Test Step 3 - (K99) O2 SENSOR 1/1 HEATER CONTROL CIRCUIT OPEN

Fig 1: Measuring Resistance Of (K99) O2 Sensor 1/1 Heater Control Circuit Between Oxygen Sensor 1/1 Harness Connector And PCM C2 Harness Connector

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

• Disconnect the PCM C2 harness connector.
• Measure the resistance of the (K99) O2 Sensor 1/1 Heater Control circuit from the O2 Sensor 1/1 harness connector to the PCM C2 harness connector.

Is the resistance below 0.5 Ohm?

Yes 

• Go to Test Step 4 - (Z902) O2 SENSOR 1/1 HEATER GROUND CIRCUIT OPEN 

No 

• Repair the excessive resistance in the (K99) O2 Sensor 1/1 Heater Control circuit.
• Perform the Powertrain Verification Test. Refer to PCM Verification Test (2009 - 2011) & PCM Verification Test (2012 & Up) .