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Home >> Dodge and Ram >> 2021 >> ProMaster 2500 >> Repair and Diagnosis >> Engine Performance >> System >> 3.6L - DTCS P000A To P0138 >> DTC Troubleshooting >> P0133-O2 Sensor 1/1 Slow Response >> Diagnostic Test
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Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    NOTE:

    Check for contaminants that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.

    NOTE:

    After the repairs have been made, verify proper O2 Sensor operation. If all the O2 Sensor voltage readings have not returned to normal, follow the diagnostic procedure for the remaining O2 Sensors.

    1. Start the engine.
    2. Allow the engine 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.

    3. With a scan tool, read the active DTCs.
      NOTE:

      It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.

      Is the DTC active or pending?

      Yes 

      • Go To  2

      No 

  2. CHECK THE EXHAUST SYSTEM FOR LEAKS 
    1. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to CHECKING THE EXHAUST SYSTEM FOR LEAKS .

      Were any exhaust leaks found?

      Yes 

      • Repair or replace the leaking exhaust parts as necessary.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  3
  3. CHECK THE (K41) O2 SENSOR 1/1 SIGNAL CIRCUIT FOR PROPER VOLTAGE 
    1. Turn the ignition off
    2. Disconnect the O2 Sensor 1/1 harness connector.
    3. Turn the ignition on.
    4. Measure the voltage between ground and the (K41) O2 Sensor 1/1 Signal circuit in the O2 Sensor 1/1 harness connector.

      Is the voltage between 4.1 and 5.0 volts?

      Yes 

      • Go To  4

      No 

      • Check the (K41) O2 Sensor 1/1 Signal circuit for a short to ground, open, or short to voltage. If OK, Go To  6
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  4. CHECK THE (K902) O2 SENSOR 1/1 RETURN CIRCUIT FOR PROPER VOLTAGE 
    1. Measure the voltage between ground and the (K902) O2 Sensor 1/1 Return circuit in the O2 Sensor 1/1 harness connector.

      Is the voltage at 2.5 volts?

      Yes 

      • Go To  5

      No 

      • Check the (K902) O2 Sensor 1/1 Return circuit for a short to ground, open, or short to voltage. If OK, Go To  6
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  5. CHECK THE O2 SENSOR 1/1 FOR PROPER OPERATION 
    NOTE:

    Check for signs of contaminants that may have damaged the O2 Sensor, such as contaminated fuel, unapproved silicone, oil and coolant.

    1. Using the appropriate SYSTEM WIRING DIAGRAM/schematic as a guide, inspect the wiring and connectors between the Oxygen Sensor 1/1 and the Powertrain Control Module (PCM).
      • Look for any chafed, pierced, pinched, or partially broken wires.
      • Look for broken, bent, pushed out or corroded terminals.
      • Verify that there is good pin to terminal contact in the O2 Sensor 1/1 and Powertrain Control Module connectors.
      • Perform any Service Bulletins that may apply.

      Were any problems found?

      Yes 

      No 

  6. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all PCM harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

    5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. With the scan tool, erase DTCs.
    9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    10. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
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