Testing - Open Circuits, Short to Ground or Positive, etc....

[DrPeter]

Testing as per fault code description:
by: DrPeter

When you have a fault code, like the ones below, it may be necessary to test the wiring and connections of the circuit before you
condemn a 'good' part and just throw another good part at the vehicle and expect a different result, we all know where that leads us.

The follow steps are intended as a guide to help you properly, quickly and accurately diagnose these types of wiring concerns, you must also
be on the lookout for any obvious connector issues, corrosion, damage, etc...


19559/P3103/012545 - Motor for Intake Manifold Flap (V157): Open or Short to Ground

17506/P1098/004248 - Intake Manifold Tuning Valve Position Sensor (G336): Open or Short to Plus


The first step is to become familiar with how the circuit works, locate a factory wiring diagram and identify the suspect component and see how it is wired.

Note: Ask yourself this, if you do not know how the V157-Motor for intake flap is wired, how can you properly test it, right?
What wire goes where? What wire is the power? Signal return, etc.?






Testing for Short to Ground.

Prerequisites:
- Ignition is turned off
- Disconnect the component(s) connector(s)
- Check wiring diagram and make sure no other components are on the circuit
- Disconnect the controller connector
Testing details:
- Set Digital Volt Ohm Meter (DVOM) to DC Voltage
- One DVOM meter probe to battery positive (+)
- Other probe to wire connection that is being tested (either end)
- Wiggle the harness
- Voltage is less than 0.2-Volts is acceptable
Repair details:
- Search and find the wire short and repair
- Or install an overlay harness




Testing for Short to Positive.

Prerequisites:
- Ignition is off
- Disconnect the component(s) connector(s)
- Check wiring diagram and make sure no other components are on the circuit
- Disconnect the controller connector
Testing details:
- Set Digital Volt Ohm Meter (DVOM) to DC Voltage
- One DVOM meter probe to battery negative (-)
- Other probe to wire connection that is being tested (either end)
- Wiggle the harness
- Voltage is less than 0.2-Volts is acceptable
Repair details:
- Search and find the wire short and repair
- Or install an overlay harness



Testing for Open Circuits.

Prerequisites:
- Ignition is off
- Disconnect the component(s) connector(s)
- Check wiring diagram and make sure no other components are on the circuit
- Disconnect the controller connector
Testing details:
- Set Digital Volt Ohm Meter (DVOM) to Ohm setting
- DVOM meter probes each end of the wire to be tested
- Wiggle the harness
- Resistance of 3-Ohms or less is acceptable
Repair details:
- Search and find the open/damaged wire and repair
- Or install an overlay harness




Testing for Wire Shorted to Other Wires.

Prerequisites:
- Ignition is off
- Disconnect the component(s) connector(s)
- Check wiring diagram and make sure no other components are on the circuit
- Disconnect the controller connector
Testing details:
- Set Digital Volt Ohm Meter (DVOM) to Ohm setting
- DVOM meter probe to first wire to be tested (either end)
- DVOM meter probe to other wire to be tested (either end)
- Wiggle the harness
- Resistance of 9-MOhm or more is acceptable
Repair details:
- Search and find the wire short and repair
- Or install an overlay harness



For more information about the use of a DVOM please see the following links:

http://assets.fluke.com/appnotes/automotive/beatbook.pdf

http://www.electronics-lab.com/articles/multimeter_tutorial/

http://support.fluke.com/find-sales/Download/Asset/1260898_6116_ENG_M_W.PDF

 

[Andy]

Another good resource (hat tip: Jef):
https://learn.sparkfun.com/tutorials/how-to-use-a-multimeter

 

[WuMutien]

Might this thread be a sticky?

 

[Chericon]

Whats the controller connector? I take it the component connector would be the connection to the component in question. In my case its the evap purge calve

 

[Chericon]

What is the controller connector?

 

[Uwe]

Component Connector is the connector "plug" where the component (switch, sensor, actuator) plugs into the car's wiring harness.

Controller Connector is is the connector "plug" where the control module in question plugs into the car's wiring harness.

In some cases, control modules (and less commonly, components) may have more than one connector.

-Uwe-

 

[TdiBlacky]

Testing for Short to Positive.

Prerequisites:
- Ignition is off
- Disconnect the component(s) connector(s)
- Check wiring diagram and make sure no other components are on the circuit
- Disconnect the controller connector
Testing details:
- Set Digital Volt Ohm Meter (DVOM) to DC Voltage
- One DVOM meter probe to battery negative (-)
- Other probe to wire connection that is being tested (either end)
- Wiggle the harness
- Voltage is less than 0.2-Volts is acceptable
Repair details:
- Search and find the wire short and repair
- Or install an overlay harness

I'm trouble shooting the following fault:

00562 - Sensor for oil level / Temperature (G266) 010 - Open or Short to Plus

I'm trying to apply the above instructions but I don't understand how there can be any volts, even 0.2 volts if you disconnect the component connector plug and the module connector plug and also the ignition is off. Surely there should be no volts in this scenario?

 

[Uwe]

I'm trouble shooting the following fault:

00562 - Sensor for oil level / Temperature (G266) 010 - Open or Short to Plus

I'm trying to apply the above instructions but I don't understand how there can be any volts, even 0.2 volts if you disconnect the component connector plug and the module connector plug and also the ignition is off. Surely there should be no volts in this scenario?

Post a snippet of the wiring diagram for this sensor please.

-Uwe-

 

[TdiBlacky]

Post a snippet of the wiring diagram for this sensor please.

-Uwe-

I don't have a wiring diagram for it yet, not sure if I can find one. It's a 1.9Tdi BXE engine code, mk v golf if that helps. Where is the oil level / temp sensor on the engine?

 

[Uwe]

If you don't have a wiring diagram or know where the sensor is, it's really pretty difficult to help you trouble-shoot it.

May I suggest that you register for and then pay for the minimum-length eRWin subscription and grab all the stuff specific to your car?

-Uwe-

 

[Jack@European_Parts]

When in an area of the unknown, try to get RTFB as aforementioned, always check all fuses & one at a time; consider the use of a tone generator to trace.

Then load or light a track, verifying the track can carry current.........