A missed lap can come from the kart, the transponder, the detection loop, the activator, the decoder or the timing software. The quickest diagnosis is to decide whether the fault follows one kart or one timing line.
Identify the system before testing
Record the transponder model and unique ID, whether it is rechargeable or direct-powered, the decoder and loop equipment, and when the problem occurs. A rechargeable TR2 race transponder is not diagnosed in exactly the same way as a permanently powered TranX 140 rental-kart transponder.
If one kart is missing
- Check the transponder has power or charge and inspect its indicator state using the correct MYLAPS guide.
- Check the holder, wiring and connector for damage or intermittent contact.
- Confirm the transponder ID is correctly assigned in the timing software.
- Confirm mounting orientation and height against the manual. MYLAPS states that a TR2 Kart transponder should be vertical and no more than 30 cm above the ground.
- Pass a known-good kart over the same loop, then test the suspect transponder in a controlled way.
If every kart is missing at one loop
Inspect loop wire, joints, end box, coaxial cable, activator power and decoder input. Look for recent track work, cuts, crushed cables, water ingress, loose connectors or a power interruption. Compare the failing loop with a known-good timing line before replacing the decoder.
TR2-specific checks
For a rechargeable TR2, confirm registration, activation and subscription status in the Speedhive app. MYLAPS states a full charge takes about five hours and provides up to five days of battery backup. A direct-power model cannot be treated as a rechargeable unit.
Permanent rental-kart transponders
For a direct-powered unit, test supply voltage and ground under vibration, inspect the loom route and make sure the cable has not been pinched during engine or bodywork repairs. A transponder that works on the stand but drops out on track often needs wiring and connector checks before replacement.
RKP stocks the MYLAPS TranX 140 permanent rental-kart transponder, complete active timing-loop kit and rental-kart timing starter pack. Confirm the installed decoder, transponder type, loop width and system generation first.
Sources
Do not cut or modify timing-loop or transponder wiring until the installation manual and cable type have been confirmed.