GM Service Manual Online
For 1990-2009 cars only
Table 1: DDM
Table 2: DIM
Table 3: IPM
Table 4: PCM
Table 5: PCM

DDM

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition: ON, Engine: OFF, Passenger HVAC Control: Neutral

Pass. HVAC Switch

Data Display

Counts

143

DIM

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Engine: ON, Ambient Temperature > 5°C (41°F), Mode: AUTO, Set Temperature: 18°C (65°F)

A/C Clutch (actual)

A/C Information

On/Off

On

A/C Clutch (desired)

A/C Information

On/Off

On

A/C Orifice Relay

A/C Information

Inactive/Active

Inactive

A/C Orifice Relay

Output Control

None/On/Off

None

A/C Pressure

A/C Information

Pressure

1004 kPa (146 psi)

Clutch Voltage

A/C Information

Normal/Low

Normal

Control Head (desired)

A/C Information

A/C On/A/C Off

A/C On

Evaporator Temp.

A/C Information

Degrees

Varies

Evaporator Temp Status

A/C Information

OK/Cold

OK

Pressure Status

A/C Information

Low/Normal/High

Normal

Temperature Status

A/C Information

OK/Hot

OK

IPM

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Ignition: ON, Engine: OFF

Inside Air Temp

HVAC Sensors

Degrees

23°C (74°F)

Left AC Duct Temp

HVAC Sensors

Degrees

23°C (74°F)

Left Duct Temp Desired

HVAC Sensors

Degrees

23°C (74°F)

Left HTR Duct Temp

HVAC Sensors

Degrees

23°C (74°F)

Left Solar

HVAC Sensors

Counts

0

Outside Air Temp

HVAC Sensors

Degrees

23°C (74°F)

Right AC Duct Temp

HVAC Sensors

Degrees

23°C (74°F)

Right Duct Temp Desired

HVAC Sensors

Degrees

23°C (74°F)

Right HTR Duct Temp

HVAC Sensors

Degrees

23°C (74°F)

Right Solar

HVAC Sensors

Counts

0

Ignition: ON, Engine: OFF, Mode: OFF

Commanded Blower

HVAC System Data

Percentile

0%

Ignition: ON, Engine: OFF, Mode: ANY except OFF, Fan: Low

Commanded Blower

HVAC System Data

Percentile

10%

Ignition: ON, Engine: OFF, Mode: ANY except OFF, Fan: HIGH

Commanded Blower

HVAC System Data

Percentile

100%

Ignition: ON, Engine: OFF, Mode: DEFROST (FRONT)

Selected Air Mode

HVAC System Data

Status

Defrost

Ignition: ON, Engine: OFF, Mode: DEFOG (WINDSHIELD/FLOOR)

Selected Air Mode

HVAC System Data

Status

Defog

Ignition: ON, Engine: OFF, Mode: UPPER (MID)

Selected Air Mode

HVAC System Data

Status

Upper

Ignition: ON, Engine: OFF, Mode: BI-LEVEL (MID/FLOOR)

Selected Air Mode

HVAC System Data

Status

Bi-Level

Ignition: ON, Engine: OFF, Mode: HEATER (FLOOR)

Selected Air Mode

HVAC System Data

Status

Heater

Ignition: ON, Engine: OFF, Mode: AUTO, Temperature: 18°C (65°F) (OAT above 5°C (41°F))

A/C Requested

HVAC System Data

Yes/No

Yes

Engine: ON, Mode: AUTO, Temperature: 18°C (65°F)

Coolant Temperature

HVAC System Data

Degrees

71°C (159°F)

Ignition: ON, Engine: OFF, Mode: ANY except OFF, Temperature: 18°C (65°F)

Left Temp. Dr. Actual

HVAC Door Positions

Counts/Volts

30 Counts (0.61 Volts)

Left Temp. Dr. Commanded

HVAC Door Positions

Counts/Volts

30 Counts (0.61 Volts)

Right Temp. Dr. Actual

HVAC Door Positions

Counts/Volts

214 Counts (4.29 Volts)

Right Temp. Dr. Commanded

HVAC Door Positions

Counts/Volts

214 Counts (4.29 Volts)

Ignition: ON, Engine: OFF, Mode: ANY except OFF, Temperature: 29°C (85°F)

Left Temp Dr Actual

HVAC Door Positions

Counts/Volts

214 Counts (4.29 Volts)

Left Temp. Dr. Commanded

HVAC Door Positions

Counts/Volts

214 Counts (4.29 Volts)

Right Temp Dr Actual

HVAC Door Positions

Counts/Volts

37 Counts (0.74 Volts)

Right Temp. Dr. Commanded

HVAC Door Positions

Counts/Volts

37 Counts (0.74 Volts)

Ignition: ON, Engine: OFF, Mode: DEFROST (FRONT)

HTR/DEF/AC Dr Actual

HVAC Door Positions

Counts/Volts

19 Counts (0.38 Volts)

HTR/DEF/AC Dr Commanded

HVAC Door Positions

Counts/Volts

19 Counts (0.38 Volts)

Ignition: ON, Engine: OFF, Mode: HEATER (FLOOR)

HTR/DEF/AC Dr Actual

HVAC Door Positions

Counts/Volts

132 Counts (2.64 Volts)

HTR/DEF/AC Dr Commanded

HVAC Door Positions

Counts/Volts

132 Counts (2.64 Volts)

Ignition: ON, Engine: OFF, Mode: BI-LEVEL (MID/FLOOR)

HTR/DEF/AC Dr Actual

HVAC Door Positions

Counts/Volts

185 Counts (3.63 Volts)

HTR/DEF/AC Dr Commanded

HVAC Door Positions

Counts/Volts

185 Counts (3.63 Volts)

Ignition: ON, Engine: OFF, Mode: DEFOG (WINDSHIELD/FLOOR)

HTR/DEF/AC Dr Actual

HVAC Door Positions

Counts/Volts

53 Counts (1.04 Volts)

HTR/DEF/AC Dr Commanded

HVAC Door Positions

Counts/Volts

53 Counts (1.04 Volts)

Ignition: ON, Engine: OFF, Mode: UPPER (MID)

HTR/DEF/AC Dr Actual

HVAC Door Positions

Counts/Volts

233 Counts (4.66 Volts)

HTR/DEF/AC Dr Commanded

HVAC Door Positions

Counts/Volts

233 Counts (4.66 Volts)

Ignition: ON, Engine: OFF, Mode: ANY except AUTO, Recirc: OFF

Air Inlet Dr Actual

HVAC Door Positions

Counts/Volts

32 Counts (0.65 Volts)

Air Inlet Dr Commanded

HVAC Door Positions

Counts/Volts

32 Counts (0.65 Volts)

Ignition: ON, Engine: OFF, Mode: RECIRC+ANY except DEFROST

Air Inlet Dr Actual

HVAC Door Positions

Counts/Volts

202 Counts (4.04 Volts)

Air Inlet Dr Commanded

HVAC Door Positions

Counts/Volts

202 Counts (4.04 Volts)

Ignition: ON, Engine: OFF

Air Inlet Door Position

HVAC Motors

None/Outside Recirc.

None

Afterblow

Set Options

Enable/Disable

Enable

Blower Motor

Miscellaneous Tests

None/On/Off

None

HTR/DEF/AC Door Position

HVAC Motors

None/Defrost/AC

None

Inside Air Temp

Open/Short Data

Counts/Volts

139 Counts (2.72 Volts)

Instant OAT Update

Miscellaneous Tests

None/On

None

Left AC Duct Temp

Open/Short Data

Counts/Volts

136 Counts (2.67 Volts)

Left HTR Duct Temp

Open/Short Data

Counts/Volts

136 Counts (2.67 Volts)

Left Solar Sensor

Open/Short Data

Counts/Volts

232 Counts (4.55 Volts)

Left Temp Door Position

HVAC Motors

None/Hot/Cold

None

Max Air Inlet Dr Pos

HVAC Door Calibrations

Counts/Volts

202 Counts (4.04 Volts)

Max HTR/DEF/AC Dr Pos

HVAC Door Calibrations

Counts/Volts

233 Counts (4.66 Volts)

Max Left Temp Dr Pos.

HVAC Door Calibrations

Counts/Volts

214 Counts (4.29 Volts)

Max Right Temp Dr Pos

HVAC Door Calibrations

Counts/Volts

214 Counts (4.29 Volts)

Min Air Inlet Dr Pos

HVAC Door Calibrations

Counts/Volts

32 Counts (0.65 Volts)

Min HTR/DEF/AC Dr Pos

HVAC Door Calibrations

Counts/Volts

19 Counts (0.38 Volts)

Min Left Temp Dr Pos.

HVAC Door Calibrations

Counts/Volts

30 Counts (0.61 Volts)

Min Right Temp Dr Pos.

HVAC Door Calibrations

Counts/Volts

37 Counts (0.74 Volts)

Outside Air Temp

Open/Short Data

Counts/Volts

95 Counts (1.86 Volts)

Recalibrate All Motors

Miscellaneous Tests

None/On

None

Relearn Control Panel Type

Miscellaneous Tests

None/On

None

Right AC Duct Temp

Open/Short Data

Counts/Volts

136 Counts (2.67 Volts)

Right HTR Duct Temp

Open/Short Data

Counts/Volts

136 Counts (2.67 Volts)

Right Solar Sensor

Open/Short Data

Counts/Volts

232 Counts (4.55 Volts)

Right Temp Door Position

HVAC Motors

None/Hot/Cold

None

Temperature Offset

Set Options

-5/+5

0 Offset

PCM

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Engine: ON, Ambient Temperature > 5°C (41°F), Mode: AUTO, Set Temperature: 18°C (65°F)

A/C Relay Command

Engine Data 1

ON/OFF

OFF

ECT

Engine Data 1

Temperature

-40  to +215°C

(-40 to +420°F)

A/C High Side Pressure

Engine Data 2

kPa

0 to 4000  kPa

(0 to 580  psi)

A/C High Side Pressure

Engine Data 2

Volts

0 to 5  Volts

A/C Off for WOT

Engine Data 2

No/Yes

No

A/C Pressure Disable

Engine Data 2

Yes/No

No

A/C Request Signal

Engine Data 2

No/Yes

Yes

A/C Relay

Engine Output Controls

Ok/Fault

OK

A/C Relay Command

Engine Data 2

On/Off

Off

PCM

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Engine: ON, Ambient Temperature > 5°C (41°F), Mode: AUTO, Set Temperature: 18°C (65°F)

A/C High Side Pressure

Engine Data 2

kPa

(psi)

0 to 4000  kPa

(0 to 580  psi)

A/C Relay Command

Engine Data 1

On/Off

On

A/C Relay Command

Engine Data 2

On/Off

On

A/C Relay Command

Engine Data 3

On/Off

On

A/C Relay

Engine Output Controls

On/Off

On/Off

ECT

Engine Data 3

Degrees

-40  to +215°C

(-40 to +420°F)

ECT

Engine Data 1

Degrees

-40  to +215°C

(-40 to +420°F)

ECT

Engine Data 2

Degrees

-40  to +215°C

(-40 to +420°F)