OBD I style LED Flash code Reader.

[Ben850]

I made this a couple weeks ago to read the ECC codes from the OBD II port on my '96 Turbo Wagon.
It is documented in my ongoing thread (at this point) to determine my intermittent ECC failure, but I thought it could be mentioned in the tool section.

I was going to do a simple momentary switch, LED and three lead wires. Not needing it until the next day I was bored and decided to repurpose a garbage item.

Here is the Schematic.

LED_code_reader.gif (16.06 KiB) Viewed 20385 times

The mother of invention is sometimes boredom.

The pictures are self explanatory.
Explanations on how to use this to read and clear trouble codes OBD I style through the OBD II port are in a number of threads. I will add links as I find them.
Have Fun.

[matthew1]

Whoa, Ben, this is amazing. I like how you used the body of a deodorant product. Really cool!

[matthew1]

Entered into the Volvo Repair Database.

[Huskyhunter]

Did you ever find a thread on how to read the codes?

[Ben850]

Did you ever find a thread on how to read the codes?

They are read in the same manner as the OBD I under the hood in the '93 to '95 850 series.
It also allows clearing of the codes and resetting service engine light.

There are threads here that explain this, as well as the code explanations.

Search for threads, I will add them to this one as I find them.

https://www.matthewsvolvosite.com/read-codes-volvo-850

This is the info on the codes and the jumper ports while using the OBD I box under the hood.

Through the OBDII port, the pin diagram at the top of this thread actually shows the pin configuration to get information from the ECU Monotronic system.
The service engine light can be reset from there after reading and clearing all codes.
Move the lead from pin #3 to pin #6 to read and clear codes from the ECC. If any codes come back, the issues setting them have not been fixed.
If you have a good ECC unit, and finally get the 1-1-1 code back, you have successfully taken care of the issues and there will be no more flashing lights at startup.

Pin #12 reads ABS codes.
Pin #13 reads cruise control codes.

[Huskyhunter]

Thank you so much! I will mess around with it this weekend.

[Ben850]

I must say, I am glad to have put this into such an accessible unit. It is greasy and durable. Not even damaged in a heavy tool bag while being well utilized.
Double duty coming this spring.

[scot850]

What a marvelous piece of kit! When does it go into production? Is production limited by deodorant use?

Sometimes you guys on this website aren't just great, but amazing!

Neil.

[pappatho]

Does anyone know which pins are used to read mileage?

[esl_97_850_T5]

pappatho, et al,

A flashing LED tool does not read the mileage on '96-'97 850 (to the best of my knowledge).

The mileage is read from the COMBI on pin 7 at 10400 baud. It's not even remotely humanly possible to operate a flashing LED tool that quickly.

You can read the mileage on a '96-'97 850 via an ELM327 device that's been setup properly to communicate with the KWPD3B0 protocol (ie, that Volvo special, ISO 9141-2 like, 5-baud init, 10400-baud normal comm, protocol that the '96-'97 850 COMBI, SRS, ABS, AW 50-42, Power Seats, Motronic 4.4, and Immobilizer use).

On the '96-'97 850, these flashing LED tools are used with Motronic 4.3 on pin 3, ECC on pin 6, and Cruise Control on pin 13.

It's unwise to use a flashing LED tool on a '96-'97 850 OBDII port's pin 7. I tried that in my initial searching for how to read the mileage, and learned to regret trying it (against my better judgment).

If anyone thinks they have discovered how to read 96-97 850 mileage via OBDII pin 7 using a flashing LED tool, please make a video of it, where the video records your year/model and shows both your button presses, the LED flashes, and a time source that increments by the second (or more often), simultaneously, so that we can determine what the frequency of button presses is to make it work. Then drive 31.0 - 32.0 miles (or km if you're in a metric country), record the exact mileage driven, down to the tenth of mile/km, repeat the process of attempting to read the mileage via the flashing LED tool while making a video which includes button presses, LED flashes, and time source, all viewable simultaneously, and show that the mileage read has incremented by 3 (or 4) to represent 30 (or 40) miles or km, whatever unit is appropriate for your car. Then repeat for a 3rd, 4th, 5th reading at longer distances in-between the readings, but where a video is no longer necessary (as long as the mileage reading attempts produce data consistent with the 1st 2 video recorded readings).

Edited: Include: a) "to the best of my knowledge" caveat, and b) request for undeniable video documentation if someone thinks that they can read vehicle mileage on a 97 850 using a flashing LED tool that pulses like the old under-the-hood A-B connectors.

esl_97_850_T5