Guide · EFILive

EGT on EFILive

EFILive logs a 0 – 5 V exhaust gas temperature amplifier through the analog inputs on FlashScan V2, the older unit. FlashScan V3 and AutoCal V3 have no analog inputs, so they can't read an EG5 or EG12 directly. If you have a V2, this guide covers the wiring, a calculated PID that turns volts into °C, and logging.

Checked against EFILive's V8 reference manual, its knowledge base and the FlashScan V2 documentation, September 2026.

00What you need

• A FlashScan V2 (or the heavy-duty FlashScan HD), with EFILive V8 software and firmware kept current.
• An EG12. FlashScan V2 has no 5 V output, so the EG12 on switched 12 V is the simple choice. An EG5 would need its own 5 V supply.
• A Type K probe and a bung or O2-port adapter for it, bought to the specifications under Recommended to use with.
• A multimeter.

Electrical

01Pick an input

FlashScan V2 has four analog inputs, A1 to A4, on AD-2 screw-terminal plugs. Each reads 0 – 5 V at 10-bit resolution, isolated from the rest of the unit.

• Follow the + and − marks on the FlashScan: + is signal, − is signal ground.
• The inputs only work with 12 V on the OBD connector. USB power alone isn't enough.
• Stay inside the 0 – 5 V input range.

02Wire it

• Because the inputs are isolated, connect the − terminal to the EG's black wire, so FlashScan measures the signal against the amplifier's own ground.
• One ground point. The EG's black wire goes to vehicle ground near the module, and the FlashScan input's − terminal connects there too. Every 4 – 5 mV of offset between them reads as about 1 °C.
• An EG5 goes on a 5 V sensor supply only, never 12 V. It has no reverse-polarity protection either, so check red and black before you power up.
• Neither output can go much above 5 V. The EG5 can't rise above its own 5 V supply, and the EG12 is capped at about 5.3 V.

Probe side

• The thermocouple cable is cut square. Take the jacket back, strip the yellow and red, and splice yellow to the probe's + and red to −. The cable is Type K extension, so the splice can sit anywhere along its run.
• Check the polarity. A reversed probe reads right at room temperature, so once it is spliced, warm the probe's tip: the reading must rise. If it falls, swap the probe's two leads at the splices. On a probe whose leads are not marked, the − lead is the one a magnet sticks to.
• Need more reach? Extend from the probe end with Type K extension wire, never copper.
• Ungrounded probes only. An ohmmeter from either lead to the sheath should read open.
• Mount the module somewhere cool, on the cabin side of the firewall or an inner fender: under 50 °C for an EG5, under 100 °C for an EG12.

Software

03Set it up in EFILive V8

1. In EFILive V8, open [F2: Scan] → [F2: PIDs] and drag the external analog PID for your input (AD1 to AD4) into the selected PIDs.
2. Open [Config] → Calculated PIDs (Ctrl+K). Add a group, four characters or fewer, then add a PID in metric units (°C).
3. Click [Edit] and type return. Click your AD PID in the list on the right so EFILive inserts its exact name, then add *250 for an EG12 or *200 for an EG5. Click [Test]. Scripts are case-sensitive, and the AD PID must stay selected.
4. For standalone logging on the FlashScan itself, set A/D PIDs to Yes in the device settings so it records every external analog PID.

EFILive recommends its built-in editor over editing the calculated PID file by hand. The multiplier is the full-scale temperature divided by the full-scale voltage, from the calibration points above.

A dash means past that model's range.

04See it and log it

• Watch it on [F3: Data], [F4: Charts] or [F5: Gauges]. The Gauge Editor only lists selected PIDs.
• On the FlashScan's own screen, the reading stays in volts. Calculated PIDs aren't computed on the device, so convert with the table above.

Troubleshooting

The inputs read 0 V

Check that FlashScan has 12 V from the OBD connector; the inputs don't work on USB power. Keep EFILive current too: a 2020 V8 bug read the analog inputs as 0 V.

Readings are offset or drift

Ground offset. Put the input's − terminal on the EG's ground. If the inputs themselves are off, EFILive's Control Panel has Calibrate A/D, using stable 1 – 2 V and 3 – 5 V sources.

It reads near full scale on a cold engine

The probe is disconnected or open. Both modules drive their output high when the probe circuit is open, so an open probe reads hot, not cold.

The reading falls as the exhaust heats up

The probe's leads are reversed at the splices. A reversed probe reads right at room temperature, then falls toward 0 °C as its tip heats. Swap the probe's two leads.

The reading jumps with revs, fans or the alternator

You have a grounded probe, or the black wire is on chassis ground. Fit an ungrounded probe and use the sensor ground.

It reads high once the engine bay heats up

The module is mounted somewhere too hot, or there's copper wire between the probe and the module.