GM Service Manual Online
For 1990-2009 cars only

Scan Tool Parameter

Units Displayed

Data List

Typical Data Value

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

5 Volt Reference 1

OK, Fault

Eng 1

--

5 Volt Reference 2

OK, Fault

Eng 1

--

12 Volt Reference

OK, Fault

Eng 1

--

24X Crank Sensor

RPM

Eng 2, Misfire

--

A/C High Side Pressure

Volts

Eng 2

--

A/C Relay Command

On, Off

Eng 1, Eng 2, Eng 3, Misfire

OFF, unless commanded ON

AIR Fuel Ratio

: 1

Eng 2, Eng 3, EVAP, Fuel Trim

14.5-14.9

AIR Pump Relay Command

On, Off

Eng 1, Fuel Trim

--

Air Solenoid Command

On, Off

Eng 1, Fuel Trim

--

BARO

kPa

Eng 1, EVAP, Fuel Trim

85-103 kPa

CKP Sensor Status

Angle, Time A, Time B

Misfire

--

CMP Sensor

RPM

Eng 2, Misfire

--

CMP Sensor Signal Present

Yes/No

Misfire

Yes

Crank Request Signal

No, Yes

Eng 3

--

Cruise Control Active

No, Yes

Eng 2, Eng 3

No

Cruise Inhibited Signal Command

On, Off

Eng 3

On

Current Gear

1, 2, 3, 4

Eng 1, Eng 2, Fuel Trim

1

Cycles of Misfire Data

Counts

Misfire

Varies

Desired EGR Position

%

Eng 2

--

Desired Idle Speed

RPM

Eng 1, Eng 2, Eng 3, EVAP

650 RPM

ECT Sensor

°C, °F

ALL

Varies

EGR Position Sensor

%

Eng 2, Misfire

--

EGR Position Sensor

Volts

Eng 2, Eng 3

--

Engine Load

%

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

--

Engine Oil Level Switch

OK, Low

Eng 2, Eng 3

OK

Engine Oil Pressure Switch

OK, Low

Eng 3

OK

Engine Run Time

hrs./min./sec

ALL

--

Engine Speed

RPM

ALL

650 RPM (increases as engine speed increases)

EVAP Purge Solenoid Command

%

Eng 1, EVAP, Fuel Trim

Varies

EVAP Test Abort Reason

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

EVAP

--

EVAP Test Result

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

EVAP

--

EVAP Test State

Wait For Purge

Test Running

Test Complete

EVAP

--

EVAP Vent Solenoid Command

Venting / Not Venting

Eng 1, EVAP, Fuel Trim

Venting

Extended Travel Brake Pedal Switch

Released, Applied

Eng 1, Eng 2, Eng 3

Released

FC Relay 1 Command

On, Off

Eng 2, Eng 3

On with low speed fan operation commanded

FC Relay 2 and 3 Command

On, Off

Eng 2, Eng 3

On with high speed fans commanded

Fuel Level

Liters, Gallons

EVAP

--

Fuel Level Sensor

Volts

EVAP

--

Fuel Pump Relay Command

On, Off

Eng 1

On

Fuel Tank Pressure Sensor

Volts

EVAP

Varies

Fuel Tank Pressure Sensor

in H2O mmHg

Eng 1, EVAP

Varies

Fuel Trim Cell

#

Eng 1, EVAP, Fuel Trim

--

Generator F Terminal Signal

%

Eng 2

Varies

Generator L Terminal Signal Command

On / Off

Eng 2

On

HO2S Bank 1 Sensor 1

mV

Eng 1, EVAP, Fuel Trim

Varying

HO2S Bank 1 Sensor 2

mV

Eng 1, Fuel Trim

Varying

HO2S Bank 2 Sensor 1

mV

Eng 1, EVAP, Fuel Trim

Varying

HO2S Warm-Up Bank 1 Sensor 2

Seconds

Fuel Trim

Varies

IAC Position

Counts

Eng 1, Fuel Trim

--

IAT Sensor

°C, °F

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

--

IMS

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

Eng 3

Park

Ignition 0 Signal

On, Off

Eng 3

On

Ignition 1 Signal

Volts

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

Within 1 V of battery voltage

Injector PWM Bank 1

ms

Eng 2, Fuel Trim, Misfire

--

Injector PWM Bank 2

ms

Eng 2, Fuel Trim, Misfire

--

Injector PWM Bank 1 AVG

ms

Eng 2, Fuel Trim, Misfire

--

Injector PWM Bank 2 AVG

ms

Eng 2, Fuel Trim, Misfire

--

Knock Retard

Degrees

Eng 1

0

Long Term FT Avg. Bn1

%

Fuel Trim

--

Long Term FT Avg. Bn2

%

Fuel Trim

--

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

Open Loop, Closed Loop

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

Closed

MAF Sensor

g/s

All

5.0-7.0

MAF Sensor

Hz

Eng 3

2800

MAP Sensor

Volts

Eng 1, Eng 2, EVAP

1.50 V @ 38 kPa

MAP Sensor

kPa

Eng 1 Eng 2, Eng 3, EVAP, Misfire

30-50 kPa 1.50V @ 38 kPa

MIL Command

On, Off

Eng 1

Off

Mileage Since DTC Cleared

km / Miles

Eng 3

--

Misfire Current Cyl. 1 thru 8

Counts

Misfire

0-10

Misfire History Cyl. 1 thru 8

Counts

Misfire

0

Non-Driven Wheel Speed

km/h, mph

Eng 2

0, 2

Odometer

km, miles

Eng 3

Within 25.5 miles of IPC

PCM / VCM in VTD Fail Enable

Yes / No

Eng 3

No

Powertrain Induced Chassis Pitch Command

Active / Inactive

Eng 3

Inactive

Short Term FT Avg. Bn1

%

Fuel Trim

--

Short Term FT Avg. Bn2

%

Fuel Trim

--

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

Degrees

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

Varies

Start Up ECT

°C, °F

Eng 2, EVAP, Fuel Trim

Depends on engine coolant temperature at start-up

Start Up IAT

°C, °F

EVAP

Depends on ambient temperature at start-up

Starter Relay Command

On, Off

Eng 3

Off

TCC Brake Pedal Switch

Released, Applied

Eng 2, Eng 3

Released

TCC Duty Cycle

%

Eng 2

0%

TCC Enable Solenoid Command

On / Off

Eng 1

Off

TFP Switch

Park/Neutral, Reverse, Drive, Invalid

Eng 2, Eng 3, Fuel Trim

Park/Neutral

TP Sensor

%

ALL

0%

TP Sensor

Volts

Eng 1, Eng 2, Eng 3

0.55/0.0

Torque Delivered Signal

%

Eng 2

--

Torque Request Signal

%

Eng 2

--

Traction Control Status

Active / Inactive

Eng 2

Inactive

Trans. Fluid Temp.

°C, °F

Eng 3

Varies with temperature

Vehicle Speed Sensor

km/h, mph

ALL

0

VTD Auto Learn Timer

Inactive, Active

Eng 3

Inactive

VTD Fuel Disable

Active / Inactive

Eng 3

Inactive

VTD Password

OK, Incorrect

Eng 2

OK

Warm-ups w/o Emission Faults

Counts

Eng 3

--

Warm-ups w/o Non-Emission Faults

Counts

Eng 3

--