U1149

U1149 - Lost Communication With Multifunction Switch - Steering Control Module






For a complete wiring diagram, refer to.

• When Monitored: With the ignition ON.

• Set Condition: The cluster does not receive information from the steering control module.






Test Step 1 - Check for an Active DTC

• Before proceeding with this diagnostic process, verify the proper connection of the SCM C1 and C2 harness connectors. A loose connection at these connectors will cause this DTC to set.

• Turn the ignition OFF.

• Gently pull the SCM C1 and C2 connector harnesses to verify the locking tab is fully engaged. If the connector locking tabs are not fully engaged, push to seat the connector locking tabs.

• Turn the ignition ON.

• Wait 30 seconds.

• With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

• Go to Test Step 2 => [ Test Step 2 - LIN Bus Circuit ]

No

• The condition that caused this code to set is not present at this time. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.

• Perform Body Verification Test. Refer to => Non
- DTC Based Diagnostics. Body Interior

Test Step 2 - LIN Bus Circuit

• Turn the ignition OFF.

• Disconnect the steering control module C1 and C2 harness connectors.

• Turn the ignition ON.

• Measure the voltage of the LIN bus circuit at the SCM C1 and C2 harness connectors.

Is the voltage above 5 volts?

Yes

• Replace the steering control module.

• Perform Body Verification Test. Refer to => Non
- DTC Based Diagnostics. Body Interior

No

• Go to Test Step 3 => [ Test Step 3 - LIN Bus Circuit Open ]

Test Step 3 - LIN Bus Circuit Open

• Turn the ignition OFF.

• Disconnect the cluster C2 harness connector.

• Measure the resistance of the LIN bus circuit at the SCM C1 and C2 harness connectors.

Is the resistance below 10K ohms?

Yes

• Replace the cluster.

• Perform Body Verification Test. Refer to => Non
- DTC Based Diagnostics. Body Interior

No

• Repair the LIN bus circuit for an open.

• Perform Body Verification Test. Refer to => Non
- DTC Based Diagnostics. Body Interior