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Old 29th December 2016, 11:37 AM
Mechcanico Lee Mechcanico Lee is offline
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Join Date: Jul 2015
Location: St Helens Haydock
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Great good work Ben ....sorry I should of said this in last post , with the orginal boost sensor with the plug plugged in check them voltages again .

Im happy with the atmospheric reading 1030mb or 999.8mb it's close enough it not an exact science ....it's only a tiny aneroid sensor internal to ecm .

See how with sensor unplugged there is 3 pins at 5 volts or thereabouts , one of them 5 volts is the sensor supply the other two 5 volts are coming from the ecm ....this system is called '5 volts pull down ' .......so plug the boost sensor back in and in therory 2 of them values will change make a note of this .

So the brown / blue judging from the colour code must be the earth ....you need to load test this wire with a bulb so we know it can carry some load .

So if we know 5 volt supply good ...earth good and the other two signal wires when you measure voltage at the plug with it connected and that is X you need to measure that at ecm plug .

The bit that clouds the whole diag is the unknown brand boost sensors ..... see the orginal boost sensor could be faulty but both the new sensors could be giving in correct readings ....there's a lot of Chinese parts out there that can cloud the whole diagnostic process and send you off on a tangent , with sensors we tend to use dealer parts , it just saves alot of ' re diagnosis ' .

Try these tests Ben and see how we get on .
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