HVAC

B210A-SYSTEM VOLTAGE LOW

For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
With the ignition switch on.

- Set Condition:
The A/C Heater Control has detected the system voltage is low.





Diagnostic Test

1. VERIFY THE DTC IS ACTIVE
NOTE: 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 scan tool display this DTC as active?

Yes

- Go to 2

No

- The condition that caused this symptom is currently not present. 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. (F943) FUSED RUN-START RELAY OUTPUT CIRCUIT OPEN




NOTE: 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 shorted condition.

Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
Using a 12 volt test light connected to ground, probe the (F943) Fused Run-Start Relay Output circuit in the A/C Heater Control C1 harness connector.
Does the test light illuminate brightly?

Yes

- Go to 3

No

- Repair the (F943) Fused Run-Start Relay Output circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

3. CHECK THE A/C HEATER CONTROL
NOTE: 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 (F943) Fused Run-Start Relay Output 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 BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Repair the circuit(s) that indicated the incorrect voltage.
- Perform SKREEM VERIFICATION TEST. Vehicle Theft Security Verification Tests