B1001

B1001-A/C SWITCH REQUEST INPUT CIRCUIT LOW





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

- 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.





1. VERIFY DTC B1001-A/C SWITCH REQUEST INPUT CIRCUIT LOW IS ACTIVE
1. Turn the ignition on.
2. With the scan tool, erase DTCs.
3. Turn the ignition off, wait 10 seconds, and turn the ignition on.
4. 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. Body Verification Test.

2. CHECK FOR B1001-A/C SWITCH REQUEST INPUT CIRCUIT LOW WITH A/C HEATER CONTROL C1 HARNESS CONNECTOR DISCONNECTED




1. Turn the ignition off.
2. Disconnect the A/C Heater Control C1 harness connector.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Turn the ignition off, wait 10 seconds, and turn the ignition on.
6. 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.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. CHECK THE (C105) HVAC MUX CONTROL CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Disconnect the Instrument Cluster C4 harness connector.
3. 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 To 4

No

- Repair the (C105) HVAC MUX Control circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

4. CHECK THE (C105) HVAC MUX CONTROL CIRCUIT FOR A SHORT TO THE (Z936) GROUND CIRCUIT AND THE (C955) HVAC MUX RETURN CIRCUIT




1. Measure the resistance between the (C105) HVAC MUX Control circuit and the (Z936) Ground circuit in the A/C Heater Control C1 harness connector.
2. 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).
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair any circuits that are shorted to the (C105) HVAC MUX Control circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.