Diagnostic Test

2009 Jeep Compass Limited, EDG, Automatic CVTSECTION Diagnostic Test
  1. DTC IS ACTIVE 
    1. Start the engine and allow it to reach normal operating temperature.
      WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
    2. With the scan tool, select View DTCs.

      Is the status Active for this DTC?

      Yes 

      • Go to step  2

      No 

  2. (K99) O2 1/1 HEATER CONTROL CIRCUIT SHORTED TO VOLTAGE 
    Fig 1: Checking O2 Heater Control Circuit
    GC0099727Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the Oxygen Sensor 1/1 connector.
    3. Disconnect the Powertrain Control Module (PCM) connector.
    4. Turn the ignition on.
    5. Measure the voltage of the (K99) O2 1/1 Heater Control circuit in the Oxygen Sensor 1/1 harness connector.

      Is there any voltage present?

      Yes 

      No 

      • Go to step  3
  3. (K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 2: Checking O2 Heater Control Circuit
    GC0099725Courtesy of CHRYSLER LLC
    1. Measure the resistance of the (K99) O2 1/1 Heater Control circuit between the Oxygen Sensor 1/1 harness connector and the Powertrain Control Module (PCM) harness connector.

      Is the resistance below 5.0 ohms?

      Yes 

      • Go to step  4

      No 

  4. OXYGEN SENSOR 1/1 
    Fig 3: Checking O2 Heater Control Circuit
    GC0099726Courtesy of CHRYSLER LLC
    1. Connect the Powertrain Control Module (PCM) connector.
    2. Turn the ignition on.
    3. With the scan tool, actuate the Oxygen Sensor 1/1 control to the ON (100%) position.
    4. Using a 12 volt test light connected to ground, check the (K99) O2 1/1 Heater Control circuit in the Oxygen Sensor 1/1 harness connector.
      NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
    5. With the scan tool, actuate the Oxygen Sensor 1/1 control to the OFF (0%) position.
    6. Using a 12 volt test light connected to ground, check the (K99) O2 1/1 Heater Control circuit in the Oxygen Sensor 1/1 harness connector.
      NOTE: The test light should not be illuminated.

      Is the test light illuminated and bright with the actuator ON (100%) and not illuminated with the actuator OFF (0%)?

      Yes 

      No 

      • Go to step  5
  5. POWERTRAIN CONTROL MODULE (PCM) 
    1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 and the Powertrain Control Module (PCM).
    2. Look for any chafed, pierced, pinched or partially broken wires.
    3. Look for broken, bent, pushed out or corroded terminals.
    4. Refer to any Technical Service Bulletins (TSBs) that may apply.

      Were any problems found?

      Yes 

      No 

RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.