Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSJEEP2009COMPASS LIMITED, EDG, AUTOMATIC CVTREPAIR AND DIAGNOSISENGINE PERFORMANCESYSTEMDTCS P0122 TO P0222 (GAS)P0135-O2 SENSOR 1/1 HEATER PERFORMANCEDIAGNOSTIC TEST

2009 Jeep Compass Limited, EDG, Automatic CVT

Diagnostic Test

2009 Jeep Compass Limited, EDG, Automatic CVTSECTION Diagnostic Test

OXYGEN SENSOR 1/1 HEATER CONTROL OPERATION
1. Turn the ignition off.
  NOTE: Wait a minimum of 8 minutes to allow the sensor to cool down before continuing. The sensor voltage should stabilize between 2.47 and 2.52 volts.
2. Turn the ignition on.
3. With a scan tool, actuate the Oxygen Sensor 1/1 heater control.
4. With the scan tool, monitor 1/1 O2 Sensor Volts for at least 2 minutes.
  Does the voltage stay between 2.47 and 2.52 volts?
  
  Yes
  - Go to step 2
  No
  - Refer to the CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
OXYGEN SENSOR 1/1
1. Turn the ignition off.
  NOTE: Wait a minimum of 8 minutes to allow the sensor to cool down before continuing.
2. Disconnect the Oxygen Sensor 1/1 harness connector.
3. Measure the resistance of the O2 sensor heater element across the Oxygen Sensor 1/1 connector between the heater control terminal and the ground terminal.
  NOTE: The O2 heater element resistance should be measured at 70° F (21.1° C). The resistance value will vary at different temperatures.
  
  Is the resistance between 2.0 and 30.0 ohms?
  
  Yes
  - Go to step 3
  No
  - Replace the Oxygen Sensor 1/1 in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 1: Checking O2 Sensor Circuit
Courtesy of CHRYSLER LLC
1. Disconnect the Powertrain Control Module (PCM) harness connector.
2. Measure the resistance of the (K99) O2 1/1 Heater Control circuit from the Oxygen Sensor 1/1 harness connector to the Powertrain Control Module (PCM) harness connector.
  Is the resistance below 0.5 ohm?
  
  Yes
  - Go to step 4
  No
  - Repair the (K99) O2 1/1 Heater Control circuit for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(Z909) GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 2: Checking O2 Sensor Circuit
Courtesy of CHRYSLER LLC
1. Using a 12 volt test light connected to 12 volts, check the (Z909) Ground 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.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go to step 5
  No
  - Repair the (Z909) Ground circuit for an open circuit or high resistance.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
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
  - Repair as necessary.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
  - Perform the PCM VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .

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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.