U1149-LOST COMMUNICATION WITH MULTI-FUNCTION SWITCH
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the ignition on.
- Set Condition:
The Cluster does not receive any LIN Bus messages from the SCM.
| Possible Causes |
| (D506) LIN BUS CIRCUIT OPEN |
| (F202) FUSED IGNITION SWITCH OUTPUT (RUN/START) CIRCUIT OPEN |
| (A411) FUSED B+ (I.O.D.) CIRCUIT OPEN |
| (Z936/Z937) GROUND CIRCUIT OPEN |
| SCM |
Diagnostic Test
1. CHECK FOR AN ACTIVE DTCTurn the ignition on.
With the scan tool, record and erase DTCs.
Wait 30 seconds.
With the scan tool, read DTCs.
Does the scan tool display this DTC as active?
Yes
- Go To 2
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 - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
2. (D506) LIN BUS CIRCUIT OPEN
Turn the ignition off.
Disconnect the Steering Column Module C1 harness connector.
Turn the ignition on.
Measure the voltage of the (D506) LIN BUS circuit.
Is the voltage above 5 volts?
Yes
- Go To 3
No
- Repair the (D506) LIN BUS circuit for an open
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
3. (F202) FUSED IGNITION SWITCH OUTPUT (RUN/START) CIRCUIT OPEN
Measure the voltage of the (F202) Fused Ignition Switch Output (RUN/START) circuit.
Is the voltage above 10 volts?
Yes
- Go To 4
No
- Repair the (F202) Fused Ignition Switch Output (RUN/START) circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
4. (A411) FUSED B+ (I.O.D.) CIRCUIT OPEN
Measure the voltage of the (A411) Fused B+ (I.O.D.) circuit.
Is the voltage above 10 volts?
Yes
- Go To 5
No
- Repair the (A411) Fused B+ (I.O.D.) circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
5. (Z936/Z937) GROUND CIRCUIT OPEN
Measure the resistance between ground and the (Z936–MTX)/(Z937–ATX) Ground circuit.
Is the resistance below 10K ohms?
Yes
- Replace the SCM in accordance with the service information.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)
No
- Repair the (Z936–MTX)/(Z937–ATX) ground circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)