The port says what the car was built to tell a mechanic.
And nothing more. The emissions rules made a short list of values universal and left the rest optional, so what a plug-in unit can read depends on the vehicle's type and age far more than on the unit. Check yours before buying sixty of them.
- SAR 460
- SAR 170 more than Wired
- Under a minute
- No tools. Drivers fit their own.
- 7 tries
- At a last message, once it is pulled
- 4.8%
- Of a van battery, parked 30 days
What your vehicles will actually say
By type and age, never by make. Of the 11 combinations below, 3 are a clear yes, one says buy the cheaper unit, and the rest depend on the model — which we would rather check with you than discover on your invoice.
- Fault codes and warning lightalwaysMaintenance alerts the day the light comes on, with the code attached.
- Engine speedalwaysOver-revving and labouring in the behaviour score — invisible to a satellite.
- Coolant temperaturealwaysOverheating before it becomes a roadside job. In August, the alert that matters most.
- Vehicle identityusuallyThe unit notices when it has been moved to a different vehicle.
- Fuel levelsometimesFuel is whatever the receipts say.
- OdometersometimesCounted from the fix from the day it was fitted, offset to the dashboard once.
- Lifetime engine hoursrarelyCounted by the unit from engine speed, starting the day it went in.
- Traction battery chargeneverCharge is a guess from distance since the last plug-in.
- 12-volt batteryalwaysFlat-battery warnings. Read off the port's own power pin, so there is nothing to decode.
- SeatbeltsneverOn the body side of the car's gateway, not the diagnostic side. We will not pretend to read it.
- Doors and locksneverSame wall as the seatbelts. A door you need to know about wants a switch, and a switch wants a wired unit.
SAR 170 for the engine's warnings
Fault codes and engine data are dependable; fuel and distance are a coin toss. Worth it on vehicles you will keep for years. Send us the model and we will tell you which side of the coin it lands.
- Fault codes and warning light
- Engine speed
- Coolant temperature
- Vehicle identity
- SQ-OBD
- SAR 460
- SQ-WIRE
- SAR 290
5 of 11 values dependable on this vehicle. "Usually" means we would build on it; "sometimes" means we would check your model first.
Plugged in means it can be unplugged
A port is somewhere a knee, a mechanic or a driver can reach, and the unit cannot stop any of them. It can tell them apart, and it can make sure the last thing it says is where it was.
The workshop
Out inside a workshop geofence, in working hours, back in before the vehicle leaves.
A splitter cable, so the mechanic's scan tool gets a port of its own and ours never comes out.
Knees and cargo
A jolt on the accelerometer, then silence, usually mid-shift and nowhere in particular.
A short extension that lifts the unit out of the footwell and up behind the trim.
On purpose
Out of hours, away from any yard, and back in before the morning.
Nothing stops a hand. The gap has a start, a place and an end, and that is usually the conversation.
When it comes out, a 5-farad capacitor charged to 5 V holds 35 joules above the 3.3 V the radio needs. One attach and send in poor coverage costs about 4.5 joules. That is 7 attempts at a last message — and a capacitor, unlike a battery, does not mind a footwell in August.
A fuel gauge is not a meter
The fuel level on the port is the dashboard gauge, good to ±3–5%. On an 80-litre van tank that is 2.4 to 4.0 litres either way.
A driver taking 2 litres a day stays inside that every single day, which comes to 520 litres over 260 working days. The gauge catches the refuel that never happened. It does not catch a skim. A probe does, and a probe needs the Advanced unit.
A month in the airport car park
The diagnostic port is live with the ignition off, so the unit is always drawing something. Asleep, it takes 4 mA.
- 30 days
- 2.88 Ah
- Of 60 Ah
- 4.8%
If the battery was tired to begin with and falls to 11.8 V, the unit stops drawing altogether. It would rather go quiet than be the reason a van will not start.
Where the port runs out
Not for trucks
A heavy vehicle's diagnostic connector speaks a different protocol, and this unit does not speak it. The Wired unit tracks a truck; the Advanced reads one.
Some ports go quiet when parked
Newer vehicles close the port behind a gateway with the ignition off. Position keeps coming from the unit's own fix, and engine data resumes at the next start.
Electric vehicles vary by maker, not by year
Which is why the table above will not give them a verdict. If you are weighing electric vans, the electric fleet page starts from your routes rather than from the port.
It reports an unplug. It does not prevent one.
A splitter and an extension take the accidents out. Nothing takes out a driver who wants it out, and a unit that pretended otherwise would be selling you a feeling.