Bus Connections
The primary OBD-II connector on the driver's side hosts the following buses:
| Data Pins | Speed | Connected To | |
|---|---|---|---|
| Low-speed GMLAN | 1 | 33.3K | Coolant heater, HVAC, instrument cluster, keyless entry, seat heaters, onstar, radio, seat sensors, parking sensors |
| Primary High speed GMLAN | 6(+) 14(-) | 500K | onstar, parking brake, fuel pump, brakes, both drive motors, Engine control, HV drive electronics, AC compressor |
| Chassis high-speed GMLAN | 12(+) 13(-) | 500K | brakes, both drive motors, Engine control, HV drive electronics, accelerometer, steering |
Additionally, the second connector, located on the passenger's side, hosts the following:
| Data pins | Speed | Connected To | |
|---|---|---|---|
| Powertrain high-speed GMLAN | 12(+) 13(-) | 500K | Both drive motors, Engine control, HV drive electronics, 12V inverter |
| High-voltage energy management high-speed GMLAN | 3(+) 11(-) | 500K | HV battery charger, HV battery electronics |
Finally, a 10.417 Kbit/s LIN bus is used to connect together the Body Control Module, window motors and switches, and the wiper motor. Another LIN bus appears to connect the HVAC controls back to the HVAC system.
Also see this page.
Volt Data
The volt is based on the GM Global A platform, but has some special modules installed and PIDs available specifically for the battery, charger, and motor electronics. These are documented in part below.
Live Data (Module-to-Module) from Primary High speed GMLAN
0C9 Byte 5 Accelerator 0 (0%) to 254 (100%)
0F1 Byte 2 Brake 0 (0%) to Unknown (254?) Typical pressure on brake pedal generates about 30.
120 Bytes 1-4 Odometer 1/64 km: e.g. 1234320 (0x0012D590) represents 19286.25 km or 11983.92 mi
135 Byte 1 Drive Position 0=Park, 1=Neutral, 2=Drive/L, 3=Reverse
1A1 Byte 8 Accelerator 0 (0%) to 254 (100%)
1C3 Byte 8 Accelerator 0 (0%) to 254 (100%)
1EF Bytes 3-4 Gas Engine RPM RPM
1F5 Byte 4 Shift Position PRNDL 1=Park, 2=Reverse, N=Neutral, D=Drive, L=Low
206 Bytes 1-2 Battery SOC .250kWh Units possibly .244kWh
32A Bytes 1-4 GPS Latitude Milliarcseconds
32A Bytes 5-8 GPS Longitude Milliarcseconds
3E9 Bytes 1-2 Speed 1/64 KPH (90KPH would be 5760 (0x1580))
5EC Byte 3 Charging Current units 0.2 A (ex. 14.2 A = 0x47)
5EC Byte 4 Charging Voltage units 2 V (ex. 222V = 0x6F)
5EC Byte 5 Outside Air Temperature in °C unit 0.5°C offset +40 (exp.: 0x60 = 8.0 °C)
5EC Byte 6 Outside Air Temperature filtered in °C unit 0.5°C offset +40
Known PIDs (over ODB-II/UDS)
request over 7E4, answer in 5EC:
Onboard charger current: 0x4369
Onboard charger voltage: 0x4368
outside temperature (filtered): 0x801F
outside temperature (raw): 0x801E
High Voltage battery Temperature: 0x434F
Power Electronics Cooling Loop temperature: 0x1C43
| Name | ShortName | Mode-PID # | Equation | Units |
|
|---|---|---|---|---|---|
| Ambient Air Temp | AAT | 22-0046 | X-40 | °C | 1 |
| Control Module Voltage | VPWR | 22-0042 | X*.001 | V | 2 |
| Engine Coolant Temp | ECT | 22-0005 | X-40 | °C | 1 |
| Intake Manifold Absolute Pressure | MAP | 22-000B | X+0 | kPa | 1 |
| Engine RPM | RPM | 22-000C | X*.25 | rpm | 2 |
| Vehicle Speed Sensor | VSS | 22-000D | X+0 | kph | 1 |
| Ignition Timing Advance for #1 Cylinder | SPARKADV | 22-000E | (X*.5)-64 | BTDC | 1 |
| Intake Air Temperature | IAT | 22-000F | X-40 | °C | 1 |
| Commanded Throttle Actuator Control | TAC | 22-004C | X*(100/255) | % | 1 |
| Hybrid/EV Battery Pack Remaining Charge | BAT_PWR | 22-005B | X*(100/255) | % | 1 |
| Fuel System Status | 22-1131 | X+0 | X+0 | ||
| AC High Side Pressure | 22-1564 | Unknown | kPa | ||
| Short Term Fuel Trim Bank 1 | na | 22-1570 | X*(100/255) | % | |
| Short Term Fuel Trim Bank 2 | na | 22-1571 | X*(100/255) | % | |
| Long Term Fuel Trim Bank 1 | na | 22-1572 | X*(100/255) | % | |
| Long Term Fuel Trim Bank 2 | na | 22-1573 | X*(100/255) | % | |
| Torque Delivered Signal | na | 22-1A2D | Unknown | NM | |
| Output Shaft Speed | na | 22-1942 | X*(1/4) or (1/8) | RPM | |
| Gear Ratio | 22-19A1 | na | Might be X*(4/256) | na | |
| Trans Fluid Temp | na | 22-1940 | X-40 | °C | |
| Transmission ISS | na | 22-1941 | Might be X*(8192/65536) | RPM |