Test Step 6 - (K399) O2 SENSOR 2/2 HEATER CONTROL CIRCUIT OPEN

Fig 1: Measuring Resistance Of (K399) O2 Sensor 2/2 Heater Control Circuit Between O2 Sensor 2/2 Harness Connector And PCM C2 Harness Connector

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

• Turn the ignition off.
• Measure the resistance of the (K399) O2 2/2 Heater Control circuit from the O2 Sensor harness connector to the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes 

• Go to Test Step 7 - POWERTRAIN CONTROL MODULE (PCM) 

No 

• Repair the open in the (K399) O2 Sensor 2/2 Heater Control circuit.
• Perform the Powertrain Verification Test. Refer to PCM Verification Test (2009 - 2011) & PCM Verification Test (2012 & Up) .