B1002

B1002-A/C SWITCH REQUEST INPUT CIRCUIT HIGH (CCN)

B1002-A/C Switch Request Input Circuit High (CCN):

WHEN MONITORED
With the ignition on.

SET CONDITION
If the Instrument Cluster (CCN) detects voltage above 4.5 volts for 10 seconds on the (C105) HVAC MUX Control circuit.

POSSIBLE CAUSES
- (C105) HVAC MUX control circuit shorted to voltage
- (C105) HVAC MUX control circuit open
- (C955) HVAC MUX return circuit open
- A/C heater control
- Instrument cluster (CCN)

Diagnostic Test

1. VERIFY DTC B1002-A/C SWITCH REQUEST INPUT CIRCUIT HIGH IS ACTIVE

Turn the ignition on.
With the scan tool, erase CCN DTCs.
Turn the ignition off, wait 10 seconds, and turn the ignition on.
With the scan tool, read CCN DTCs.

Q: Does the scan tool display active: B1002-A/C SWITCH REQUEST INPUT CIRCUIT HIGH?

YES: Go To 2
NO: 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. Body Verification Test




2. CHECK THE (C105) HVAC MUX CONTROL CIRCUIT VOLTAGE AT A/C HEATER CONTROL C1 HARNESS CONNECTOR

Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
Measure the voltage of the (C105) HVAC MUX Control circuit.

Q: What is the voltage?

Below 4.8 Volts
Go To 3

4.8 to 5.2 Volts
Go To 4

Above 5.2 Volts
Go To 6




3. CHECK THE (C105) HVAC MUX CONTROL CIRCUIT FOR AN OPEN

Turn the ignition off.
Disconnect the Instrument Cluster C4 harness connector.
Measure the resistance of the (C105) HVAC MUX Control circuit between the A/C Heater Control C1 harness connector and the Instrument Cluster C4 harness connector.

Q: Is the resistance below 5.0 ohms?

YES: Replace the Instrument Cluster (CCN). Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Repair the (C105) HVAC MUX Control circuit for an open. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test




4. CHECK THE (C955) HVAC MUX RETURN CIRCUIT OPERATION

Turn the ignition off.
Using a 12-volt test light connected to 12 volts, back probe the (C955) HVAC MUX Return circuit in the A/C Heater Control C1 harness connector.

Q: Does the test light illuminate brightly?

YES: Replace the A/C-Heater Control. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 5




5. CHECK THE (C955) HVAC MUX RETURN CIRCUIT FOR AN OPEN

Measure the resistance of the (C955) HVAC MUX Return circuit between the A/C Heater Control C1 harness connector and the Instrument Cluster C4 harness connector.

Q: Is the resistance below 5.0 ohms?

YES: Replace the Instrument Cluster. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Repair the (C955) HVAC MUX Return circuit for an open. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test




6. CHECK THE (C105) HVAC MUX CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

Turn the ignition off.
Disconnect the Instrument Cluster C4 harness connector.
Turn the ignition on.
Measure the voltage of the (C105) HVAC MUX Control circuit.

Q: Is the voltage above 0.2 volts?

YES: Repair the (C105) HVAC MUX Control circuit for a short to voltage. Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace the Instrument Cluster (CCN). Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test