B210D-84

B210D-84-BATTERY 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 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 battery voltage is lower than 8.0 volts 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 CHARGING SYSTEM 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 IF THE DTC IS ACTIVE
1. With the scan tool, read HVAC DTCs.

Is this DTC active?

Yes

- Go To 4

No

- Go To 7

4. CHECK THE (A417) FUSED B(+) CIRCUIT FOR AN OPEN




1. Ignition on, engine not running.
2. While back probing, measure the voltage of the (A417) Fused B(+) circuit in the A/C Heater Control harness connector.

Is the voltage below 9.0 volts?

Yes

- Repair the (A417) Fused B(+) circuit for an open or high resistance.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 5

5. CHECK (F921) FUSED IGNITION RUN CONTROL OUTPUT CIRCUIT FOR AN OPEN




1. Ignition on, engine not running.
2. While back probing, measure the voltage of the (F921) Fused Ignition Run Control Output circuit in the A/C Heater Control harness connector.

Is the voltage below 9.0 volts?

Yes

- Repair the (F921) Fused Ignition Run Control Output circuit for an open or high resistance.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 6

6. CHECK THE (Z911) GROUND CIRCUIT FOR AN OPEN




1. Turn the ignition off to the lock position.
2. Disconnect the A/C Heater Control harness connector.
3. Using a 12-volt test light connected to 12-volts, check the (Z911) Ground circuit.

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

Does the test light illuminate brightly?

Yes

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

No

- Repair the (Z911) Ground circuit for an open.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

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

Were there any problems found?

Yes

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

No

- Test complete.