B1847
B1847 - Sunroof Vent Switch Input Circuit High
For a complete wiring diagram, refer to.
Theory of Operation
The sunroof motor/module supplies a 12 volt supply circuit to the sunroof switch. When the switch is closed to any of the 3 sense circuits (open, close or vent), it sends that command back to the module.
• When Monitored: Whenever the sunroof module is awake.
• Set Condition: Whenever the module has determined that the vent switch has been applied for over 15 seconds, there is a short to voltage, a short to ground or an open on the sunroof vent switch sense circuit, this code will set.
Test Step 1 - Test for an Intermittent Condition
• Turn the ignition ON.
• With the scan tool, record and erase DTCs.
• Press and release the sunroof switch in all positions several times.
• Wait 30 seconds.
• With the scan tool, check for DTCs.
Does the scan tool display B1847 - Sunroof Vent Switch Input Circuit High?
Yes
• Go to Test Step 2
No
• The conditions that caused this code to set are not present at this time. Check the switch for any binding conditions and using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
Test Step 2 - Sunroof Switch Short
• With the scan tool, erase DTCs.
• Turn the ignition OFF.
• Disconnect the sunroof switch harness connector.
• Turn the ignition ON and wait 30 seconds.
• With the scan tool, check for DTCs.
Does the scan tool display B1847 - Sunroof Vent Switch Input Circuit High as active?
Yes
• Go to Test Step 3
No
• Replace the sunroof switch.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Test Step 3 - Sunroof Vent Switch Sense Circuit Short to Voltage
• To further diagnose the sunroof, it is necessary to lower or remove the headliner.
• Turn the ignition OFF.
• Lower the headliner to gain access to the sunroof motor/module connector.
• Disconnect the sunroof motor/module connector.
• Ensure the A - Pillar connector is connected before proceeding.
• Turn the ignition ON.
• Measure the voltage between the sunroof vent switch sense circuit and Ground.
Is the voltage more than 0.4 volts?
Yes
• Repair the sunroof vent switch sense circuit for a short to voltage.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 4
Test Step 4 - Sunroof Vent Switch Sense Circuit Short to Ground
• Ensure the A - Pillar connector is connected before proceeding.
• Turn the ignition OFF.
• Measure the resistance between ground and the sunroof vent switch sense circuit in the sunroof motor/module harness connector.
Is the voltage more than 0.4 volts?
Yes
• Repair the sunroof vent switch sense circuit for a short to ground.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 5
Test Step 5 - Sunroof Vent Switch Sense Circuit Open
• Ensure the A - Pillar connector is connected before proceeding.
• Measure the resistance of the sunroof vent switch sense circuit between the sunroof switch harness connector and the sunroof motor/module harness connector.
Is the resistance less than 5.0 ohms?
Yes
• Repair the sunroof vent switch sense circuit for a short to ground.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 6
Test Step 6 - Sunroof Vent Switch Sense Circuit Short to Sunroof Switch Supply Circuit
• Turn the ignition OFF.
• Disconnect the A-Pillar connector.
• Measure the resistance between the sunroof vent switch sense circuit and the sunroof switch supply circuit in the sunroof motor/module connector.
Is the resistance less than 10k ohms?
Yes
• Repair the sunroof vent switch sense circuit for a short to the sunroof switch supply circuit.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Replace the sunroof motor/module.
• Perform the sunroof position calibration. Perform the excessive force limitation calibration.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior