P0563
P0563-BATTERY VOLTAGE HIGH
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Powertrain Control Module (PCM) uses the Generator field duty cycle signal circuit or F-terminal circuit, to monitor the duty cycle of the generator. The Generator field duty cycle signal circuit connects to high side of the field windings in the Generator. A Pulse Width Modulated (PWM) high side driver in the voltage regulator turns the field windings ON and OFF. The PCM uses the PWM signal input to determine the Generator load on the engine. This allows the PCM to adjust the idle speed to compensate for high electrical loads. The PCM monitors the status of the generator field duty cycle signal circuit. When the key is in the RUN position and the engine is OFF, the PCM should detect a duty cycle near 0 percent. However, when the engine is running, the duty cycle should be between 5-95 percent.
- When Monitored:
With the ignition on. Engine RPM greater than 1000 RPM. With no other charging system codes set.
- Set Condition:
Battery voltage greater than 15.75 volts. One Trip Fault. Three good trips to turn off the MIL.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
Diagnostic Test
1. ACTIVE DTC
NOTE: Make sure the Battery is in good condition. Using the Midtronics Battery Tester, test the Battery before continuing.
NOTE: Inspect the vehicle for after market accessories that may exceed the Generator System output.
NOTE: Make sure the Generator drive belt is in good operating condition.
NOTE: Inspect the fuses in the PDC. If a fuse is open use the wire diagram/schematic as a guide, inspect the wiring and connectors for damage.
1. Ignition on, engine not running.
2. With a scan tool, read the active DTCs.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
2. GENERATOR OPERATION
1. Turn the ignition off.
2. Disconnect the Generator Field harness connector.
3. Using a 12-Volt test light connected to ground, probe the (K20) Generator Field Control circuit in the Generator Field harness connector.
NOTE: Make sure the test light is probing the circuit before actuating the Relay or a DTC may set and not allow the actuation.
4. Ignition on, engine not running.
5. Using the scan tool, actuate the Generator Field Control circuit.
Does the test light illuminate brightly and flash on and off?
Yes
- Verify that there is good pin to terminal contact in the Generator and Powertrain Control Module connectors. If OK, replace the Generator.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 3
3. CHECK THE (K20) FIELD CIRCUIT FOR A SHORT VOLTAGE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the (K20) Generator Field Control circuit at the Generator Field harness connector.
Is there any voltage present?
Yes
- Repair the (K20) Generator Field Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 4
4. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Generator and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Generator and Powertrain Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module (PCM). Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.