Engine Code
P0562-BATTERY VOLTAGE LOWP0562-Battery Voltage Low:
WHEN MONITORED:
The engine running. The engine speed greater than 1000 RPM.
SET CONDITION:
Battery voltage is 1 volt less than desired voltage for a set period of time. One Trip Fault. ETC light is flashing.
POSSIBLE CAUSES
- Resistance in the (A1) battery positive circuit
- Resistance in the generator case ground
- Generator operation
- (K20) Generator field control circuit open
- (K20) Generator field control circuit shorted to ground
- Open fuse link
- (Z20) Ground circuit open
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. ACTIVE DTC
NOTE:
- Make sure the Battery is in good condition. Using the Midtronics Battery Tester, test the Battery before continuing.
- Inspect the vehicle for after market accessories that may exceed the Generator System output.
Turn the ignition off.
NOTE:
- Make sure the generator drive belt is in good operating condition.
- Inspect the fuses in the IPM. If an open fuse is found, use the wire diagram/schematic as a guide, inspect the wiring and connectors for damage.
Ignition on, engine not running.
With the scan tool, read DTCs.
Q: Is the DTC active at this time?
YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Component Tests and General Diagnostics
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. (A1) B+ CIRCUIT HIGH RESISTANCE
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE PULLEYS, BELTS, OR FAN. DO NOT WEAR LOOSE CLOTHING. FAILURE TO FOLLOW THESE INSTRUCTIONS CAN RESULT IN PERSONAL INJURY OR DEATH.
NOTE: Make sure all wires are clear of the engine's moving parts.
Measure the voltage between the (A1) B+ Terminal at the Generator and the Battery + Post.
Start the engine.
Q: Is the voltage above 0.4 of a volt?
YES: Repair the excessive resistance in the (A1) B+ circuit between the Generator and Battery. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 3
3. GENERATOR CASE GROUND HIGH RESISTANCE
Ignition on, engine not running.
Start the engine.
Allow the engine to reach normal operating temperature.
NOTE: Make sure all wires are clear of the engine's moving parts.
Measure the voltage between the Generator case and Battery ground post.
Q: Is the voltage above 0.1 of a volt?
YES: Repair excessive resistance in the Generator Ground between the Generator Case and Battery ground side. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4
4. GENERATOR OPERATION
Turn the ignition off.
Disconnect the Generator Field harness connector.
Using a 12-volt test light, jump it across the Generator Field harness connector.
Ignition on, engine not running.
With the scan tool, actuate the Gen Field Control circuit.
Q: Does the test light illuminate brightly and flash on and off?
YES: Replace the Generator. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 5
5. (K20) GENERATOR FIELD CONTROL CIRCUIT OPEN
Turn the ignition off.
Disconnect the C2 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
Measure the resistance of the (K20) Gen Field Control circuit from the Generator harness connector to the appropriate terminal of the special tool #8815.
Q: Is the resistance below 5.0 ohms?
YES: Go To 6
NO: Repair the open in the (K20) Gen Field Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
6. (K20) GENERATOR FIELD CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K20) Gen Field Control circuit in the Generator Field harness connector.
Q: Is the resistance below 100 ohms?
YES: Repair the short to ground in the (K20) Gen Field Control circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 7
7. (Z20) GROUND CIRCUIT OPEN
Using a 12-volt test light connected to 12-volts, probe the (Z20) Ground circuit in the Generator Field harness connector.
Q: Does the test light illuminate brightly?
YES: Go To 8
NO: Repair the open in the (Z20) Ground circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
8. PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Q: 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. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test