely analog and i can't see them implementing a mechanical trigger even in the 90s for that, just wouldn't make much sense

but that light is completely stupid, i think they did it for the European market, i recall all cars in late 80s and 90s having this annoying feature so they would force you to go to the dealership. in the Jeep's case what is odd is that as it was back in 91-92 this maintenance light would turn on after the warranty expired (can't recall but i think it was 50 or 75k or 5 years but someone should confirm) so wouldn't be covered during regular inspections 

they did remove it starting 93 as we could see in the FSM, i wonder if there were any complaints about it or something

Well, like I said before I have had an inaccurate speedometer for about 5 years before I calibrated it.  That's a lot of miles, more then a 100 miles difference I'm sure.  Strange that it would coincide with 82,600 miles on the nose and not some more random number. The 1987-1990 used an external timer box.

[neale_rs]

It's surprising they would go to the trouble of designing a timer box just for that.  Was is required by federal law at the time?

[sharpxmen]

it was something in Europe for sure but i have no idea what, i think it's similar to what the OBDII is today with the CEL when cat efficiency falls, so would require that you replace the cat and O2 sensor at that point, could be similar for North America but then they came out with the dyno testing for the emissions and OBD2 after that - my guess anyway, just speculation.

[Jeffy]

I'm gonna say it was done at a time when computers started appearing in cars and were able to relay and store information.  PCV (1961), Air pump (1966), Evap. Canister (1970), EGR (1973) and catalytic converters (1976).  ALDL (1980) was the predecessor to what we know as OBD.  OBD was standardized by SAE in 1988 and in 1991 was required on cars sold in CA.  After OBDI was introduced you didn't need a timer but rather knew when a sensor was bad when it brought up a CEL code.  Really the only thing a MFG. would have to warranty is the cat.  That's covered under a Federally Extended Warranty and is required to last 6-8 years or 60-80K miles depending on the year.  My Jeep was 8/80.

it makes sense for a mfg to add an idiot-proof way to let the driver know that something should be checked and maybe replaced.  A seperate timer would make sense on a car that doesn't have a computer.  (or a computer that's able to relay information.)  Once OBD came into being, the timer was most likely a hold-over for the old system.  The when OBD proved that it wasn't a here today gone tomorrow standard they did away with it.    From what I've read the timer was only available on 1988-1990.

[sharpxmen]

so if yours was 80k warranty then it makes sense to have it at 82,500

[Jeffy]

so if yours was 80k warranty then it makes sense to have it at 82,500

I've had 3 cats in that amount of time though...  The first one was a recall.

[SDWE61988]

Was  CA emeissions thing?  I know I don't have that on my jeep, but it is a 95, (well that part of it anyways)

[Jeffy]

Was  CA emeissions thing?  I know I don't have that on my jeep, but it is a 95, (well that part of it anyways)

No, it was a Jeep thing.