Range Optimization Service

Comprehensive diagnostic and optimization service to maximize electric range on the 2023 Chevrolet Bolt EUV, including tire pressure optimization, brake system inspection, cooling system check, and software diagnostics.

Warnings

Tools required

Parts

• Cabin air filter × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure vehicle has been driven recently to assess current range performance
3. Charge battery to 100% if possible for baseline testing
4. Place wheel chocks behind rear wheels
5. Allow vehicle to remain off for at least 5 minutes before beginning service
6. Record current odometer reading and average range displayed on instrument cluster

Procedure

1. 1

   Connect diagnostic tool and perform initial scan
   Connect OBD-II scan tool to diagnostic port located below steering column. Power on vehicle to accessory mode without putting into Ready mode. Retrieve any stored diagnostic trouble codes (DTCs) related to battery management, motor controller, charging system, or HVAC. Record battery state of health (SOH) and current degradation metrics. Check for any software updates available for propulsion or energy management systems.
2. 2

   Inspect and optimize tire pressures
   Check tire pressures on all four tires when cold. Compare readings to the vehicle placard specification (typically 39 PSI front and rear for Bolt EUV). Inflate or deflate tires to exact specification. Underinflated tires are a primary cause of reduced range. Inspect tires for uneven wear patterns that may indicate alignment issues affecting efficiency. Record pressure adjustments made.
3. 3

   Inspect brake system for drag
   Raise vehicle if possible and rotate each wheel by hand to check for brake drag or binding. Listen for unusual noises or feel for resistance that could indicate partially engaged brake calipers. With vehicle on ground, take short test drive and use infrared thermometer to check brake rotor temperatures at all four corners after light driving. Significant temperature differences may indicate dragging brakes reducing range. Inspect brake pad thickness and ensure regenerative braking system is functioning properly.
4. 4

   Inspect cabin air filter and HVAC efficiency
   Locate cabin air filter behind glove box assembly. Remove glove box by releasing side stops. Remove and inspect cabin air filter for excessive dirt, debris, or restriction. A clogged filter forces HVAC system to work harder, consuming more battery energy. Replace filter if visibly dirty or restricted. Ensure HVAC intake is clear of debris. Test HVAC fan operation at all speeds to verify proper function.
5. 5

   Check electric drive unit fluid level and condition
   Locate drive unit fluid level check plug on driver side of transaxle assembly. With vehicle level and at operating temperature, carefully remove check plug. Fluid should be at bottom of check plug hole. Verify fluid is clean pink/red color (Dexron VI). Check for metal particles or burnt odor indicating internal wear that could reduce efficiency. Add fluid only if low. Do not overfill as this creates parasitic drag.
6. 6

   Inspect battery thermal management system
   Verify battery coolant level in reservoir is within MIN/MAX marks. Coolant should be orange DEX-COOL and appear clean without contamination. Check coolant freeze point protection using hydrometer or refractometer; should protect to at least -34°F. Proper thermal management is critical for range optimization. Inspect coolant hoses for leaks or damage. Check battery thermal system operation by monitoring coolant temperature with diagnostic tool during short test drive.
7. 7

   Verify charging system efficiency
   Inspect charge port door for proper operation and weather seal integrity. Check charge port pins for corrosion, damage, or debris that could affect charging efficiency. Verify onboard charger and DC fast charge systems show no faults in diagnostic data. Poor charging efficiency or battery degradation will affect available range. Review charging history data for patterns indicating charging system issues.
8. 8

   Inspect underbody aerodynamic components
   Raise vehicle if possible and inspect underbody aerodynamic panels and shields for damage or missing fasteners. The Bolt EUV uses underbody panels to reduce drag and improve range. Ensure all panels are securely attached and not hanging down. Check for any aftermarket accessories like trailer hitches or bike racks that may be creating aerodynamic drag when not in use.
9. 9

   Review and optimize driver settings
   Access vehicle settings through infotainment system. Verify One-Pedal Driving mode is enabled if customer desires maximum regenerative braking efficiency. Review climate control settings and recommend use of heated seats/steering wheel instead of cabin heat when possible to conserve range. Check that tire pressure monitoring system (TPMS) is functioning correctly. Verify energy usage displays are configured to help driver monitor consumption.
10. 10

    Perform battery conditioning and range test
    If battery SOH shows degradation or capacity loss, perform a full charge/discharge cycle if time permits to recalibrate battery management system. Drive vehicle for 5-10 miles in mixed conditions while monitoring instantaneous energy consumption (mi/kWh). Compare actual consumption to EPA estimates (approximately 3.5-4.0 mi/kWh). Reset trip computer and average range calculations. Document baseline range performance for customer comparison.

Reassembly

1. Reinstall cabin air filter access cover and glove box assembly
2. Ensure all filler caps and check plugs are properly secured
3. Lower vehicle if raised and remove wheel chocks
4. Clear any diagnostic tool connections

Verification

• Verify no new DTCs are present after service completion
• Confirm all tire pressures are at specification and TPMS shows no warnings
• Test drive vehicle and verify regenerative braking operates smoothly with no pulling or unusual brake behavior
• Verify range estimate on instrument cluster displays expected value based on current charge level
• Confirm HVAC system operates efficiently at all fan speeds
• Provide customer with before/after range optimization report including any findings and recommendations
• Educate customer on range-maximizing driving techniques including one-pedal driving, preconditioning while plugged in, and efficient climate control use

Related trouble codes on this vehicle

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