How to Choose the Right Power Supply for Foxflash

 POWERSUPPLY INFO!

Since this is asked quite a lot frequently when it comes with foxflash programmer so the post here is about this power supply issue.

Why?
Instability or undervoltage can cause programming interruptions, corrupted reads/writes, or worse — bricking the ecu (so dont underestimate this, you dont want extrabricked ecus because of your not providing good voltage and amps ).

remember that undervoltage is the main reason why you will fail on some ecus, not the tool itself. undervoltage can be fatal in some cases and that ecu is not anymore recoverable.
ALSO keep in mind that overpowering ecu is just as bad as undervoltage. you will end up killing the ecu , so play in area that is considered safe 12v-14.5v say tops.

WHAT YOU ACTUALLY NEED FOR BENCH ECU WORK?
So when doing bench programming of ECUs like MD1, the ECU needs a stable automotive-like 12 V DC supply. It usually won’t get enough or stable power from a simple USB (no way) adapter — you want a laboratory-grade or automotive bench power supply with ADJUSTABLE output and enough current (amps) capability.

Most professional bench setups use good quality regulated DC supply set around 12–14.5 V (we emulate healthy engine on idle or good battery+alternator combo) and enough amps to have some headroom when ecu powerside "spikes" during reads/writes.

Say a Typical automotive ECUs consume in the range of about 500 mA to 2 A within during normal operation.
Remember that certain ecus internal operations (e.g., CAN transceivers, bench communication hardware, boot loader initialization) can cause current spikes, so ensure enough headroom on your currentside (amps).

So What kind of power supply to go for, too many options?
Laboratory grade fully adjustable and regulated & controlled even source of voltage & amps.

Stability & Protection
Prefer regulated supplies with short-circuit protection, current limiting, and low ripple (important).
Linear power supplies provide cleaner power, but quality switched-mode supplies (bench lab units) can work well if stable and good quality.
adjustable in range of say 0–30volts and 5+ amps is needed (prefer 10A so you have some headroom in your settings). So when doing older ecus you can safely set TOPRANGE in current to 5A, on newer ecus i would say 8A topend, remember its just the ecu were powering here NOT the entire car.

POLARITY MATTERS!!
do NOT connect power source + and — wrong way, you will end up murdering your ecu. So start with checking polarity first and then the datalines can high low, kline (on older) and gpt (emulated cranckshaft signal. with all the rest you can play around in (meaning datalines) BUT dont mess around with powerside, thats considered a BAD idea.

I got my bench power supply now, where to aim?
Set Voltage First: Adjust your supply to ~13.5 V DC before connecting to the ECU.
Current Limit: Start with a safe limit (e.g., 5 A), and only raise if your bench setup (cables, adapters) demands more NOT BEFORE!!
Stable Wiring: Use a quality bench harness or distribution box so the ECU sees steady power.
Monitor: If your supply has a display, watch for sudden voltage dips during programming — those can interrupt flash reads/writes. so eyeball displays during write/read, if it needs more you can see that.

Whatkind of power/current range used on what ecus?
EDC15
Idle / powered 0.15–0.40 A
Read 0.25–0.60 A
Write / flash 0.40–0.90 A
Short peaks/spikes ~1.0–1.5 A
 — 
EDC16
Power-up / idle 0.4–0.7 A
Read (OTB or bench) 0.6–1.0 A
Write / flash 0.9–1.8 A
Short peaks/spikes ~2.0–2.5 A
 — 
EDC17
Power-up / idle 0.6–1.0 A
Read (bench / boot) 0.8–1.3 A
Write / flash 1.2–2.5 A
Short peaks ~3.0 , A sometimes 3.5A
 — 
MED17
Power-up / idle 0.5–0.9 A
Read (OTB / bench) 0.7–1.2 A
Write / flash 1.0–2.2 A
Short peaks/spiking ~2.5–3.0 A
 — 
MD1/MG1
Operating StateTypical Current
Power-up / Idle 0.3–0.6 A
Read (bench) 0.6–1.0 A
Write / Flash 0.8–1.5 A
Short Peaks Up to ~2.0 A
NOTE! These ecus spike a lot during read/writecycles.

Credit to STG file tuning.