GM Service Manual Online
For 1990-2009 cars only

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Engine Idling/Radiator Hose Hot/Closed Throttle/Park or Neutral/Closed Loop

5 Volt Reference 1

Eng 1

OK, Fault

OK

5 Volt Reference 2

Eng 1

OK, Fault

OK

12 Volt Reference

Eng 1

OK, Fault

OK

24X Crank Sensor

Eng 2, Misfire

RPM

Varies

A/C High Side Pressure

Eng 2

Volts

Varies

A/C Relay Command

Eng 1, Eng 2, Eng 3, Misfire

On, Off

OFF, unless commanded ON

AIR Fuel Ratio

Eng 2, Eng 3, EVAP, Fuel Trim

: 1

14.5-14.9

AIR Pump Relay Command

Eng 1, Fuel Trim

On, Off

Off

Air Solenoid Command

Eng 1, Fuel Trim

On, Off

Off

BARO

Eng 1, EVAP, Fuel Trim

kPa

85-103 kPa

CKP Sensor Status

Misfire

Angle, Time A, Time B

Angle

CMP Sensor

Eng 2, Misfire

RPM

Varies

CMP Sensor Signal Present

Misfire

Yes/No

Yes

Crank Request Signal

Eng 3

No, Yes

Yes

Cruise Control Active

Eng 2, Eng 3

No, Yes

No

Cruise Inhibit Signal Command

Eng 3

On, Off

On

Current Gear

Eng 1, Eng 2, Fuel Trim

1, 2, 3, 4

1

Cycles of Misfire Data

Misfire

Counts

Varies

Desired EGR Position

Eng 2

%

0

Desired Idle Speed

Eng 1, Eng 2, Eng 3, EVAP

RPM

650 RPM

ECT Sensor

ALL

°C, °F

Varies

EGR Position Sensor

Eng 2, Misfire

%

0

EGR Position Sensor

Eng 2, Eng 3

Volts

Varies

Engine Load

Eng 1, Eng 2, Eng 3, EVAP, Fuel Trim, Misfire

%

0

Engine Oil Level Switch

Eng 2, Eng 3

OK, Low

OK

Engine Oil Pressure Switch

Eng 3

OK, Low

OK

Engine Run Time

ALL

hrs./min./sec

Varies

Engine Speed

ALL

RPM

650 RPM (increases as engine speed increases)

EVAP Purge Solenoid Command

Eng 1, EVAP, Fuel Trim

%

Varies

EVAP Test Abort Reason

EVAP

Not Aborted, Lost Enable, Small Leak, Veh. Not At Rest

Not Aborted

EVAP Test Result

EVAP

No Result, Passed, Aborted, Fail- DTC P0440, Fail- DTC P0442, Fail- DTC P0446, Fail- DTC P1441

Passed

EVAP Test State

EVAP

Wait For Purge

Test Running

Test Complete

Test Complete

EVAP Vent Solenoid Command

Eng 1, EVAP, Fuel Trim

Venting/Not Venting

Venting

Extended Travel Brake Pedal Switch

Eng 1, Eng 2, Eng 3

Released, Applied

Released

FC Relay 1 Command

Eng 2, Eng 3

On, Off

On with low speed fan operation commanded

FC Relay 2 and S/P Command

Eng 2, Eng 3

On, Off

On with high speed fans commanded

Fuel Level

EVAP

Liters, Gallons

Varies

Fuel Level Sensor

EVAP

Volts

Varies

Fuel Pump Relay Command

Eng 1

On, Off

On

Fuel Tank Pressure Sensor

EVAP

Volts

Varies

Fuel Tank Pressure Sensor

Eng 1, EVAP

in H2O mmHg

Varies

Fuel Trim Cell

Eng 1, EVAP, Fuel Trim

#

Varies

Generator F Terminal Signal

Eng 2

%

Varies

Generator L Terminal Signal Command

Eng 2

On/Off

On

HO2S Bank 1 Sensor 1

Eng 1, EVAP, Fuel Trim

mV

Varying

HO2S Bank 1 Sensor 2

Eng 1, Fuel Trim

mV

Varying

HO2S Bank 2 Sensor 1

Eng 1, EVAP, Fuel Trim

mV

Varying

IAC Position

Eng 1, Fuel Trim

Counts

Varies

IAT Sensor

Eng 1, Eng 2, Eng 3, EVAP, Fuel Trim

°C, °F

Varies

IMS

Eng 3

Park, Park/Reverse, Reverse, Reverse/Neutral, Neutral, Neutral/Drive 4, Drive 4, Drive 4/Drive 3, Drive 3, Drive 3/Drive 2, Drive 2, Drive 2/Drive 1, Drive 1, Invalid

Park

Ignition 0 Signal

Eng 3

On, Off

On

Ignition 1 Signal

Eng 1, Eng 2, Eng 3, EVAP, Fuel Trim

Volts

Within 1 V of battery voltage

Injector PWM Bank 1 AVG

Eng 2, Fuel Trim, Misfire

ms

Varies

Injector PWM Bank 2 AVG

Eng 2, Fuel Trim, Misfire

ms

Varies

Knock Retard

Eng 1

Degrees

0

Long Term FT Avg. Bn1

Fuel Trim

%

Varies

Long Term FT Avg. Bn2

Fuel Trim

%

Varies

Long Term FT Bank 1

Eng 1, Eng 2, Eng 3, EVAP, Fuel Trim

%

-25% to +25%

Long Term FT Bank 2

Eng 1, Eng 2, Eng 3, EVAP, Fuel Trim

%

-25% to +25%

Loop Status

Eng 1, Eng 2, Eng 3, EVAP, Fuel Trim

Open Loop, Closed Loop

Closed

MAF Sensor

All

g/s

5.0-7.0

MAF Sensor

Eng 3

Hz

2800

MAP Sensor

Eng 1, Eng 2, Eng 3, Fuel Trim

Volts

1.50 V @ 38 kPa

MAP Sensor

Eng 1 Eng 2, Eng 3, EVAP, Fuel Trim, Misfire

kPa

30-50 kPa 1.50V @ 38 kPa

MIL Command

Eng 1

On, Off

Off

Mileage Since DTC Cleared

Eng 3

km/Miles

Varies

Misfire Current Cyl. 1 thru 8

Misfire

Counts

0-10

Misfire History Cyl. 1 thru 8

Misfire

Counts

0

Non-Driven Wheel Speed

Eng 2

km/h, mph

0, 2

Odometer

Eng 3

km, miles

Within 25.5 miles of IPC

PCM/VCM in VTD Fail Enable

Eng 3

Yes/No

No

Powertrain Induced Chassis Pitch Command

Eng 3

Active/Inactive

Inactive

Short Term FT Avg. Bn1

Fuel Trim

%

Varies

Short Term FT Avg. Bn2

Fuel Trim

%

Varies

Short Term FT Bank 1

Eng 1, Eng 2, Eng 3, EVAP, Fuel Trim

%

-8% to +8%

Short Term FT Bank 2

Eng 1, Eng 2, Eng 3, EVAP, Fuel Trim

%

-8% to +8%

Spark

Eng 1, Eng 2, Eng 3, Fuel Trim, Misfire

Degrees

Varies

Start Up ECT

Eng 2, EVAP, Fuel Trim

°C, °F

Depends on engine coolant temperature at start-up

Start Up IAT

EVAP, Fuel Trim

°C, °F

Depends on ambient temperature at start-up

Starter Relay Command

Eng 3

On, Off

Off

TCC Brake Pedal Switch

Eng 2, Eng 3

Released, Applied

Released

TCC Duty Cycle

Eng 2

%

0%

TCC Enable Solenoid Command

Eng 1

On/Off

Off

TFP Switch

Eng 2, Eng 3, Fuel Trim

Park/Neutral, Reverse, Drive, Invalid

Park/Neutral

TP Sensor

ALL

%

0%

TP Sensor

Eng 1, Eng 2, Eng 3

Volts

0.55/0.0

Torque Delivered Signal

Eng 2

%

Varies

Torque Request Signal

Eng 2

%

Varies

Traction Control Status

Eng 2

Active/Inactive

Inactive

Trans. Fluid Temp.

Eng 3

°C, °F

Varies with temperature

Vehicle Speed Sensor

ALL

km/h, mph

0

VTD Auto Learn Timer

Eng 3

Inactive, Active

Inactive

VTD Fuel Disable

Eng 3

Active/Inactive

Inactive

VTD Password

Eng 3

OK, Incorrect

OK

Warm-ups w/o Emission Faults

Eng 3

Counts

Varies

Warm-ups w/o Non-Emission Faults

Eng 3

Counts

Varies