UK Haldex ECU Repairs Service Centre & Mail Order Parts

Connector Pins

A common fault with Gen 2 Haldex controllers is the connector pins in the back of the control unit that bite onto the oil pressure and temperature sensor spread open, and thus do not contact the sensor correctly, or the sensor has been fitted 180 degrees rotated incorrectly. This triggers the fault code 02249, and on later software versions it also triggers the 02248 valve code, and thus the 00003 (which always comes with 02248):-

02249 – Sensor for Oil Pressure and Oil Temperature (G347) 014 – Defective
00003 – Control Module 014 – Defective 
02248 – Valve for Controlling Clutch Operating Angle (N373) – 014 Defective

Exploded diagram showing the location of the oil pressure and temperature sensor (G347) being part number 10

Part 10 is the G347 Temp / Pressure sensor, it has a key notch that locates it into part 3 to ensure correct orientation.

There are two causes for this which can be established via the Output test with VCDS / ODIS / Diagnostic tool.

If the Sensor has been fitted 180 degrees rotated incorrectly then the pressure and temp values look like this:-

Results of an Output test with VCDS / ODIS diagnostic tool showing the readings when sensor has been installed incorrectly

But if the contacts are not connected you will get something like this:-

Results of an Output test with VCDS / ODIS diagnostic tool showing the readings when the contacts are not connected

The gaps between the contact sides need to be smaller that 0.8mm, using a feeler gauge or some other tool they can be checked to see if the gap is narrow enough to lock on, thus they lock onto the sensor like this:-

Example of a pressure sensor locked into pin contacts with the correct size gap

These contacts below are too spread out and will not contact the sensor correctly (right hand side) :-

Example of contacts which are spread out too much for sensor to connect

Zoomed in example showing a block with 4 pin connectors with one connector being OK and the other 3 no good

The second pin down is good but the other three are too spread open.

With a pair of tweezers or a fine pick, the pins can be bent past each other thus closing the gap, and afterwards they should look like this to function correctly.

Connector block with pin contacts which have been bent back into their originally designed position

If the sensor is actually defective, then the same issue can occur but it is very rare for the G347 sensor to fail, normally they are damaged due to forceful removal of the control unit when the bolts are corroded in and have to the cut etc to be removed. If the sensor fails naturally then the pressure reading tends to sit at zero and not respond to oil pressure.

Another cause of the G347 pressure sensor fault is where somebody fits a Gen 2 Haldex control unit to a Gen 4 coupling which has no sensor present to connect into.

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