Manual Temperature Control

B210A - System Voltage Low

For a complete wiring diagram, refer to.

• When Monitored: With the ignition switch on.

• Set Condition: The A/C heater control has detected the system voltage is less than a calibrated value.






Test Step 1 - Verify the DTC is Active

• Diagnose any related Powertrain DTCs before continuing.

• Turn the ignition switch ON.

• With a scan tool, read and record DTCs.

• With the scan tool, clear DTCs.

• Turn the ignition switch OFF, and then ON.

• Using the scan tool, read DTCs.

Does the DTC reset?

Yes

• Go to Test Step 3 => [ Test Step 3 - Fused Ignition Switch Output (Run-Start) Circuit Open ]

No

• Go to Test Step 2 => [ Test Step 2 - Intermittent Condition ]

Test Step 2 - Intermittent Condition

• Check for any of the follow conditions:

• Poor wire to terminal connection

• Corroded terminals

• Backed out or loose terminals

• Broken wire internal to the insulation

• Dirty (partial) module ground

• With the ignition on, wiggle the related wires.

• Using a scan tool, read DTCs.

Does the DTC reset?

Yes

• Repair the wiring as necessary.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

No

• The conditions that caused this DTC to set are not active at this time. Test complete.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 3 - Fused Ignition Switch Output (Run-Start) Circuit Open

• Check the related fuses to the fused ignition switch output (Run-Start) circuit. If the fuse is found to be open repair the circuit for a short condition.

• Turn the ignition OFF.

• Disconnect the A/C heater control C1 harness connector.

• Turn the ignition ON.

• Using a 12 volt test lamp connected to ground, probe the fused ignition switch output (Run-Start) circuit in the A/C heater control C1 harness connector.

Does the test lamp illuminate brightly?

Yes

• Go to Test Step 4 => [ Test Step 4 - Check the A/C Heater Control ]

No

• Repair the fused ignition switch output (Run-Start) circuit for an open.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

Test Step 4 - Check the A/C Heater Control

• A dirty (partial) ground can cause abnormal conditions within a system. Make sure the module has a good ground before continuing.

• Turn the ignition OFF.

• Reconnect the A/C heater control C1 harness connector.

• While back probing, measure the voltage of the fused ignition switch output (Run-Start) circuit in the A/C heater control C1 harness connector.

• Start the engine.

• Using the scan tool, view battery voltage under data display in the engine category.

• Compare the voltage on the scan tool to the voltage reading on the voltmeter.

Is the voltage on the scan tool equal to the voltmeter reading within +/- 0.5 volt?

Yes

• Replace the A/C heater control.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test

No

• Repair the circuits that indicated the incorrect voltage.

• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test