Operation CHARM: Car repair manuals for everyone.
Home >> Dodge or Ram Truck >> 2012 >> RAM 3500 Truck 2WD L6-6.7L DSL Turbo High Output >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> U Code Charts >> U011A

U011A






U011A-LOST COMMUNICATION WITH EXHAUST GAS SENSOR MODULE





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Smart Oxygen Sensor Module (Smart O2 Module) is a smart device that receives information via the J1939 Datalink from the Powertrain Control Module (PCM). It provides the PCM with the oxygen concentration signal. It also performs its own diagnostics and reports failures back to the PCM over the J1939 Datalink.

- When Monitored:
Ignition on or engine started.

- Set Condition:
The Powertrain Control Module (PCM) does not receive a message from the Smart O2 Sensor Module in a calibrated amount of time.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. U011A ACTIVE
1. With the scan tool, read DTCs.

Is DTC U011A Active?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. Intermittent Condition Test

2. OTHER DTCs

NOTE: Repair any Voltage Low DTCs before proceeding with this test procedure.

NOTE: The J1939 Datalink is a BUS circuit which the PCM uses to communicate with the Turbo Actuator and O2 Sensor Module. If the J1939 Datalink is shorted or one of these components is internally shorted, communication will be lost and DTCs will set against BOTH of these components.

Are there lost communication DTCs present against BOTH of the components listed in the note above?

Yes

- Go To 6

No

- Go To 3

3. CHECK THE (F960) IGNITION FEED CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Disconnect the Smart O2 Sensor Module harness connector.
2. Turn the ignition on, engine not running.
3. Measure the voltage of all of the (F960) Ignition Feed circuits at the O2 Sensor Module harness connector.

Is the voltage within 1.0 Volt of battery voltage?

Yes

- Go To 4

No

- Using the wiring diagram as a guide, repair the (F960) Ignition Feed circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. CHECK THE (Z915) SMART O2 SENSOR MODULE GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Measure the resistance between ground and the (Z915) Smart O2 Sensor Module circuits at the O2 Sensor Module harness connector.

Is the resistance below 5.0 Ohms for all of the ground circuits?

Yes

- Go To 5

No

- Using the wiring diagram as a guide, repair the (Z915) Smart O2 Sensor Module Ground circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

5. CHECK THE J1939 DATALINK FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Measure the resistance of the J1939 Datalink (+) circuit between the Smart O2 Sensor Module harness connector and the PCM C2 harness connector.
4. Measure the resistance of the J1939 Datalink (-) circuit between the Smart O2 Sensor Module harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms for both measurements?

Yes

- Replace the Smart O2 Sensor Module.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Repair the J1939 circuit that measured above 5.0 Ohms for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

6. CHECK THE COMPONENTS ON THE J1939 DATALINK

NOTE: Disconnect only one component at a time during this next step. If the DTCs for the component that is STILL CONNECTED changes from active to stored, the component that was disconnected is faulty. If all of the DTCs remain active, then the disconnected component is not the problem. Reconnect each component before going on to the next one so that only one component is disconnected at a time.

1. Turn the ignition off.
2. Disconnect the Smart O2 Sensor Module harness connector. Cycle the ignition key on and off three times ending with the ignition on. Leave the ignition in the off position for 75 seconds each time.

NOTE: Monitor the status of the DTCs for the remaining connected components with the scan tool.

3. Turn the ignition off and reconnect the Turbo Actuator harness connector.
4. Disconnect the Turbo Actuator harness connector. Cycle the ignition key on and off three times ending with the ignition on. Leave the ignition in the off position for 75 seconds each time.

NOTE: Monitor the status of the DTCs for the remaining connected components with the scan tool.

Did the status of the DTCs change to stored for the component STILL CONNECTED when disconnecting any one of the components listed above?

Yes

- Replace the component that caused the DTC change from active to stored.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 7

7. CHECK THE J1939 DATALINK CIRCUITS FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Turbo Actuator, Smart O2 Sensor Module and the PCM C2 harness connectors.
3. Measure the resistance between ground and the J1939 Datalink (+) circuit at the PCM C2 harness connector.
4. Measure the resistance between ground and the J1939 Datalink (-) circuit at the PCM C2 harness connector.

Is the resistance above 10k Ohms for both circuits?

Yes

- Go To 8

No

- Repair the J1939 circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

8. CHECK THE J1939 DATALINK CIRCUITS FOR A SHORT
1. Measure the resistance between the J1939 Datalink (+) circuit at the PCM C2 harness connector and all other circuits in the PCM C2 harness connector.
2. Measure the resistance between the J1939 Datalink (-) circuit at the PCM C2 harness connector and all other circuits in the PCM C2 harness connector.

NOTE: Disregard any resistance between 50 and 70 Ohms between the J1939 (+) and the J1939 Datalink (-) pins.

Is the resistance above 10k Ohms for both circuits?

Yes

- Go To

No

- Repair the J1939 circuit for a short circuit.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

9. CHECK THE J1939 DATALINK CIRCUITS FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the J1939 Datalink (+) circuit between the Smart O2 Sensor Module harness connector and the PCM C2 harness connector.
2. Measure the resistance of the J1939 Datalink (-) circuit between the Smart O2 Sensor Module harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms for both circuits?

Yes

- Replace the Powertrain Control Module. Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Repair the J1939 circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

pro multis · About Operation CHARM