OBD-II Setup & Configuration

OBD-II Setup

KrispyGauge can run on a standard road car by reading data from the OBD-II port, instead of a aftermarket CAN bus. The setup is different from the aftermarket ecu install in two important ways: where you wire it, and what to expect from the data.

Will it work on my car?

Your vehicle needs to use CAN for OBD-II. Broadly, most cars from around 2008 onward do. Older vehicles often use K-line or other pre-CAN protocols, which aren't supported.

Check the supported vehicles list for makes and models confirmed working. If yours isn't listed it may still work — get in touch and let us know how you get on.

1. Set the ECU type first

Connect to the Web UI at http://4.3.2.1, go to Settings, and set ECU type to OBD.

Do this before anything else. Changing ECU type wipes your entire configuration — channels, thresholds, colours, keypad mappings, all of it. Set it first, then build your pages.

2. Wire into the OBD-II port

KrispyGauge has a pre-made OBD cable available, but otherwise you can splice to the back of your OBD connector.

The OBD-II port is a 16-pin connector, usually under the dash on the driver's side. The pins you need:

CAN H (YELLOW)Pin 6
CAN L (GREEN)Pin 14
GND (BLACK)Pin 4 or 5
12V (RED)See below

Power needs care. Pin 16 on the OBD port is permanently live — it does not switch off with the ignition. Wiring the gauge to it means the gauge stays powered when the car is parked and will slowly drain the battery. If you use the constant 12V from your OBD connector we recomend enabling Sleep mode on the Gauge Configuration to reduce power draw and to put the display to sleep when its not in use.

(We recommend) taking your 12V from a separate ignition-switched source (an accessory circuit behind the dash works well) such as radio acc, and using the OBD port only for CAN H, CAN L and ground.

Don't enable the termination resistor. The vehicle's own CAN bus is already terminated at both ends. Adding another resistor will interfere with the car's electronics.

3. Check for a live signal

Turn the ignition on. Some vehicles won't respond until the engine is actually running — if you see nothing at key-on, start the car before troubleshooting anything else.

What to expect from OBD data

OBD-II works differently from a aftermarket ecu's CAN. These ecu's broadcasts data continuously;
OBD-II is request-and-response — the gauge asks the car for each value and waits for a reply.

In practice that means:

• Slower updates. Fine for coolant temp and oil pressure; not the same live feel as a Aftermarket ECU RPM feed.
• Fewer channels. You get the standard OBD-II parameters your car chooses to expose, not the full set of ECU internals, so even though you may have a paramater available for Oil Pressure, your car may choose to not show it, and there is not much that can be done about that (for now.)

See the signal documentation for the channels available on OBD.

Troubleshooting

No data at all — confirm ECU type is set to OBD. Then check pins 6 and 14 aren't swapped, and try with the engine running.

Worked, then stopped — check whether another device is sharing the OBD port. Insurance dongles, GPS trackers and diagnostic tools can conflict with the gauge. Unplug them and retest.

Some channels blank — not every vehicle exposes every OBD parameter. A blank channel usually means your car doesn't publish it rather than a fault with the gauge.

If your vehicle isn't working and isn't on the supported list, email [email protected] with the make, model and year — it helps us grow the list.