MAF voltages and wiring [S70 2.5t 98r]

radek93 · Post by **radek93** » 08 Dec 2019, 04:02

I suspect that the flow meter is working poorly because it shows 3g / s. I have 0.8-0.9V in the flowmeter plug between pins 2 and 4. Pin 1 has 22 ohms resistance to ground. In the scheme pin go to ecu. Can I add ground directly from battery to the cable from pin 1? I suspect that the resistance causes reduced flow readings. It seems to me that if pin 1 in the flow meter is ground, the resistance should be 0

Post by **abscate** » 08 Dec 2019, 04:46

The line to the ECU is a signal line, not ground.

You have to be careful measuring resistances in ECU lines

3 grams per second is about right at idle

radek93 · Post by **radek93** » 08 Dec 2019, 05:24

In the program, autodata state that 1 volt is to be at idle. I have less. I put on a second used flowmeter and shows similarly. I washed him with isopropanol. Wash it with a dedicated spray? Second question, is tps giving ns idle 14% good? Measuring on a closed throttle comes out 0.8 volts and according to autodata 0.5 volts.

radek93 · Post by **radek93** » 08 Dec 2019, 08:57

abscate wrote: ↑08 Dec 2019, 04:46 The line to the ECU is a signal line, not ground.

You have to be careful measuring resistances in ECU lines

3 grams per second is about right at idle

https://www.google.pl/url?sa=t&source=w ... bKExFn_sL1

According to the description of the ecu mo 4.4 pins, pin number 1 is power ground and pin number 2 is signal ground. Pin 3 power supply and pin 4 plus signal. Why the power ground comes from ecu? Ecu use 3 lines to measure? Maybe I will try to remove the ecu and measure the resistance on the cable?