In this weeks Tech Tip we’re going to be talking about the diagnostic LED lights that are on MicroTech ECU’s.
Judging by the tech emails we receive, there are quite a few people using our ECU’s who have no idea of the purpose of the LED’s & specifically what each one indicates.
Most of our ECU’s have 3x diagnostic LED‘s located on the end of the unit next to the handset port.
Below is a quick rundown of what each of the 3x LED’s are telling you.
The green LED serves the most basic function of the 3. It illuminates when the ECU is powered “on”.
The orange LED will flash each time the ECU receives a home signal from the crank sensor.
The orange LED is most commonly used to help diagnose problems with an engine that won’t start.
If the orange LED isn’t flashing, the ECU has no idea the engine is turning over, so there will be no spark or injector pulse (& without either of those not much is going to happen )
When this occurs, generally there will be a fault with the wiring to the crank sensor or a problem with the sensor itself.
The red LED flashes when there is a input error to the ECU.
There are 8x different inputs that can trigger an error.
Water Temp, Air Temp, TPS, MAP, Battery Voltage & Home, Reference & RPM input (the last 3x inputs all come from the crank sensor).
When the ECU recognizes a sensor error, that error will be logged to the ECU & can be viewed on the “error check” screen using the handset or laptop software (this is located on screen 33).
The red LED “DOES NOT” mean the ECU is faulty & you need to send it in to be repaired (this is a very common assumption).
It’s telling you that there is a problem with one of the “signals” going to the ECU.
Most experienced MicroTech tuners will find themselves using the diagnostic LED’s on a regular basis. A good understanding of what each one is telling you will speed up your fault finding process dramatically
Happy tuning guys
#techtuesday #microtechschool #tuningtips #injectingthefastest
