The VIA eRev van is a factory-new, electrified, extended range vehicle. This course is designed to familiarize technicians with the van's components and systems, as well as provide an overview of
​important van safety information. 

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  • ​Charging system
  • Export power panel
  • Traction, or drive system
  • Power electronics cooling system
  • Generator and traction motor cooling system
  • HVAC system
  • Low voltage fuse center
  • Hybrid control unit, or HCU
  • Power steering pump
  • Driver interface
  • Fluid locations and checking procedures
  • Maintenance instructions 
  • High voltage safety overview
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​The EVSE is located on the left front fender.
Level 1 (120 volt) or level 2 (240 volt) EVSEs can be used.
  • This A/C voltage is sent to the Bi-directional charger.
  • The power electronics pump is located behind the left side of the front bumper. It will run during the external charging process. Additional unexpected clicking sounds may be caused by the electrical devices used while charging.
  • EVSE port indicator lamp will illuminate under these conditions:
  1. Blinking green light: Charge in progress
  2. Solid green light: Charge complete
  3. Solid red light indicates the charging unit is not wired correctly or that the charging unit is unable to communicate with the vehicle.
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The onboard evaporative emission (EVAP) control system limits harmful fuel vapors from escaping into the atmosphere. During periods where the vehicle is not driven or operated primarily in battery/electric mode fuel vapors accumulate and are stored in the EVAP canister until the engine is able to use them. After not using or driving the vehicle without sufficient engine operation for a long enough time period, the EVAP canister will be almost saturated with vapors and the vehicle control system must run the engine to purge and prevent overflow into the atmosphere. 

Purge operation will be requested after 4.7 days without sufficient engine operation and activated once the battery is below 80% charge. If the drive starts with the battery still above this level, the vehicle will operate in electric mode until the battery depletes to 80%, at which point purge operation will begin. Purge operation is similar to normal charge sustaining operation except for possible elevated battery charge level and a maximum power of system will reduce the 4.7-day period to account for additional vapors pushed into the canister. At most, if the tank is refilled completely from empty, purge operation will be requested as a much as 15 hours before normal. 

EVAP canister purge is completed during a drive if the engine runs at sufficient load for at least 15 minutes. This 15 minutes may be achieved over any number of drives within 2 days. If 15 minutes of sufficient engine load is not achieved within the 2-day period, the timer will reset and 15 minutes will again be required. Sufficient engine load generally occurs when driving at speeds greater than 50 mph (i.e. highway driving). 

If the battery is charged during the period when EVAP canister purge is required (after 4.7 days without sufficient engine operation ), the vehicle control system will not allow it to charge above 80%. This ensures the engine will immediately be able to run and consume all the vapors at the beginning of the drive. 

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  • Located at the rear of the internal combustion engine.
  • Replaces the standard automatic transmission
  • Controlled by the generator inverter.
  • Uses a dry sump lubrication system with DEXRON® VI automatic transmission fluid.
  • Engine driven
  • Supplies current to the high voltage battery to maintain a 20% state of charge.
  • Powers the traction motor or export power panel, when the charge level falls below 20%.
  • The generator is also be used as a starter for the internal combustion engine.
  • The generator will either use or produce A/C power.
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The high voltage battery is part of the charging system and is located between the engine mounted high voltage generator and the H-frame.

The high voltage battery weighs approximately 800 pounds. Power is provided by a lithium ion high voltage battery pack with up to 400 volts available.

The high voltage battery houses:
  • Battery Control Module (or BCM)
  • Current Sense Module (or CSM)

The high voltage battery supplies high voltage to:
  • The DC to DC converter
  • Traction Inverter
  • Generator Inverter
  • Bi-directional charger
  • AC Compressor
  • Cabin Heater

There are no serviceable components inside the battery pack; only replaceable system fuses within the fuse center.
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​1. The Current Sense Module (or CSM) is a sensor that communicates on the CAN bus. It is measurement-triggered for coordinated measurement with other battery modules. It also performs isolation monitoring between high and low voltage systems.

2. The Electrical Distribution Module (or EDM) provides a high voltage relayed connection between the battery and the vehicle. There are two types of contactors in the battery: a pre-charge contactor and a main contactor. The pre-charge contactor applies a lower voltage to the system before the main contactors close to reduce the high voltage arcing.

3.  The Manual Service Disconnect (or MSD) disconnects the High Voltage Intercept Loop (or HVIL) so the pack will not receive a 12 volt signal and mechanically disconnects the high voltage system.
4. The Battery Control Module (or BCM) powers the low voltage electronic systems within the pack and coordinates battery state measurements, charge and discharge calculations, over current determination, over or under voltage determination, and cell state of charge balancing.
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5. Battery Pack Cell Modules are also included in the high voltage battery components.
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6. The High Voltage Battery System Fuse Center is also included in the high voltage battery components.

Please Note: There are no serviceable components inside the battery pack; only replaceable system fuses within the fuse center. 
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The fuse center for the high voltage system is located on the underside of the HV battery.

This contains the following fuses:

• DC/DC converter fuse (25 amp)
• Cabin heater fuse (25 amp)
• A/C compressor fuse (25 amp)
• Bi-directional charger fuse (80 amp)


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WARNING: High voltage precautions should be taken before servicing the fuses.
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Located at the front of the vehicle, behind the front bumper on the right side. The front bumper must be removed to access this pump.

The generator oil pump DEXRON® VI pumps automatic transmission fluid through the generator cooling system.
  • The system includes a pressure sensor, radiator, reservoir and filter.

The generator oil pump is controlled by the Hybrid Control Unit (HCU).
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  • Mounted to the vehicle, next to the right inner frame rail, above the traction motor inverter.

  • The H-frame must be removed to service this component.
 
  • Converts A/C voltage to D/C voltage to charge the High Voltage battery.
 
  • Allows the output from the generator speed to be controlled based on demand.
 
  • The generator output supplies power to maintain the high voltage battery at a 20% state of charge and operates the traction motor once the high voltage battery reaches a 20% state of charge.
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  • The generator inverter is liquid cooled by a mixture of 50% DEX-COOL and deionized water.
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Located at the center of the vehicle, on the right inner frame area of the H-frame. It reduces the voltage of the high voltage battery to system voltage which will:
  • Recharge the vehicle’s 12 volt battery.
  • Provide voltage to operate the vehicle while driving.

The input voltage ranges from 240 to 430 volts, with a nominal 350 volts.

The output voltage ranges from 9 to 16 volts with a nominal voltage of 14.4 volts.

​The DC to DC converter is liquid-cooled uses a mixture of 50% DEX-COOL and deionized water.
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1. DC/DC converter control connector (DC voltage)
2. Low voltage input (DC voltage) from HV battery
3. High voltage input (DC voltage) from HV battery
4. Power electronics coolant outlet hose
5. Power electronics coolant inlet hose
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Located under the rear of the vehicle, in front of the muffler.

Performs two functions:
  • Converts either 120 or 240 volt A/C power into D/C current to charge the high voltage battery using an EVSE to supply the A/C current safely.
 
  • Converts high voltage D/C current into either 240 volt A/C current to supply the export power panel with usable A/C power.


Operates at 240 to 430 volts D/C and 120 to 240 volts A/C at 60 hertz. The bi-directional charger powers up to 14.4 kilowatts in either direction.

The bi-directional is liquid cooled with a mixture of 50% DEX-COOL and deionized water.
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1. HV connection goes to the HV battery (DC high voltage)
2. HV connection goes to the EVSE charging connection (AC voltage)
3. Export power panel connection (AC voltage)
4. Export power panel connection (DC voltage)
5. Bi-directional charger control connector (DC voltage)
6. Power electronics coolant inlet hose
7. Power electronics coolant outlet hose 
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The export power panel is located on either the right or left rear side of the quarter panel.

It contains two 30 amp, 240 volt A/C outlets  (3 prong and one 4 prong)

​An adapter may be used to provide two 120V outlets.

There is 14.4 kilowatts of total available power between both connectors.

Export power may be used until the high voltage battery reaches a 20% state of charge.
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  • At that point an alarm will sound and the outlet will shut down.
  • In order to continue, insert the vehicle key into the ignition and turn to the run position.
  • The engine will start and drive the generator. Export power will then resume.
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The traction (or drive) system is made up of the following components:

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Located at the front of the vehicle, behind the front bumper on the left side. The front bumper must be removed to access this pump.

Pumps DEXRON® VI pumps automatic transmission fluid through the traction motor cooling system.
  • System includes a pressure sensor, radiator, reservoir and filter.


Controlled by the hybrid control unit (or HCU).
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Located on the H-frame and is bolted to the gearbox.

The H-frame must be removed to service the traction motor.

Controlled by the traction inverter.

Uses a dry sump lubrication system with DEXRON® VI automatic transmission fluid.

The traction motor will either use or produce A/C current.
  • It uses power during driver modes.
  • Produces power during regenerative braking.
   Gearbox                         H-frame                   Traction Motor
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  • Located on the left outer frame rail, in front of the left rear leaf spring.
  • The gear selector on the column is actually a directional and park selection device.
  • P or Park position uses an electrically operated device that locks up the drivetrain to prevent movement while parked.
  • R or Reverse selection will cause the vehicle to back up.
  • N or Neutral selection will remove power flow to the electric drive.
  • D or Drive selection is the normal operating position.
  • 2 This position operates the same as D or Drive. 
  • 1 This posistion is a power assist function. The APU is enabled and provides additional power during low battery temperature/state of charge, large hill climb or other conditions where the power from the high voltage battery is insufficient to operate the vehicle at the requested level.
  • Drive (D) is the preferred position for normal operation. 

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  • Located on the H-frame between the traction motor and the drive shaft.
  • The H-frame must be moved to service the gearbox
  • 2.68 to 1 reduction.​
  • Uses 1.4 liters of DEXRON® VI 
               Gearbox        Traction Inverter         Traction Motor 
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  • The gearbox fluid level should be checked at every engine oil change interval. 

  • The fluid level should be checked with the vehicle parked on a level surface.
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  • With the fill plug removed, the fluid level should be even with the bottom of the case fill plug opening.
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Located on the back of the gearbox.
  • Can be serviced with the H-frame in place.
  • The ePark module powers up with input from the ignition switch and the position of the PRNDL.
  • Usually ready to initiate the first shift request within 2 seconds.
  • Used in conjunction with the parking brake.

The ePark module has three conditions:

• Park
• Unpark
• And no action








ePark module 


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           Gearbox
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  • Located on the H-frame below the generator inverter, in front of the DC to DC converter.
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  • It converts DC power from the high voltage battery to regulated 3-phase A/C current.

  • It controls high voltage to the traction motor during acceleration.

  • Regenerative braking enables the traction motor to operate as a generator when coasting or braking. This provides energy to recharge the high voltage battery.

  • The traction inverter is liquid-cooled uses a mixture of 50% DEX-COOL and deionized water.
DC/DC converter           H-frame              Traction Inverter
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Power electronics cooling system contains the following components:

• Cooling fan
• Radiator
• Cooling pump
• Reservoir

Cools the following components:

• Generator and traction inverters
• High voltage battery
• DC to DC converter
• Bi-directional charger

It uses a mixture of 50% DEX-COOL and deionized water.

The total capacity of this system is approximately 2 gallons.

The system is full when the coolant mixture is 2 inches below the top of the reservoir.
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Note: The pump is located behind the left side of the front bumper. It is normal for the pump to be heard running during plug in charging.
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Note: Blue lines to the HV battery are for a vehicle option that may not be present on every vehicle.
A.Radiator
B.Reservoir
C.Coolant Pump
D.HV Battery
​E. Generator Inverter
F. Traction Inverter
G. DC/DC Converter
H. Bi-directional Charger
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The Generator and Traction Motor Cooling Systems share the same fluid reservoir.

Contain the following components:
  • Cooling fan
  • Radiator
  • Cooling Pumps (one pump is for the generator, the other is for the traction motor)
  • Reservoir
  • Filter
  • Pressure sensor
 
  • DEXRON® VI Automatic Transmission Fluid is pumped through the system.
  • The total capacity of this system is about 10.5 quarts.

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A.Generator Oil Pump
B.Traction Motor Oil Pump
C.Generator Cooling System Radiator
D.Generator/Traction Motor Cooling System Radiator
E.Traction Motor Oil Filter
​F. Generator Oil Filter
G. Generator/Traction Motor System Fluid Reservoir
H. High Voltage Generator
I. Traction Motor

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The HVAC system is similar to the factory system except:

A high voltage A/C compressor has been added (close to the same location as the engine mounted compressor). It serves the same purpose as the factory belt driven compressor.

A high voltage cabin heater has been added (under the engine, on the crossmember). It heats the coolant for the cabin heater in the same manner as the internal combustion engine (ICE) does when it’s running. The heater has an HV side (heating units) and a low voltage control module side. A coolant temperature sensor is located in the outlet side of the heater and is used to monitor the coolant output temperature of the heater. Amperage to the heater is controlled to vary the temperature output.
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A vacuum pump has been added (located behind the grille under the right headlight). The electric vacuum pump supplies vacuum to the HVAC module to support the function of the HVAC doors.






​A variable speed coolant pump has been added (next to the A/C compressor, above the ICE crossmember). The coolant pump pumps coolant into the HVAC module in the same manner as the engine mounted water pump. The coolant pump varies the flow through the heater to also control the temperature of the coolant


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  • The low voltage fuse center is located under the left side of the hood, next to the master cylinder reservoir.
  • The fuse locations are inscribed on the fuse center cover.

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  • Hybrid control unit (or HCU) is similar to a body control module (or BCM).

  • It uses inputs and signals from the VIA system and the GM factory system to manage total vehicle operation.
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  • ​Located next to the 12 volt battery.

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  • An electric power steering pump is used in place of the belt driven pump.

  • The pump is located on the crossmember in front of the engine, next to the steering gearbox.

  • The pump is powered by 12 volts.
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  • Requires GM factory Power Steering Fluid.

  • The fluid level is checked in the same manner as the factory belt driven system.
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  • The generator kW gauge shows the output of the engine mounted generator.
  • Shows high voltage output during export power mode.
  • The output will vary based on demand.
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  • The malfunction indicator lamp (or MIL) illuminates amber when the vehicle is placed in ON/RUN, as a check to confirm functionality.
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  • If the MIL comes on for more than 15 seconds on startup or while the engine is running, this indicates that the OBD II system has detected a problem.

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  • While accelerating or driving, the blue scale will show power usage.
  • When coasting or braking, the green scale will show regenerative power recovery.
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  • The Hybrid System Lamp (HSL) illuminates when the Battery is overheating, has overheated or when the battery experiences an internal fault that prevents it from enabling HV system.
  • It only comes on in extreme conditions.
  • The vehicle performance may be automatically reduced to protect itself.

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  • The Battery Percent Gauge indicates the remaining charge in the high voltage battery.
  • When the EVSE is connected and charging is complete, the gauge will indicate 100% to reflect a fully-charged high voltage battery.
  • As the vehicle is driven in battery electric mode, the percentage will reduce until the engine starts. At that point the vehicle will be powered by the engine mounted generator.
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  • The “Ready to Drive” indicator will illuminate green when the vehicle is ready to drive.
  • It is used while in battery electric startup mode to indicate all necessary systems are functioning and the vehicle is ready to drive.
  • The indicator will stay on as long as the vehicle is active.

Note: Wait for the “Ready to Drive” indicator to illuminate before driving.
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Note: The Generator and Traction Motor fluid should be checked weekly and when the fluid is cold.

1. Flip the handle up, pull out the dipstick, and wipe it with a clean rag or paper towel.
2. Push it back in all the way, wait three seconds, and pull it back out again
3. Check both sides of the dipstick, and read the lower level. The fluid level must be between the 2 indicators on the dipstick. Be sure to keep the dipstick pointed down to get an accurate reading.
4. If the fluid level is in the acceptable range, push the dipstick back in all the way, then flip the handle down to lock the dipstick in place.
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The power electronics fluid level should be checked weekly. 

Warning: Steam and scalding liquids from a hot cooling system can blow out and cause serious burns. Never turn the surge tank pressure cap, when the cooling system is hot. Wait for the cooling system and reservoir tank pressure cap to cool.
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  1. Remove the surge tank pressure cap when the cooling system is no longer pressurized.
  2. Push down the pressure cap as you turn it.
  3. Remove the pressure cap.
  4. Fill the reservoir with the proper mixture of 50% DEX-COOL and deionized water, 2 inches below the top of the reservoir.
  5. Replace the pressure cap.

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Please review the maintenance chart for recommended service intervals

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  • High voltage is normally considered to be any voltage over 50 volts either AC or DC. The high voltage battery in a VIA extended range vehicle is approximately 400 volts, so all safety precautions must be taken when servicing the vehicle.
  • When the EVSE is connected, or when export power is in use, either 120 volts or 240 volts will be present on certain circuits.
  • A VIA battery that shows a depleted state of charge, still carries at least a 20% charge and has the capacity to produce an electrical shock.
  • Be aware of high voltage safety warning labels on components.
  • High voltage circuits will be identified by orange cables or conduit, but all circuits should be treated as potentially dangerous. Never cut or open high voltage components and orange cables. Failure to follow this warning could result in property damage, personal injury, or death.
  • Heavy gauge wire is not always required for high voltage flow. ALL orange wiring should be assumed to be carrying high voltage.
  • A 12 volt signal sent to the Battery Control Module (or BCM) closes contactors allowing voltage to flow to the high voltage system. Always follow the “High Voltage Disabling/Enabling” procedure before servicing the vehicle.

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