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- Apr 22, 2018
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Another simple test. To verify pinout and operation of the transducer. I have spare one (sensor), so no need to remove existing one from the system (there should be a Schrader valve under the sensor, so you'll not loose the refrigerant, but who knows, maybe You don't have it, or it's leaky).
You put compressed air into the "sensor" and watch the readings. Compressor was set to 7 bar. And guess what's the reading...
So it's an absolute pressure transducer, it will read the atmospheric pressure (little bit off, maybe under "3 bar" mentioned in the eLearn it is not linear, plus A/D converter resolution is probably low, AC system is not a priority for ECU, other sensors are way more important). Therefore my 7,0 bar reads "8,0 bar" (7+1). Unplugged gives zero (and P0530 error in the ECU).
Verdict: healthy sensor + wiring + ECU. The PinOut in the eLearn (A/C system description and the plug) is wrong, both pictures! First (description of the AC system and transducer) is supply and output mixed (pins 2 & 3), second one (connector) is a mirror image, pins 1 and 2 swapped (supply and ground)...
You put compressed air into the "sensor" and watch the readings. Compressor was set to 7 bar. And guess what's the reading...
So it's an absolute pressure transducer, it will read the atmospheric pressure (little bit off, maybe under "3 bar" mentioned in the eLearn it is not linear, plus A/D converter resolution is probably low, AC system is not a priority for ECU, other sensors are way more important). Therefore my 7,0 bar reads "8,0 bar" (7+1). Unplugged gives zero (and P0530 error in the ECU).
Verdict: healthy sensor + wiring + ECU. The PinOut in the eLearn (A/C system description and the plug) is wrong, both pictures! First (description of the AC system and transducer) is supply and output mixed (pins 2 & 3), second one (connector) is a mirror image, pins 1 and 2 swapped (supply and ground)...
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