Diagnostic Test

WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
NOTE:
A new rear O2 Sensor along with an aging front O2 Sensor may cause the DTC to set. Review the repair history of the vehicle before continuing.

NOTE:
If an O2 Sensor DTC set along with the Catalytic Converter Efficiency DTC diagnose the O2 Sensor DTCs before continuing.

NOTE:
Check for contaminants that may have damaged the O2 Sensor and Catalytic Converter: contaminated fuel, unapproved silicone, oil and coolant, repair necessary.
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. With the scan tool, read 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 at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to STANDARD PROCEDURE .
VISUALLY INSPECT CATALYTIC CONVERTER
1. Inspect the Catalytic Converter for the following damage:
  - Damage Catalytic Converter, dents or holes.
  - Severe discoloration caused by overheating the Catalytic Converter.
  - Catalytic Converter broke internally.
  - Inspect both ends of the converter, inlet and outlet.
  - Leaking Catalytic Converter.
  Were any problems found?
  
  Yes
  - Replace the Catalytic Converter. Repair the condition that may have caused the failure. Refer to CONVERTER, CATALYTIC, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 3
CHECK THE (K902) O2 SENSOR 1/1 RETURN CIRCUIT VOLTAGE

Fig 1: Measuring Voltage On O2 Sensor Return Circuit In O2 Sensor Harness Connector
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the O2 Sensor 1/1 harness connector.
3. Turn the ignition on.
4. Measure the voltage on 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 4
  No
  - Go To 5
CHECK THE (K904) O2 SENSOR 1/2 RETURN CIRCUIT VOLTAGE

Fig 2: Measuring Voltage On O2 Sensor Return Circuit In O2 Sensor Harness Connector
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the O2 Sensor 1/2 harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K904) O2 Sensor 1/2 Return circuit in the O2 Sensor 1/2 harness connector.
  Is the voltage at 2.5 volts?
  
  Yes
  - Go To 10
  No
  - Go To 7
CHECK THE (K902) O2 SENSOR 1/1 RETURN CIRCUIT FOR A SHORT TO GROUND

Fig 3: Measuring Resistance Between Ground And O2 Sensor Return Circuit In O2 Sensor Harness Connector
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Measure the resistance between ground and the (K902) O2 Sensor 1/1 Return circuit in the O2 Sensor 1/1 harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (K902) O2 Sensor 1/1 Return circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (K902) O2 SENSOR 1/1 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
2. Measure the resistance of the (K902) O2 Sensor 1/1 Return circuit from the O2 Sensor 1/1 harness connector to the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 9
  No
  - Repair the (K902) O2 Return Upstream circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (K904) O2 SENSOR 1/2 RETURN CIRCUIT FOR A SHORT TO GROUND

Fig 4: Measuring Resistance Between Ground And O2 Sensor Return Circuit In O2 Sensor Harness Connector
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the O2 Sensor 1/2 harness connector.
3. Measure the resistance between ground and the (K904) O2 Sensor 1/2 Return circuit in the O2 Sensor 1/2 harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 8
  No
  - Repair the (K904) O2 Sensor 1/2 Return circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK THE (K904) O2 SENSOR 1/2 RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
2. Measure the resistance of the (K904) O2 Sensor 1/2 Return circuit from the O2 Sensor 1/2 harness connector to the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 9
  No
  - Repair the (K904) O2 Sensor 1/2 Return circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Sensor 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 Sensor and the Powertrain Control Module connectors.
  - Perform any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Replace and program the Powertrain Control Module in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECKING THE EXHAUST SYSTEM FOR LEAKS
1. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS test procedure. Refer to DIAGNOSIS AND TESTING .
  Were any exhaust leaks found?
  
  Yes
  - Repair or replace the leaking exhaust parts as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 11
ENGINE MECHANICAL CONDITION
1. Check the exhaust for excessive smoke caused by an internal problem in the engine.
  Is an engine mechanical condition present?
  
  Yes
  - Repair the engine mechanical condition as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 12
AGING O2 SENSOR
1. A new Downstream O2 Sensor along with an aging Upstream O2 Sensor may cause the DTC to set.
2. Review the vehicles repair history.
  Has the Downstream O2 Sensor been replaced without replacing the Upstream O2 Sensor?
  
  Yes
  - Replace the front O2 Sensor as necessary. Refer to CONVERTER, CATALYTIC, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Go To 13
CATALYTIC CONVERTER
If there are no possible cause remaining, view repair.

Repair
- Replace the Catalytic Converter. Refer to CONVERTER, CATALYTIC, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .