B1001-A/C SWITCH REQUEST INPUT CIRCUIT LOW (CCN)
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the ignition on.
- Set Condition:
If the Instrument Cluster (CCN) detects voltage below 0.55 volts for 10 seconds on the (C105) HVAC MUX Control circuit.
| Possible Causes |
| (C105) HVAC MUX CONTROL CIRCUIT SHORTED TO GROUND |
| (C105) HVAC MUX CONTROL CIRCUIT SHORTED TO (Z936) GROUND CIRCUIT |
| (C105) HVAC MUX CONTROL CIRCUIT SHORTED TO (C955) HVAC MUX RETURN CIRCUIT |
| INSTRUMENT CLUSTER (CCN) |
| A/C HEATER CONTROL |
Diagnostic Test
1. VERIFY DTC B1001–A/C SWITCH REQUEST INPUT CIRCUIT LOW IS ACTIVETurn the ignition on.
With the scan tool, erase DTCs.
Turn the ignition off, wait 10 seconds, and turn the ignition on.
With the scan tool, read DTCs.
Does the scan tool display active: B1001–A/C SWITCH REQUEST INPUT CIRCUIT LOW?
Yes
- Go To 2
No
- The condition that caused this symptom is currently not present. 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. Repair as necessary.
- Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
2. CHECK FOR B1001–A/C SWITCH REQUEST INPUT CIRCUIT LOW WITH A/C HEATER CONTROL C1 HARNESS CONNECTOR DISCONNECTED
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
With the scan tool, erase DTCs.
Turn the ignition off, wait 10 seconds, and turn the ignition on.
With the scan tool, read DTCs.
Does the scan tool display: B1001–A/C SWITCH REQUEST INPUT CIRCUIT LOW?
Yes
- Go To 3
No
- Replace the A/C Heater Control in accordance with the Service Information.
- Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
3. CHECK THE (C105) HVAC MUX CONTROL CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off.
Disconnect the Instrument Cluster C4 harness connector.
Measure the resistance of the (C105) HVAC MUX Control circuit between ground and the A/C Heater Control C4 harness connector.
Does the ohm meter read open circuit?
Yes
- Go To4
No
- Repair the (C105) HVAC MUX Control circuit for a short to ground.
- Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
4. CHECK THE (C105) HVAC MUX CONTROL CIRCUIT FOR A SHORT TO THE (Z936) GROUND CIRCUIT & THE (C955) HVAC MUX RETURN CIRCUIT
Measure the resistance between the (C105) HVAC MUX Control circuit and the (Z936) Ground circuit in the A/C Heater Control C1 harness connector.
Measure the resistance between the (C105) HVAC MUX Control circuit and the (C955) HVAC MUX Return circuit in the A/C Heater Control C1 and C4 harness connectors.
Does the ohm meter read open circuit?
Yes
- Replace the Instrument Cluster (CCN) in accordance with the Service Information.
- Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Repair any circuits that are shorted to the (C105) HVAC MUX Control circuit.
- Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).