Troubleshooting

Organised by what you are looking at. Most of what follows comes back to the ignition being in accessory rather than on, so start there if you are in a hurry.

Nothing appears when I scan

The app is looking and nothing has answered. After fifteen seconds it stops saying Looking for your adapter… and starts listing the reasons, because by then one of them is true.

The ignition is on, not just accessory. The port has no power in some vehicles until it is.

The adapter is pushed fully into the port. A partly seated adapter can power up and still not connect.

Bluetooth is on for this device. Obvious, and it happens.

The scan keeps running while you check, so an adapter that wakes up late still appears without you starting over.

One more thing worth knowing: do not pair the adapter in your phone’s own Bluetooth settings. DriveDecode connects to it directly. A system pairing can hold the link open so the app cannot claim it. If the adapter is listed there, choose forget this device and scan again from inside the app.

Adapter out of range

Move closer to the adapter and check that it's plugged in.

The Bluetooth link could not be established or was lost. Usually the phone is further from the car than you think, or the adapter lost power when the ignition went off.

Adapter not supported

This doesn't look like a compatible OBD-II adapter.

Whatever answered is not speaking the protocol the app expects. If you tapped the wrong device in the list, go back and pick again by the ID on the tile.

Adapter stopped responding

The adapter didn't reply. Check the connection and try again.

The link opened and then went quiet mid-conversation. Unplug the adapter, plug it back in, and try again. That forces a clean start.

Bluetooth is off

Turn on Bluetooth in Settings, then try again.

Your phone’s Bluetooth, not the app’s.

Connected but it says no vehicle

Waiting for the car. Just turn the ignition on.

This is the most common one, and it is not an error. The adapter is awake and the engine computer is not answering.

Almost always the ignition is off or only in accessory: accessory power wakes the adapter but not the computer. Turn the key to on, or press start without your foot on the brake. You do not need to tap anything, because the app is watching and will move on by itself the moment the car responds.

If the engine is genuinely running and it still fails, unplug the adapter and plug it back in, which forces a fresh protocol search.

Couldn’t read your car

This appears on the Codes tab when a scan fails, with a line saying which of the above happened: out of range, stopped responding mid-read, Bluetooth off, or the adapter not answering the way it should. Pull down on the list to try again once you have dealt with it.

Descriptions need an internet connection

Your codes are fine. The explanations are not, because they come from us and the phone has no signal.

Every code number is still there, grouped correctly. Tap Retry descriptions when you have signal and they fill in without rescanning the car.

A gauge shows two dashes and never fills in

Your car does not report that sensor. Every vehicle publishes a different subset, and the list a car advertises is often longer than the list it answers. The app keeps asking, so the reading appears the moment the car starts answering, which on a hybrid may be when the petrol engine restarts.

Nothing to fix.

Live gauges look dimmed, or frozen

Live polling pauses when you leave the Live tab and resumes when you return. If a gauge looks stale, check you are actually on that tab.

Readings update slowly

How fast the numbers move depends on your adapter and on how many modules the app is waiting on. Some vehicles have several that answer slowly, and every reading in a group waits its turn.

Use the Custom group with only the readings you need, or open a single reading on its own screen, which polls as fast as the link allows. Press and hold the Live title for Connection health to see what the link is actually doing.

A reading looks wrong for my car

The app reports what the vehicle publishes, without correcting it. Some vehicles report a sensor in units or with a scaling that does not match what you would expect, and a few report a value they do not actually measure.

If a number looks implausible, compare it against a related one before believing either. Coolant temperature against intake air temperature on a cold engine is a good sanity check: they should be close.

Clearing codes did not fix the warning light

It was never going to. Clearing erases the memory of the fault, not the fault. If the condition is still present the computer finds it again within a drive or two.

Chapter seven has the detail, including why permanent codes stay.

The battery check says charging is low

Often normal. Many newer vehicles deliberately reduce charging voltage under light load to save fuel. Run it again with the headlights and blower on: if it climbs, nothing is wrong. Chapter ten has the rest.

Which adapters work

DriveDecode is built and tested against DriveDecode OBD-II Bluetooth adapters, and those are the ones we can vouch for. The scan does not filter by name, so third-party adapters will appear in the list and many of them work.

What we cannot promise for those is the detail: protocol reporting, firmware information, connection health and the timing-sensitive checks are written against behaviour we have verified on our own hardware.

WiFi adapters are supported too. Join the adapter’s network first, then turn WiFi on under Settings, then Vehicle connection.

Still stuck

Settings, then Help & about, then Help & troubleshooting has the same answers offline, in the car, with no signal.

If none of it fits, contact support. Tell us the vehicle, what the app said, and where in the connection it stopped. The Technical details disclosure on a failed connection screen has text you can select and paste, and it saves a round of questions.