Diagnostic Test

2009 Jeep Compass Sport, 2.4 B, ED3, FWD, StandardSECTION Diagnostic Test
NOTE: Diagnose any CAN - C Communication DTCs before continuing.
  1. Turn the ignition off.
  2. If possible, allow the vehicle to sit with the ignition off for more than 480 minutes in an environment where the temperature is consistent and above - 7° C (19.4° F).
  3. Test drive the vehicle. The vehicle must exceed 48 km/h (30 mph) during the test drive. Do not cycle the ignition off when the test drive is completed.
  4. With a scan tool, select View DTCs.

    Is the status Active or Pending for this DTC?

    Yes 

    • Go to step  2

    No 

    • Go to step  1
  1. AMBIENT AIR TEMPERATURE 
    1. Turn the ignition off.
    2. Allow the vehicle to sit with the ignition off in an environment where the temperature is consistent and above - 7° C (19.4° F) until the engine coolant temperature is equal to ambient temperature.
    3. Turn the ignition on.
    4. With a scan tool, compare the AAT, ECT 2, and IAT sensor values.

      Is the Engine Coolant Temperature Sensor 2 value within 10° C (18° F) of the other two sensor values?

      Yes 

      No 

      • Go to step  2
  2. (K222) ECT 2 SIGNAL CIRCUIT SHORTED TO VOLTAGE 
    Fig 1: Checking ECT Sensor Circuit
    GC0100068Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the Engine Coolant Temperature Sensor 2 connector.
    3. Disconnect the Powertrain Control Module (PCM) connector.
    4. Turn the ignition on.
    5. Measure the voltage of the (K222) ECT 2 Signal circuit in the Engine Coolant Temperature Sensor 2 harness connector.

      Is there any voltage present?

      Yes 

      No 

      • Go to step  3
  3. (K222) ECT 2 SIGNAL CIRCUIT SHORTED TO GROUND 
    Fig 2: Checking ECT Sensor Circuit
    GC0100069Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Measure the resistance between ground and the (K222) ECT 2 Signal circuit in the Engine Coolant Temperature Sensor 2 harness connector.

      Is the resistance above 100 ohms?

      Yes 

      • Go to step  4

      No 

  4. (K222) ECT 2 SIGNAL CIRCUIT SHORTED TO THE (K915) SENSOR GROUND CIRCUIT 
    Fig 3: Checking ECT Sensor Circuit
    GC0100070Courtesy of CHRYSLER LLC
    1. Measure the resistance between the (K222) ECT 2 Signal circuit and the (K915) Sensor Ground circuit in the Engine Coolant Temperature Sensor 2 harness connector.

      Is the resistance above 100 ohms?

      Yes 

      • Go to step  5

      No 

  5. (K222) ECT 2 SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 4: Checking ECT Sensor Circuit
    GC0100071Courtesy of CHRYSLER LLC
    1. Measure the resistance of the (K222) ECT 2 Signal circuit between the Engine Coolant Temperature Sensor 2 harness connector and the Powertrain Control Module (PCM) harness connector.

      Is the resistance below 5.0 ohms?

      Yes 

      • Go to step  6

      No 

  6. (K915) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 5: Checking ECT Sensor Circuit
    GC0100072Courtesy of CHRYSLER LLC
    1. Measure the resistance of the (K915) Sensor Ground circuit between the Engine Coolant Temperature Sensor 2 harness connector and the Powertrain Control Module (PCM) harness connector.

      Is the resistance below 5.0 ohms?

      Yes 

      • Go to step  7

      No 

  7. ENGINE COOLANT TEMPERATURE SENSOR 2 
    Fig 6: Checking ECT Sensor Circuit
    GC0100073Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Connect the Powertrain Control Module (PCM) connector.
    3. Connect a jumper wire between the (K915) Sensor Ground circuit and the (K222) ECT 2 Signal circuit in the Engine Coolant Temperature Sensor 2 harness connector.
    4. Turn the ignition on.
    5. With the scan tool, read the Engine Coolant Temperature Sensor 2 signal voltage.

      Is the voltage below 1.0 volt with the jumper wire in place?

      Yes 

      No 

      • Go to step  8
  8. POWERTRAIN CONTROL MODULE (PCM) 
    1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Coolant Temperature Sensor 2 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. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
    5. Look for the data to change or for the DTC to reset during the wiggle test.
    6. Refer to any Technical Service Bulletins 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.