Playing with the OBD-ii... got the mileage?

[izubma]

I have a '97 Volvo 850 NA and have a stuck odometer.

I built the circuit almost how it was shown in the picture (without the resistor since the LED has a built in resistor) and cannot get the circuit to give me any readouts.

With the engine off and the circuit attached, the LED is on. When the key is set to the ignition or the ignition is turned off, the LED goes out. Clicking the button causes the LED to light up.

I followed the procedure to read the mileage in one of the referenced forum entries. Clicking the button 5 times does nothing other than light the LED with each press. Following this up by clicking the button in sequence 1-1-1 also does not cause it to blink according to the mileage counter.

Here are the parts I used from RadioShack followed by pictures of the circuit and the circuit attached to the OBDII connector:

Part Number 275-1547 SPST Mini Momentary Pushbutton Switch N.O contacts rated 3.0A at 125VAC, 1.5A at 250VAC
Part Number 276-0209 5mm Red LED 12VDC 20mA 1.5mcd with integrated resistor

Circuit connected to OBDII

IMG_20121125_164151.jpg (462.25 KiB) Viewed 781 times

Circuit Closeup of Connections

IMG_20121125_234618.jpg (382.35 KiB) Viewed 781 times

Please let me know if I've not built the circuit correctly and how to correctly press the buttons to try to get a readout (i.e. long press, short press, etc).

Thanks,
Mike

[izubma]

Correction to my previous post...

With the engine off and the circuit attached, the LED is on. When the key is set to the ignition or the ignition is turned on, the LED goes out. Clicking the button causes the LED to light up.