Is it enough to measure voltage at the battery while running for battery voltage calibration of VEMS? I realized I did it that way long ago. Never measured at the ecu harness Anybody done it that way? Should I even probe the ecu while motor is running?
Sitting here in the exhaust shop lobby bored lol. Getting the last half of thr exhaust made of straight pipe. Keeping other half with muffler for inspection Have to pay in cash too hah
1991 Audi 200q Holset 1991 Audi 200q Felbaum'd 1988 Audi 5000 TQ
88a5tq wrote:Is it enough to measure voltage at the battery while running for battery voltage calibration of VEMS? I realized I did it that way long ago. Never measured at the ecu harness Anybody done it that way? Should I even probe the ecu while motor is running?
Sitting here in the exhaust shop lobby bored lol. Getting the last half of thr exhaust made of straight pipe. Keeping other half with muffler for inspection Have to pay in cash too hah
What you can do is measure batt voltage while running on the battery terminals. Then shut off, disconnect the ECU and measure resistance between positive battery pole and the +12v pin in the ECU connector. Same for batt GND. If 0 ohm, you can use the voltage you measure at the battery and match it up when calibrating. That's the way I did it.
88a5tq wrote:Oh nice approach thanks for chiming in Chris! I'll try that.
No worries, but keep in mind when you calibrate the voltage in VEMS that you just have the key in ON position not running, otherwise the voltage is not stable.
