Chevrolet Silverado / GMC Sierra. Service manual — part 2919

Scan Tool Data List

Scan Tool Data Definitions

Diagnostic Aids

Motor control A shorting to motor control B could cause this DTC.

Circuit/System Testing

1. Ignition off with a DMM check to see if motor A control and motor B control are shorted

together after disconnecting the transfer case control module and the transfer case actuator.

If motor A control is shorted to motor B control repair circuits as necessary. If the
circuits checked good go to next step.

2. Remove the transfer actuator and check to see if the shift detent shaft is binding.

If the shift lever detent shaft is binding refer to Transfer Case Disassemble. If the
shift lever detent shaft is not binding replace the transfer case actuator.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Transfer Case Two/Four Wheel Drive Actuator Replacement

Transfer Case Disassemble

DTC C0392

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0392 01

Rotational Position Sensor Circuit Short to Battery

DTC C0392 02

Rotational Position Sensor Circuit Short to Ground

2008 Chevrolet Silverado 1500

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

Silverado

DTC C0392 08

Rotational Position Sensor Circuit Signal Invalid

Diagnostic Fault Information

Circuit/System Description

The transfer case shift control module has an input from the transfer case two/four wheel drive
actuator position sensor otherwise know as a rotational position sensor (RPS). This sensor sends
the transfer case control module a pulse width modulated signal which will vary constantly
indicating the position of the transfer case actuator. This sensor also receives a 5-volt reference
signal from the transfer case control module. This sensor works in conjunction with the
incremental sensor which is inside the transfer case actuator. This sensor is more sensitive then the
incremental position sensor and indicates the exact position of the transfer case actuator, showing
the transfer case control module when the transfer case is between modes or ranges. It can also
show how much clutch activation is being commanded at any time.

Conditions for Running the DTC

The ignition is ON.

System voltage is 10.5-18 volts.

Conditions for Setting the DTC

The transfer case control module sees a PWM (RPS) voltage that does not constantly change
but remains high 5 volts or above indicating a short to voltage. Or it may remain low
indicating a short to ground 0.5 volts or less.

The module does not receive a 5-volt reference of 4.8-5.2 volts.

The RPS low reference circuits has an open or high resistance causing a low voltage
situation.

Action Taken When the DTC Sets

All shifting is disabled until the condition no longer exists.

The SERVICE 4WD indicator remains illuminated for the remainder of the current ignition

Circuit

Short to

Ground

Open/High

Resistance

Short to

Voltage

Signal

Invalid

Rotational Position Sensor
Circuit

DTC C0392

02

-

DTC C0392
01

DTC C0392

08

2008 Chevrolet Silverado 1500

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

Silverado

cycle.

Conditions for Clearing the DTC

The transfer case shift control module clears the DTC if the condition for setting the DTC is
not currently present.

A history DTC clears after 40 consecutive warm up cycles without a fault present.

History DTCs can be cleared using a scan tool.

Reference Information

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Scan Tool Data Definitions

Diagnostic Aids

A RPS signal voltage that remains low 0.5 or lower indicates a short to ground on the RPS signal
voltage circuit. It can also indicate an open or high resistance on the RPS low reference signal
circuit.

Circuit/System Testing

The RPS 5-volt reference circuit, RPS low reference circuit, and RPS sensor signal circuits
should be checked for shorts to ground, shorts to voltage, and opens or high resistance.

2008 Chevrolet Silverado 1500

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

Silverado

1. With the ignition on check the RPS 5-volt reference signal on the RPS connector pin 8 with

the connector disconnected using a DMM.

The DMM should indicate 4.8-5.2 volts, if the voltage is low check for an open or
high resistance or short to ground. If the voltage indicates the voltage is over the
specification check for a short to voltage. If the circuit checks good replace the
transfer case control module, program, and complete the motor learn procedure. If the
circuit checks good with the RPS disconnected, connect the RPS and see if the DTC
still show as current. If it does proceed to the next step.

2. With the transfer case shift control module connector X1 and X2 disconnected and the RPS

disconnected check the RPS signal circuit and the RPS low reference circuits for shorts to
ground, high resistance, or shorts to voltage.

If a shorting condition has been found then repair the circuits as necessary. If nothing is
found in circuit testing then replace the RPS, and perform the motor learn procedure.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TCSCM replacement, setup, and programming

Transfer Case High/Low Clutch Reset

Transfer Case Two/Four Wheel Drive Actuator Position Sensor Replacement

DTC C0396

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0396 01

Incremental Position Sensor Circuit Short to Battery

DTC C0396 02

Incremental Position Sensor Circuit Short to Ground

2008 Chevrolet Silverado 1500

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

Silverado