156 1.9 diesel 2001 cam sensor fault.

[sparki1]

Evning all.
                This simple fault I cant come up with an answer for, The 156 jtd in question has had a new belt done at a local Alfa specialist but brings up a code for cam sensor error. I check sensor output ...nothing. and the car is a bad starter. supply voltage and earth on pins 1 and 3 of the plug, scope pin 2 and on crank you see and occasional burst of life and then it starts. Most of the time however there is nothing.
When the engine does start there is still no output from pin 2 of the sensor. Tried cutting the wire incase signal is getting squashed but still no trace.? 2nd new sensor and trigger wheel fitted, all tests and results the same! aggggggh!

                     Thanks.

[laldog]

What do you mean cam sensor error? My bettting is the timing is out and the code you are getting is relating to a synch error.

[sparki1]

Timing yse would flag cam code but the alfa garage assure me it is spot on, but as there is no output from the sensor, even when it is running this would be the main reason the code is being generated would it not?   

[sparki1]

Can any one say for sure the voltage across pins 1&3 is supposed to be? 5 or 12volt? clutching at straws here, perhaps it should be 5 and my ecu is putting out 12v?

[laldog]

If it is a hall effect 5volts it should be,i can check at work in the morning.

[TopGun]

Phase sensor is a hall effect type and is driven off the exhaust camshaft.
Should register a signal as soon as the engine rotates on the starter
Phased to cylinder No.1
Sensor should output a square wave signal from 0V (earth) to approx 4.5V
Supply voltage to the sensor NBV at harness T1 (disconnected) ignition on

[laldog]

http://www.camshaftsensors.co.uk/Products.aspx?Man=ALFA%20ROMEO&Mod=156%20Saloon%20From%2009/97%20to%2009/2005&Ser=156%20(932)%201.9%20JTD%20(932A2B,%20932A2C)%20Diesel&Year=05/01%20to%2009/05&BHP=85&HP=115&CC=1910&Cylinders=04&Valves=8&VID=16584&e1=937A2000&e2=937A2.000

Is this yours?

[sparki1]

supply voltage i have but no output except an occasional burst of life which usually results in engine firing into life.
The Alfa garage has fitted two genuine sensors, the last time at my request with a new cam trigger wheel. The owner has now informed us he bought it with this problem and is hoping his insurance will pay the resulting bills! so I have stopped looking at it!