How does one pull codes on a 96 T-100 3.4 without a reader? I know on my 93 F-150 it was just a matter of grounding a certain wire and watching the check engine light flash and matching it with a code...

 

Your 96 is OBD II
Your 93 is not. You're talking about two different diagnostic systems.

 

Toyota decided that the dealers needed to make more money. So, to encourage the owner to take the car to the dealership for service, they elimated the ability to read the codes via a paper clip jumper.

I recommend investing in a scan tool from http://obddiagnostics.com/

Interestingly enough, my OBDII Honda has a grounding jumper.

 

Yeah it is kinda strange, my Civc does have the jumper ability too.
Doesn't matter now because I use the Auterra OBD II scan tool anyway.

 

Actually... The OBD II system is non-manufacturer specifc. ALL vehicles manufactured from 1996 on have the system.

There's a LOT more than just code information available from an OBD II system than the paper-clip days. It varies from car-to-car, but on our engines, you can see coolant temp, rpm, fuel trims, timing adjustments, etc.


Other folks have mentioned the two readers that I would (Auterra and OBDDiagnostics) or if this is an infrequent event and you can't justify the cost of a reader, then head to your local Schucks, AutoZone, etc. store and they'll read the code for free.

They usually won't clear it though... There are federal EPA issues surrounding that. If you need to clear it, look into the fuse box under the hood for a fuse marked "EFI". Pull it, wait a few seconds and put it back in. The code will be cleared and the dash light will be off.

 

The OBDII specification from DOT/EPA isn't manufacturer specific, but each manufacturer's system is. It left up to the manufacturer to build the OBDII compliant controller for their cars. You won't get a Ford OBDII ECU to plug into a Toyota engine, but they all output a mininum standardized set of data through a standardized port. P0xxx codes are standardized, P1xxx codes are manufacturer/model specific.

Yes, all vehicles from 96 on must meet the specification, and several met the specification earlier. And while ODBII allows monitoring of various engine data through the port, a huge amount of information is gained simply by reading the code and looking up what could trigger that code. That's why its nice to have a paper clip jumper to output the codes via the CEL light, compared to buying a $100 scan tool.

Beginning in 94, those scan tools were $400 to non-existant outside of a dealership. So, for several years after Toyota removed the ability to pull a code via paper clip, the only place capable of pulling a code was at the dealership, who charges $80 for 30 seconds of work.

Does this not reek of dealer protectionism?

There is nothing in the EPA OBDII spec restricting the clearing of codes. The FSM from the manufacturer recommends reading, then clearing the codes and testing to see if the code reappears, simply to debug glitches.

The CEL turns on when it has two successive trips with a problem. It will shut off by itself when it sees three successive trips with no problems. A 'trip' can be a simple or a complex road test, everything from a cold start, low speed cruising, high speed cruising, with various acceleration and deceleration times, depending on the code involved.

 

...or heading to the local autoparts store. This is 2005, and it's _become_ commonplace for stores to do the read for free.

You can also spend $40-50 on just a reader...


I could see your point in 1996. Trying to make this case now though, in 2005, is a bit hard.


I didn't say it was in the spec... I said there were "EPA issues".

The reason that most places won't clear the code for you is that people will hit up an AutoZone with the CEL tripped, have them clear the code, and then head off for an emissions test. Here in WA, you get an automatic failure if the CEL is on. You could have tripped for a tranny solenoid, it wouldn't matter, it's a fail.


Yeup. Which is how people had gotten around the emissions testing issues in the past. AutoZone clears the code, they keep the engine running, drive around the corner to the testing palace, pass since there're no stored codes, and then drive off "good" for another 3 years.