GM Service Manual Online
For 1990-2009 cars only

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition ON, Transfer Case in 2WD and Brake released

4WD Status

4WAL 3 Sensor

Two wheel drive/Four wheel drive

Two wheel drive

ABS Lamp Command

4WAL 3 Sensor

On/Off

Off

ABS Pump Motor

4WAL 3 Sensor

On/Off

Off

ABS Relay Command

4WAL 3 Sensor

On/Off

On

ABS Stop State

4WAL 3 Sensor

On/Off

Off

Brake Switch Status

4WAL 3 Sensor

On/Off

Off

Brake Warning Lamp Command

4WAL 3 Sensor

On/Off

Off

Diff. Pressure/Fluid Level

4WAL 3 Sensor

Ok/Low

Ok

DRP Active

4WAL 3 Sensor

Yes/No

No

Left Front Wheel Speed

4WAL 3 Sensor

km/h or mph

5 km/h/3 mph

LF Dump Valve Command

4WAL 3 Sensor

On/Off

Off

LF Dump Valve Feedback

4WAL 3 Sensor

On/Off

Off

LF ISO Valve Command

4WAL 3 Sensor

On/Off

Off

LF ISO Valve Feedback

4WAL 3 Sensor

On/Off

Off

Rear Dump Valve Command

4WAL 3 Sensor

On/Off

Off

Rear Dump Valve Feedback

4WAL 3 Sensor

On/Off

Off

Rear ISO Valve Command

4WAL 3 Sensor

On/Off

Off

Rear ISO Valve Feedback

4WAL 3 Sensor

On/Off

Off

Rear Wheel Speed

4WAL 3 Sensor

km/h or mph

5 km/h/3 mph

RF Dump Valve Command

4WAL 3 Sensor

On/Off

Off

RF Dump Valve Feedback

4WAL 3 Sensor

On/Off

Off

RF ISO Valve Command

4WAL 3 Sensor

On/Off

Off

RF ISO Valve Feedback

4WAL 3 Sensor

On/Off

Off

Right Front Wheel Speed

4WAL 3 Sensor

km/h or mph

5 km/h/3 mph