B1083

B1083-HVAC MUX CIRCUIT HIGH

B1083-HVAC Mux Circuit High:

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
- Instrument cluster (CCN)
- A/C heater control

DIAGNOSTIC TEST

1. VERIFY DTC B1083-HVAC MUX 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: B1083-HVAC MUX CIRCUIT HIGH?

YES: Go To 2
NO: Check for an intermittent condition by inspecting the related wiring harness for chaffed, 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. Body Verification Test

2. CHECK (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
Replace the A/C Heater Control. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
Above 5.2 volts
Go To 4

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




Turn the ignition off.
Disconnect the Instrument Cluster C2 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 C2 harness connector.

Q: Is the resistance below 5.0 ohms?

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

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




Turn the ignition off.
Disconnect the Instrument Cluster C2 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 BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace the Instrument Cluster (CCN). Perform BODY VERIFICATION TEST - VER 1. Body Verification Test