Peugeot 405 Petrol (1988 - 1996) - Problem with crank position sensor

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Fri 10 Aug 2007 13:42
Problem with crank position sensor - track
Hoping someone can help me out. The engine in question is a xu10j4r as found in the 1999 peugeot 406, 2 litre 16v lump. gearbox is a be3 box as found in a 205 1.9 gti and the flywheel is that from a 405 mi16. Strange combination but all compatible with each other. I have 3 crank sensors available to me, all exactly the same part numbers etc, 1 is from my old car, 1 is from a friends car and 1 is brand spanking new. All of them read around 380 ohms resistance which is bang on the money according to autodata, problem is all of them only generate around 1.8 volts when cranking the engine but they are supposed to be around 4 - 8 volts according to autodata. My ecu isnt getting any information at all to say that the engine is cranking and therefore will not fire. I have checked the ecu and all is in order through out the input circuits and also the loom is consistent with only a 0.6 ohm resistance start to end. I need to know what may possibly be causing the low voltage issue. The position of the crank sensor is not adjustable but I am thinking maybe it is a problem with it being to far away from the flywheels ring gear?
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Fri 10 Aug 2007 15:23
problem with peugeot crank position sensor - Peter D
Are you saying this combination has never run? If the starter is gearbox mounted then the ring gears must be the correct diameter. Regards Peter
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Fri 10 Aug 2007 16:21
problem with peugeot crank position sensor - Screwloose
track

The loom from the CPS's plug back to the ECU has a resistance of 0.6 ohms? On which wire? That's way too high. Water gets in the connector under the coolant elbow; have the cables corroded?

Stick a blob of wax on the CPS, fit it and slowly turn the engine to verify the clearance is almost nowt. My latest pin-data gives 2.2v at idle/3.5v@3000 which is consistent with your cranking reading.
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Fri 10 Aug 2007 16:42
problem with peugeot crank position sensor - track
there is no corrosion on the cables as it is all brand new, Ive rechecked the resistance, it is 0.06 ohm, sorry I had made an incorrect mental note of it. I am now suspecting an ecu fault over the cps anyway as I have been over the wiring and cps readings with various people and they have to be correct for everyone els to agree.
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Fri 10 Aug 2007 16:59
problem with peugeot crank position sensor - Screwloose
track

OK; recap a bit. Is this an RFV engine code? [It'll be in the VIN.]

At key-on, does it prime the rail for a few seconds?

Does the fuel pump run when cranking?

What feeds have you got at the double-relay plug? The BB-code wires?

What feeds and earths do you have at the ECU?

Is the inertia switch OK?
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