Chevrolet Silverado / GMC Sierra. Service manual — part 2909

DTC

Description

DTC B0770

B0770 01: AWD Indicator Circuit Short to Battery

B0770 06: AWD Indicator Circuit Short to Ground or Open

DTC B0775

B0775 01: 4 High Indicator Circuit Short to Battery

B0775 06: 4 High Indicator Circuit Short to Ground or Open

DTC B0780

B0780 01: 4 Low Indicator Circuit Short to Battery

B0780 06: 4 Low Indicator Circuit Short to Ground or Open

DTC B0785

B0785 01: 2 High Indicator Circuit Short to Battery

B0785 06: 2 High Indicator Circuit Short to Ground or Open

DTC B0790

B0790 01: Neutral Indicator Circuit Short to Battery

B0790 06: Neutral Indicator Circuit Short to Ground or Open

DTC B2725

B2725 08: Active Transfer Case Mode Switch Circuit

DTC C0306

C0306 02: Motor A or B Circuit Short to Ground

C0306 05: Motor A or B Circuit Short to Battery or Open

DTC C0321

C0321 01: Transfer Case Lock Circuit Short to Battery

C0321 02: Transfer Case Lock Circuit Short to Ground

C0321 04: Transfer Case Lock Circuit Open

C0321 08: Transfer Case Lock Circuit Signal Invalid

DTC C0374

C0374 54: General System Performance Temperature High

DTC C0379

C0379 01: Front Axle System Short to Battery

C0379 02: Front Axle System Short to Ground

C0379 04: Front Axle System Open Circuit

C0379 08: Front Axle System Signal Invalid

DTC C0387

C0387 59: Unable to Complete Shift Circuit/Component

Protection Timeout

DTC C0392

C0392 01: Rotational Position Sensor Circuit Short to Battery

C0392 02: Rotational Position Sensor Circuit Short to Ground

C0392 08: Rotational Position Sensor Circuit Signal Invalid

DTC C0396

C0396 01: Incremental Position Sensor Circuit Short to Battery

C0396 02: Incremental Position Sensor Circuit Short to

Ground

C0396 04: Incremental Position Sensor Open Circuit

C0396 05: Incremental Position Sensor Circuit Short to Battery

or Open

DTC C0397

C0397 64: Transfer Case Clutch Performance Actuator

Slipping

DTC C0398

C0398 5A: Incremental Sensor - Rotational Position Sensor

Correlation Plausibility Failure

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 3023/3024-NQH - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

DIAGNOSTIC STARTING POINT - TRANSFER CASE

Begin the system diagnosis with the Diagnostic System Check - Vehicle . The Diagnostic
System Check will provide the following information:

The identification of the control module or modules that command the system.

The ability of the control module or modules to communicate through the serial data circuit.

The identification of any stored diagnostic trouble codes (DTCs) and the status of the codes.

The use of the Diagnostic System Check - Vehicle will identify the correct procedure for
diagnosing the system and where the procedure is located.

SCAN TOOL OUTPUT CONTROLS

DTC C0550

C0550 37: Electronic Control Unit Malfunction

Watchdog/Safety Failure

C0550 39: Electronic Control Unit Malfunction Internal

Electronic Failure

DTC C0569

C0569 4B: System Configuration Error Calibration Data Not

Learned

DTC C0896

C0896 03: Device Voltage Range Voltage Below Threshold
C0896 07: Device Voltage Range Voltage Above Threshold

DTC P2160 or P2161

P2160: Vehicle Speed Sensor (VSS) 2 Circuit Low Voltage

P2161: Vehicle Speed Sensor (VSS) 2 Circuit Intermittent

Scan Tool

Output Control

Additional Menu

Selections

Description

Refer to the scan tool manual for complete scan tool operating instructions.

IMPORTANT:

Transmission must be in transmission neutral for any of these output controls to operate.

2WD High
Indicator Light

-

This function allows the technician to command the
2WD high indicator light, within the transfer case
shift control switch, on or off.

4WD High
Indicator Light

-

This function allows the technician to command the
4WD high indicator light, within the transfer case
shift control switch, on or off.

4WD Low

-

This function allows the technician to command the
4WD low indicator light, within the transfer case

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 3023/3024-NQH - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

SCAN TOOL DATA LIST

Indicator Light

shift control switch, on or off.

ATC Motor Learn -

This function allows the technician to command the
transfer case shift control module to relearn the
clutch status after the encoder motor, module, or
transfer case is replaced.

Auto 4WD
Indicator Light

-

This function allows the technician to command the
auto 4WD indicator light, within the transfer case
shift control switch, on or off.

Neutral Indicator
Light

-

This function allows the technician to command the
neutral indicator light, within the transfer case shift
control switch, on or off.

Scan Tool Parameter

Data List

Units Displayed

Typical Data

Value

Operating Conditions: Engine is at idle, upper radiator hose is hot, closed throttle,
gear is in Park or Neutral, and accessories are OFF.

2WD High Indicator Light

Transfer Case

Data

On/Off

On

4WD High Indicator Light

Transfer Case

Data

On/Off

Off

4WD Low Indicator Light

Transfer Case

Data

On/Off

Off

Accessory Status

Transfer Case

Data

Not Active/Active

Active

ATC Motor Init. Test

Transfer Case

Data

Not

Initialized/Passed/Failed/In

Progress

Passed

Auto 4WD Indicator Light

Transfer Case

Data

On/Off

On

Battery Voltage

Transfer Case

Data

Volts

Battery Voltage

Clutch Calibration Status

Transfer Case

Data

Not Learned/Initial

Learn/Normal Learn

Normal Learn

Clutch Coupling

Transfer Case

Data

0-100%

Varies

Transfer Case

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 3023/3024-NQH - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Front Axle Actuator

Data

Volts

Battery Voltage

Front Axle Actuator Status

Transfer Case

Data

Engaged/Disengaged

Disengaged

Front Axle Switch

Transfer Case

Data

Locked/Unlocked

Unlocked

Incremental Impulse Sensor

Transfer Case

Data

PWM Voltage

Varies

Incremental Position Sensor
Direction

Transfer Case

Data

Clockwise/Counter

Clockwise

Varies

Incremental Position Sensor

Transfer Case

Data

Degrees

Varies

Incremental Position Sensor

Transfer Case

Data

Volts

Varies

Mode Switch Return
Voltage

Transfer Case

Data

Volts

Varies

Mode Switch Selected

Transfer Case

Data

Auto 4WD/2 High/4High/4

Low/Neutral

2 High

Mode Switch Supply
Voltage

Transfer Case

Data

Volts

5 Volts

Motor Brake

Transfer Case

Data

Volts

Battery Voltage

Neutral Indicator Light

Transfer Case

Data

On/Off

Off

Rotational Position Sensor

Transfer Case

Data

Degrees

Varies

Rotational Position Sensor

Transfer Case

Data

Volts

Varies

Run/Crank

Transfer Case

Data

Active/Inactive

Active

Software Part Number

Transfer Case

Data

GM Part Number

Current Software

Release

Transfer Case Lock

Transfer Case

Data

Engaged/Disengaged

Disengaged

Transfer Case Motor

Transfer Case

Data

Amperage

0 Amps

Transfer Case Position

Transfer Case

Data

Current Transfer Case

Mode or Range

2 High

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Transfer Case - MP 3023/3024-NQH - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado