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 (C221) A/C Switch Sense circuit.

POSSIBLE CAUSES
- (C221) A/C switch sense circuit shorted to voltage
- (C221) A/C switch sense 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 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. Body Verification Test




2. CHECK (C221) A/C SWITCH SENSE 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 (C221) A/C Switch Sense 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 (C221) A/C SWITCH SENSE CIRCUIT FOR AN OPEN

Turn the ignition off.
Disconnect the Instrument Cluster C3 harness connector.
Measure the resistance of the (C221) A/C Switch Sense circuit between the A/C Heater Control C1 harness connector and the Instrument Cluster C3 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 (C221) A/C Switch Sense circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test




4. CHECK (C221) A/C SWITCH SENSE CIRCUIT FOR A SHORT TO VOLTAGE

Turn the ignition off.
Disconnect the Instrument Cluster C3 harness connector.
Turn the ignition on.
Measure the voltage of the (C221) A/C Switch Sense circuit.

Q: Is the voltage above 0.2 volts?

YES: Repair the (C221) A/C Switch Sense 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