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B210A-84





B210A-84-SYSTEM VOLTAGE LOW - SIGNAL BELOW ALLOWABLE RANGE

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The A/C Heater Control constantly monitors battery and ignition voltage as well as battery voltage derived from BUS communication to ensure proper operation. If the voltage to the controller is out of range it could cause damage to the controller or its respective components. If the voltage of either circuit drops below or rises above a predetermined calibration a DTC will set.

- When Monitored:
With the ignition on.

- Set Condition:
If the controller system voltage or ignition voltage broadcast over the BUS is lower than monitored controller voltage the for period of 30 seconds.





Always perform the HVAC Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.

1. CHECK FOR TIPM DTCs
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.

Are there any Totally Integrated Power Module (TIPM) DTCs present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.

No

- Go To 2

2. CHECK FOR POWERTRAIN CONTROL MODULE DTCs
1. With the scan tool, read DTCs.

Are there any Powertrain Control Module (PCM) charging system DTCs present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.

No

- Go To 3

3. CHECK FOR HVAC DTCs
1. With the scan tool, read HVAC DTCs.

Is the DTC B210D-84-BATTERY VOLTAGE LOW - SIGNAL BELOW ALLOWABLE RANGE present also?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.

No

- Go To 4

4. CHECK IF THE DTC IS ACTIVE
1. With the scan tool, read HVAC DTCs.

NOTE: It can take up to 30 seconds or more for this DTC to mature.

Is this DTC active?

Yes

- Go To 5

No

- Go To 6

5. CHECK IF OTHER CONTROLLERS ARE REPORTING AN OVER VOLTAGE CONDITION
1. With the scan tool read DTCs.

Are any other controllers reporting an over voltage condition?

Yes

- Perform the appropriate diagnostic procedure.

No

- Replace and program the A/C Heater Control.
- Perform HVAC VERIFICATION TEST HVAC Verification Test.

6. CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. With the scan tool, check the Environmental Data to help identify the conditions in which the DTC was set.
3. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
4. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, partially broken wires.
5. Check the connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.
6. Wiggle the wiring and connectors while checking for shorted and open circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform HVAC VERIFICATION TEST HVAC Verification Test.

No

- Test complete.