B210E-85

B210E-85-BATTERY VOLTAGE HIGH - SIGNAL ABOVE ALLOWABLE RANGE







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 battery voltage is higher than 17.0 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.

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

Is this DTC active?

Yes

- Go To 4

No

- Go To 6

4. CHECK (F921) FUSED IGNITION RUN CONTROL OUTPUT CIRCUIT




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.
3. With the scan tool, read HVAC voltage.

Does the voltage between the measured voltage and the voltage on the scan tool match ± 0.5 of a volt?

Yes

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

No

- Go To 5

5. CHECK (F921) FUSED IGNITION RUN CONTROL OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE




1. Turn the ignition off to the lock position.
2. Disconnect the A/C Heater Control harness connector.
3. Measure the voltage of the (F921) Fused Ignition Run Control Output circuit in the A/C Heater Control harness connector.

Is there any voltage present?

Yes

- Repair the (F921) Fused Ignition Run Control Output circuit for a short to voltage.
- Perform HVAC VERIFICATION TEST HVAC Verification Test.

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.