P0562 Code: System Voltage Low — Causes and Diagnosis

Quick Answer

P0562 means a control module detected system voltage below its calibrated limit. A discharged or failing battery is common, but the code can also come from loose or corroded connections, a charging fault, excessive cable resistance, a slipping drive belt, a parasitic drain, or a module power or ground problem. Save the freeze frame and note which module stored the code. Charge and test the battery before replacing it, then test the complete charging circuit under load.

Code definition	System Voltage Low
Typical severity	Moderate to high. Low voltage can stall the engine, prevent starting, and disable brake, steering, transmission, or stability-control functions.
Most useful first tests	All-module scan, battery state of charge and health, connection inspection, charging output, and loaded voltage-drop tests
Frequent mistake	Replacing the alternator or battery from one voltage reading without testing charge state, cable losses, module location, and the OEM charging strategy

What P0562 Means

Every control module needs stable low-voltage power. When supply voltage falls below the threshold and duration programmed by the manufacturer, one or more modules may store P0562. The event can occur while cranking, idling with heavy electrical loads, driving, or after the vehicle has sat with a drain. Freeze-frame data can show engine speed, module voltage, temperature, and load at the moment of failure.

The module that stores P0562 matters. On some vehicles the engine control module reports it. On others, a brake, transmission, body, steering, or hybrid power-control module may store the code because voltage at that module fell low even though battery-post voltage appeared acceptable. A poor ground or high-resistance connector can create a local voltage loss.

Modern smart-charging systems vary alternator output according to battery state, temperature, deceleration, and electrical demand. A single running-voltage rule does not fit every vehicle. Hybrids and electric vehicles may use a DC/DC converter instead of a belt-driven alternator to support the 12-volt system. Use the charging specification and test mode for the VIN.

Symptoms of Low System Voltage

• The battery, charging, check-engine, ABS, stability-control, or steering warning appears.
• The starter turns slowly, clicks, or does not operate.
• The engine stalls, hesitates, or enters reduced-power mode.
• Headlamps flicker or dim and accessories reset.
• The transmission shifts harshly because a controller has entered a default mode.
• Several communication and module-performance codes appear together.
• The problem is worse in cold weather or after the vehicle sits.

A vehicle can also store P0562 with no current symptom after transport, long storage, repeated short trips, or a jump-start event. Code status, battery test results, and whether the fault returns separate a past discharge from an active electrical fault.

Common Causes

1. The 12-volt battery is discharged, sulfated, internally damaged, too small for the application, or near the end of its service life.
2. Battery terminals, cable crimps, fuse-block connections, engine grounds, or body grounds are loose, corroded, or heat damaged.
3. The alternator, voltage regulator, DC/DC converter, rectifier, or control circuit cannot maintain the commanded output.
4. The accessory drive belt, tensioner, or pulley slips and reduces alternator speed.
5. A parasitic draw from a module that will not sleep, aftermarket equipment, a light, or a damaged circuit discharges the battery.
6. The battery-current sensor or intelligent battery sensor has a wiring, installation, or calibration problem.
7. A high electrical load exceeds available charging output at idle, especially with a weak battery or poor connection.
8. A control-module software issue or internal fault sets the code. This is less common than battery, connection, and charging problems.

Diagnose P0562 in This Order

1. Scan every control module and save the report before clearing codes. Record the module that stored P0562, code status, freeze frame, and companion faults such as P0560, P0563, U-codes, generator-control codes, or battery-sensor codes.
2. Check the VIN for service bulletins, recalls, and software updates. Some OEM bulletins direct technicians to specific grounds, fuse blocks, harness routes, or battery test conditions.
3. Inspect the battery case, terminal seating, cable crimps, ground straps, high-current fuses, alternator connector, and drive belt. Look for swollen cables, green corrosion under insulation, loose fuse-block studs, damaged aftermarket wiring, and signs of heat.
4. Measure battery state of charge and recharge it with the correct charger when needed. Then run the OEM battery health or conductance test at the relevant ambient temperature. A discharged battery that accepts a charge and passes testing does not need replacement merely because P0562 was stored.
5. Measure voltage at the battery during key-on, cranking, idle, raised engine speed, and heavy electrical load. Compare the readings with the OEM procedure. On smart systems, use the prescribed scan-tool command or charging test rather than waiting for a fixed voltage.
6. Perform loaded voltage-drop tests on the positive cable and the ground path. Measure from the actual battery post, not only the clamp, and test at the affected module when the wiring diagram permits. Resistance that looks insignificant on an ohmmeter can create a large drop under starter or charging current.
7. Test alternator or DC/DC converter output, control command, current, and AC ripple to the manufacturer's specification. An alternator can produce acceptable no-load voltage and still fail with headlights, blower, defroster, and other loads operating.
8. If the battery repeatedly discharges, perform the OEM parasitic-draw test after every module has entered sleep mode. Preserve keep-alive power and monitor wake events as directed. Remove unsupported aftermarket devices and verify that the draw falls within the vehicle specification.
9. Test module powers and grounds before programming or replacement. After repair, clear the codes, complete battery registration or relearn if required, run several start cycles, and confirm that P0562 and related communication faults do not return.

Brand and OEM Differences

OEM example	What the official information shows
General Motors full-size SUVs	GM bulletin PIT6347A addresses P0562 and P0606 stored in the brake system control module on certain 2022 to 2025 Escalade, Suburban, Tahoe, and Yukon models. GM notes a link to cold temperature and lower battery state of charge, then directs technicians to test the battery, inspect cables and fuse blocks, check the charging system, and test for parasitic draw.
FCA vehicles after transport	FCA case S2108000086 describes some new vehicles arriving with low 12-volt charge and P0562. The OEM procedure calls for charging and testing the battery. It states that a discharged battery is unlikely to be bad when it accepts charge and passes the test.
Chrysler charging and programming	Chrysler bulletin 08-013-15 says normal charging-system diagnostics must be completed when P0562 or P0563 is present before following its body-control-module software procedure. This prevents a calibration update from being used as a substitute for electrical testing.

Repair Cost Factors

Cost depends on the failed component, cable access, battery type, required registration and diagnostic time. Test the complete charging circuit before approving a battery, alternator, DC/DC converter or control module.

P0562 FAQ

Related Information

If low voltage appears beside network faults, read the U0073 control-module communication guide. The OBD-II code basics guide explains freeze frame and code status.