This procedure addresses replacement of the crankshaft position sensor on a 2023 Chevrolet Bolt EUV, which is an electric vehicle without a traditional crankshaft. This repair likely involves accessing a motor position sensor or resolver that provides rotor position feedback to the motor control unit.

Warnings

Tools required

Parts

• Motor position sensor/resolver × 1 — Use OEM specification
• Sensor O-ring or gasket × 1 — Use OEM specification
• Drive unit cover gasket × 1 — Use OEM specification
• Electrical connector seal × 1 — Use OEM specification

Fluids

• ACDelco Dexron VI ATF — 2 qt

Preparation

1. Ensure vehicle is on level ground and apply parking brake
2. Verify battery is fully charged to allow proper vehicle shutdown procedures
3. Turn off vehicle and remove key fob from cabin
4. Wear appropriate high voltage personal protective equipment including insulated gloves and safety glasses
5. Document any diagnostic trouble codes present before beginning work
6. Allow drive unit to cool to ambient temperature if vehicle was recently operated
7. Raise and support vehicle on lift or jack stands at manufacturer-specified lift points
8. Remove front driver side wheel for access to underbody components

Procedure

1. 1

   De-energize high voltage system
   Locate the high voltage service disconnect under the rear seat. Remove rear seat cushion by releasing clips. Remove orange high voltage disconnect cover. Using the high voltage disconnect tool, rotate the service plug counterclockwise and remove completely. Store the service plug in a secure location away from the vehicle. Install lockout/tagout device. Wait minimum 5 minutes for capacitor discharge.
   ⚠️Do not proceed until 5 minutes have elapsed and high voltage disconnect is confirmed removed and secured away from vehicle.
2. 2

   Verify high voltage de-energization
   Using a CAT III or higher rated digital multimeter, verify zero voltage at the high voltage battery terminals and at the motor power cables (orange cables). Voltage should read 0V DC. If any voltage is detected, do not proceed and investigate the cause. Document voltage readings.
   ⚠️If voltage is present after 5 minute wait and disconnect removal, the high voltage system has not properly de-energized. Do not continue.
3. 3

   Disconnect 12V battery
   Locate the 12V battery in the front compartment. Using a 10mm wrench, disconnect the negative battery cable first, then the positive cable. Secure cables away from battery posts. Wait 2 minutes for all vehicle modules to power down completely.
   ⚠Disconnecting 12V battery will erase radio presets and may require reinitialization of some vehicle systems after repair.
4. 4

   Remove drive unit splash shields and access covers
   From under the vehicle, remove the front splash shield fasteners and lower the shield. Remove any additional underbody covers that obstruct access to the drive unit. Locate and remove the drive unit lower cover bolts. Carefully lower the cover and allow transmission fluid to drain into a suitable container. Expect approximately 2 quarts of fluid loss.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
5. 5

   Disconnect motor electrical connectors
   Locate the motor position sensor electrical connector on the drive unit housing. Depress the connector lock tab and carefully separate the connector. Inspect connector for corrosion or damage. If connector bolts are present, remove them first. Position connector away from work area and protect from contamination.
   Torque spec

   Electrical Connector Bolts7 Nm (5 lb-ft)
6. 6

   Remove drive unit mounting bolts (partial support)
   Install motor support fixture to support the drive unit weight. Remove the upper drive unit mounting bolts to allow slight repositioning of the drive unit for sensor access. Do not fully remove the drive unit. Only loosen enough to gain access to the sensor mounting area. Support the drive unit securely with the support fixture.
   ⚠Drive unit weighs approximately 150 lbs. Ensure support fixture is properly rated and secured before removing mounting bolts.
   Torque spec

   Mounting Bolts47 Nm (35 lb-ft)
7. 7

   Remove sensor access cover and gasket
   Locate the sensor access cover on the motor housing (typically on the transmission end of the motor). Remove the gasket surface bolts in a crisscross pattern to prevent warping. Carefully pry the cover away from the housing using a non-conductive pry bar if needed. Remove and discard the old gasket. Clean all mating surfaces thoroughly with gasket scraper and degreaser, ensuring no debris enters the motor housing.
   ⚠Do not allow any dirt, debris, or cleaning materials to enter the motor housing as this will contaminate internal components and cause failure.
   Torque spec

   Gasket Surface Bolts20 Nm (15 lb-ft)
8. 8

   Remove motor position sensor
   Locate the motor position sensor/resolver mounted to the motor housing. Remove the sensor mounting bolts carefully, keeping track of any washers or spacers. Gently pull the sensor straight out from the housing to avoid damaging the sensor element or the rotor. Inspect the sensor rotor on the motor shaft for damage or debris. If sensor is seized, carefully work it loose without prying against the housing.
   ⚠The sensor contains precision components. Do not drop, strike, or contaminate the sensing element.
   Torque spec

   Mounting Bolts47 Nm (35 lb-ft)
9. 9

   Inspect and prepare for installation
   Inspect the sensor mounting bore in the housing for damage, debris, or corrosion. Clean thoroughly with lint-free cloth and appropriate solvent. Inspect the new sensor for correct part number and any shipping damage. Remove any protective caps from the new sensor. Install new O-ring or gasket on the sensor body, lightly lubricating with clean transmission fluid. Verify the sensor rotor on the motor shaft is clean and properly positioned.
   ℹ️Some sensors require specific orientation or air gap settings. Consult service information for this specific sensor configuration.
10. 10

    Install new motor position sensor
    Carefully align the new sensor with the mounting bore and rotor. Insert the sensor straight into the housing, ensuring it seats fully without binding. Install sensor mounting bolts with washers if equipped. Torque bolts to specification in a crisscross pattern to ensure even seating. Verify the sensor is fully seated and flush with the mounting surface.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)
11. 11

    Install sensor access cover with new gasket
    Install new gasket on the sensor access cover or housing as applicable. Ensure gasket is properly positioned and not pinched. Position the cover onto the housing, aligning all bolt holes. Install gasket surface bolts finger-tight first, then torque in a crisscross pattern to specification to ensure even gasket compression and proper seal.
    Torque spec

    Gasket Surface Bolts20 Nm (15 lb-ft)
12. 12

    Reinstall drive unit mounting and reconnect electrical
    Using the support fixture, reposition the drive unit to its normal mounted position. Install and torque the drive unit mounting bolts to specification. Remove support fixture. Reconnect the motor position sensor electrical connector, ensuring it clicks fully into place. If connector bolts are present, install and torque to specification. Verify connector lock is engaged.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)

    Electrical Connector Bolts7 Nm (5 lb-ft)
13. 13

    Reinstall drive unit covers and refill transmission fluid
    Install new drive unit lower cover gasket if equipped. Position the lower cover and install cover bolts, torquing to specification. Locate the transmission fill plug on the drive unit. Remove fill plug and add approximately 2 quarts of ACDelco Dexron VI ATF or until fluid reaches the bottom of the fill hole with vehicle level. Reinstall fill plug. Reinstall all underbody splash shields and covers.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
14. 14

    Reconnect 12V battery and restore high voltage
    Reconnect the 12V battery positive cable first, then negative cable. Torque battery cable nuts to specification. Verify all tools and materials are clear of the high voltage service disconnect area. Remove lockout/tagout device. Reinstall the high voltage service disconnect plug by rotating clockwise until fully seated. Install the orange disconnect cover and rear seat cushion.
    ⚠️Ensure high voltage service plug is fully seated and locked before attempting to power on vehicle.
15. 15

    Initialize and test vehicle systems
    Reinstall driver side wheel and torque lug nuts to specification. Lower vehicle to ground. With brake pedal depressed, press the power button to start the vehicle. Observe the instrument cluster for warning lights. Use a diagnostic scan tool to verify motor position sensor is communicating properly and no DTCs are present. Perform a controlled test drive to verify normal propulsion operation, smooth acceleration, and no abnormal noises or vibrations.
    ⚠If warning lights remain illuminated or new DTCs are present, do not drive vehicle. Investigate and resolve issues before releasing to customer.

Reassembly

1. Reinstall all components in reverse order of removal
2. Ensure all electrical connectors are fully seated and locked
3. Verify all torque specifications are met, particularly critical gasket and mounting bolts
4. Confirm transmission fluid level is correct with vehicle level
5. Double-check that high voltage service disconnect is properly reinstalled and secured

Verification

• Scan for diagnostic trouble codes using appropriate scan tool - there should be no motor or sensor related codes
• Verify motor position sensor signal is present in scan tool live data
• Test drive vehicle and verify smooth acceleration with no hesitation or loss of power
• Verify no unusual noises from drive unit during acceleration and deceleration
• Check for any fluid leaks from sensor area and drive unit covers after test drive
• Verify all warning lights extinguish after vehicle initialization
• Confirm regenerative braking functions normally
• Document repair with final odometer reading and any notes for customer

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