P0562 Code: Subaru Impreza (2017-2023) - Causes, Symptoms & Fixes

2017-2023 Subaru Impreza – OBD-II Code P0562 Diagnostic Guide

Important data note based on available NHTSA data for this exact make/model/year/issue: No NHTSA complaints were found for this combination, and no recalls were found in the NHTSA database. This means the following guide relies on general OBD-II and Subaru-specific electrical knowledge, not on documented complaints or recalls for this exact vehicle in the provided data. Data limitations should be kept in mind.

CODE MEANING AND SEVERITY

• Code meaning:

  • P0562 = System Voltage Too Low. The Powertrain Control Module (PCM) detects that the vehicle’s electrical system voltage is below the acceptable range for a sustained period.

• Severity:

  • High to moderate. Low system voltage can cause misfires, sensor readings to be unreliable, and various modules to operate incorrectly. In some cases, the engine may run poorly, stumble, stall, or fail to start. It can also trigger other electrical fault codes. Because the PCM and many control modules rely on steady voltage, a persistent low voltage condition can lead to drivability and reliability issues if not corrected.

COMMON CAUSES ON SUBARU IMPREZA

• Weak or aging 12V battery (most common)
• Alternator not charging properly or failing
• Corroded, loose, or damaged battery terminals and clamps
• Poor or corroded battery ground to chassis/engine block
• Faulty or aging wiring harness between the alternator, battery, and PCM (including fusible links or power supply circuits)
• Blown fuses or fusible links that feed the PCM or other critical modules
• Excess parasitic electrical draw or heavy loads (e.g., aftermarket devices) when the vehicle is off
• PCM power supply issues or grounding problems specific to the vehicle’s electrical architecture

SYMPTOMS

• Check Engine Light (MIL) illuminated
• Battery light or charging system warnings on the dash
• Engine may run rough, stumble, misfire, or feel weak
• Hard starting or no-start condition
• Dimming or flickering lights (especially with engine starting or when under load)
• Accessories (radio, HVAC, headlights) may operate erratically or intermittently
• Inconsistent idle or erratic engine behavior when voltage is dropping

DIAGNOSTIC STEPS

Note: Work safely around a live electrical system. If you’re not comfortable diagnosing electrical issues, seek a qualified technician.

A. Confirm the code and related data

• Use an OBD-II scanner to verify P0562 and check for any related codes (other battery/charging or PCM codes that may accompany it).
• Perform a live data readout if possible to observe voltage in real time, both with the engine off and with the engine running.

B. Check battery condition

• With engine off, measure battery voltage. Target: 12.6 V to 12.8 V for a healthy, rested battery.
• With engine running, measure charging voltage at the battery terminals. Target: approximately 13.8 V to 14.5 V as the alternator charges.
• If the resting voltage is low or the charging voltage is not within the target range, the battery or alternator is suspect.

C. Inspect battery and electrical connections

• Visually inspect terminals for corrosion, looseness, or damaged clamps.
• Clean corrosion if present and ensure tight, clean connections.
• Check for damaged or frayed wiring at the battery terminals and along the main power and ground paths.

D. Test charging system and alternator

• Perform an alternator output test (either with a proper load test or a professional charging system test) to confirm the alternator is providing proper voltage under varying loads (lights on, AC on, etc.).
• If the alternator is not producing sufficient voltage or current, replace or repair the alternator.

E. Inspect main power and grounding routes to PCM

• Verify the main 12V power feed to the PCM is present and within spec (check fuses and fusible links feeding the PCM power rail).
• Inspect ground circuits for the PCM and related modules (engine block to chassis grounding strap, battery negative to engine/chassis, and any known Subaru grounding points). A high resistance or open ground can cause voltage-related faults.
• Look for damaged or chafed wiring harness insulation near the harnesses that run to the PCM, alternator, and battery.

F. Check fuses, fusible links, and protective wiring

• Confirm all relevant fuses and fusible links are intact and properly seated.
• Replace any blown fuse with an identical rating and inspect the associated circuit for faults if it blows again.

G. Rule out parasitic draw

• With the ignition off, perform a parasitic draw test to see if a device or wiring path is pulling excessive current that could prematurely discharge the battery and contribute to low voltage conditions.
• If an abnormal draw is found, isolate and repair or replace the responsible device or wiring.

H. Rule out false-positive or intermittent voltage issue

• If voltage readings appear normal but the code persists, consider performing an ECM/PCM reset or software update if available, and re-check voltage after the reset.
• Consider rechecking all readings after a few drive cycles to rule out intermittent faults.

I. Drive-cycle validation

• After repairs, perform a practical drive cycle (city and highway) to verify the voltage remains within spec under normal operating conditions and that no additional charging/voltage-related codes reappear.

RELATED CODES

• P0560: System Voltage Malfunction (voltage out of acceptable range in a malfunctioning way)
• P0563: System Voltage Too High (less common, but sometimes seen in connection with charging system faults)

Note: Related codes typically point to charging system or electrical power supply concerns and can provide context for diagnosing P0562. Colorful variations in codes can occur depending on vehicle state, battery condition, and electrical faults.

REPAIR OPTIONS AND COSTS (2025 prices)

Prices vary by region, shop rate, and whether OEM or aftermarket parts are used. The ranges below are typical for the United States and current market trends in 2025.

• Battery replacement (12V auxiliary battery, standard lead-acid or AGM as per OEM spec):

  • Parts: roughly $100–$250
  • Labor: about $40–$120
  • Total estimate: $140–$370

• Alternator replacement or repair (charging system repair):

  • Parts: roughly $180–$500 (new OEM or remanufactured)
  • Labor: about $150–$350
  • Total estimate: $330–$850

• PCM (ECM/ECU) power supply circuit repair or replacement

  • Parts: typically $600–$1200 for the PCM power-supply related components if only a circuit repair is needed; full PCM replacement is rarer and more expensive
  • Labor: $300–$800
  • Total estimate: $900–$2000+ (highly dependent on whether PCM replacement is needed)

• Wiring harness or fusible link repair

  • Parts: $20–$200 (depending on extent)
  • Labor: $100–$500
  • Total estimate: $120–$700

• Ground strap or grounding point repair

  • Parts: $5–$40
  • Labor: $50–$150
  • Total estimate: $55–$190

• Fuses/fusible links replacement

  • Parts: $5–$30
  • Labor: minimal if located easily
  • Total estimate: $10–$60

• Parasitic draw diagnosis (if needed)

  • Labor: $100–$300 (depending on complexity)

Keep in mind: If multiple components require replacement due to long-standing voltage issues, total repair costs can be higher. Always get a detailed diagnostic report and a written estimate before proceeding with major repairs.

DIY vs PROFESSIONAL

• DIY-appropriate steps:

  • Testing battery voltage (resting and engine-running) with a multimeter
  • Cleaning and tightening battery terminals
  • Inspecting visible wiring and connectors for corrosion or obvious damage
  • Checking fuses and main electrical connections
  • Basic parasitic draw test with a multimeter ammeter (if you’re comfortable and safe)

• DIY-advise caution:

  • Working around the charging system involves high current and potential electrical hazards; incorrect repairs can cause further damage or fire risk.
  • Replacing an alternator or PCM power-supply components may require special tools and software/reflashing.
  • If your vehicle has a complex electrical network (common in newer Subarus with EyeSight, CAN bus networks, and multiple control modules), professional diagnosis is often faster and more reliable.

• Professional advantages:

  • Accurate testing of alternator under load, can perform professional parasitic draw tests, and verify PCM power rails with proper equipment.
  • Properly diagnosing and repairing wiring harness concerns and fusible link issues.
  • Access to OEM documentation, wiring diagrams, and software updates.

PREVENTION

• Maintain a healthy 12V battery:

  • Regularly check battery health and replace every 3–5 years as needed.
  • Keep battery terminals clean and tight; apply dielectric grease to posts if recommended.

• Keep charging system healthy:

  • Have the alternator tested during regular servicing, especially if the battery is aging or if you notice lights dimming or electrical accessories behaving strangely.
  • Avoid prolonged short trips that don’t give the alternator time to recharge the battery.

• Protect electrical wiring:

  • Inspect visible wiring for wear or chafing, especially around the battery, alternator, and any aftermarket accessories.
  • Repair damaged insulation to prevent shorts and electrical noise that can trigger fault codes.

• Minimize parasitic drains:

  • Turn off unnecessary electrical devices when the vehicle is off.
  • If you install aftermarket devices, ensure proper installation and fusing to avoid excessive draw.

• Routine checks after service:

  • After any electrical work, verify voltage ranges and clear any codes, then perform a test drive to confirm the issue is resolved.

Final notes

• The above guide is based on general OBD-II and electrical diagnostic practices for the Subaru Impreza platform and uses the data provided. If you have an active code P0562, prioritize verifying the health of the battery and charging system first, since low voltage is most commonly caused by battery or alternator issues. If the diagnosis becomes complicated or the vehicle exhibits drivability concerns, consult a qualified technician who can perform in-depth electrical testing and confirm any PCM-related concerns.