Chevrolet Silverado / GMC Sierra. Service manual — part 732

Whine/Growl Noise That Changes with Vehicle Speed

Noise in First or Reverse Gear

Noise in First, Second, Third, Fourth, Fifth, or Reverse Gear

Noise in First, Second, Sixth, or Reverse Gear

Noise in Second or Sixth Gear

Noise During 3-4 or 4-3 Shifts

Noise in Fourth, Fifth, or Sixth Gear

Vibration

Vibration in Second, Third, Fourth, Fifth, or Sixth Gear

Flexplate/Torque Converter Vibration Test

Noise and Vibration Analysis

Range Performance Diagnosis

No Park or Drive

No Drive in All Ranges

No Reverse Gear

No Drive or Reverse Gear

Shift Quality Feel Diagnosis

Harsh Garage Shift

Harsh, Soft, Delayed or Slipping First or Reverse Gear

Harsh, Soft, Delayed or Slipping 1-2-3-4 Shift

Harsh, Soft, Delayed or Slipping 4-5-6 Shift

Harsh, Soft, Delayed or Slipping Third, Fifth, or Reverse Gear

Harsh, Soft, Delayed or Slipping Second or Sixth Gear

Shift Pattern

No First Gear

No First and Reverse Gears

No First, Second, Third, and Fourth Gear

No First, Second, Third, Fourth, Fifth, or Reverse Gear

No Second and Sixth Gear

No First, Second, Sixth, or Reverse Gear

No Fourth, Fifth, and Sixth Gear

No Third, Fifth, and Reverse Gear

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Stuck in Second or Sixth Gear

Stuck in First or Reverse Gear

Torque Converter Diagnosis

Torque Converter Diagnosis

No Torque Converter Clutch Apply

No Torque Converter Clutch Release

Symptom Not Found or No Symptom Detected

Transmission Fluid Check

Road Test

Line Pressure Check

CONTROL SOLENOID VALVE AND TRANSMISSION CONTROL MODULE
ASSEMBLY INSPECTION

Fig. 1: Identifying Control Solenoid Valve & Transmission Control Module Assembly
Courtesy of GENERAL MOTORS CORP.

1. Inspect the control solenoid (w/body and TCM) valve assembly connectors and pins (2, 3,

4) for the following conditions:

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Damage

Bent pins

Debris

Broken retaining tab

Contamination

2. Ensure no metallic debris is inside the connectors near the terminal pins.

3. Inspect the control solenoid (w/body and TCM) valve assembly solenoid leads (1) for

contamination or metallic debris.

4. Inspect the 4 control solenoid (w/body and TCM) valve assembly filter plate retaining tabs

(5) for cracks and ensure proper tension when filter plate is attached.

CONTROL SOLENOID VALVE AND TRANSMISSION CONTROL MODULE
ASSEMBLY INPUT SHAFT SPEED/OUTPUT SHAFT SPEED INPUT TEST

Tools Required

J 35616 GM-Approved Terminal Test Kit

J 38522 Variable Signal Generator

TEST

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Fig. 2: Identifying J 35616 And J 38522
Courtesy of GENERAL MOTORS CORP.

The purpose of this test is to provide a simulated input/output speed sensor (ISS/OSS) signal to
the control solenoid (w/body and TCM) valve assembly ISS/OSS input circuits.

1. Disconnect the ISS/OSS wiring harness connector from the control solenoid (w/body and

TCM) valve assembly.

2. Using the J 35616 , connect the J 38522 to the affected ISS or OSS signal circuit on the

control solenoid (w/body and TCM) valve assembly.

1. Set the J 38522 Signal to 8 volts, the Frequency to 120 and the Percent Duty Cycle to

50.

2. Ignition On, observe either the scan tool parameter ISS Signal or OSS Signal.

3. The signal parameter should display between 100-400 RPM.

If the signal display is not in this range, the control solenoid (w/body and TCM) valve
assembly is not reading the input signal correctly and is faulty.

CONTROL SOLENOID VALVE AND TRANSMISSION CONTROL MODULE
ASSEMBLY CLEANING

The control solenoid (w/body and TCM) valve assembly cleaning procedure is a specific
software based routine, which resides in the TCM. This procedure is activated by the scan tool
and is used to cycle the solenoids and valves in the control solenoid valve assembly in an attempt
to dislodge debris and free up the valves after a performance diagnostic trouble code (DTC) has
set. When the cleaning procedure is completed, the DTC enable criteria should be run again, to
see if the DTC concern has been corrected.

1. Operate the transmission to achieve 70°-90°C (158°-194°F).

2. With a scan tool, select the Service Cleaning Procedure. Initiate the cleaning procedure.

3. When the cleaning procedure is completed, shut OFF the ignition for 30 seconds.

4. Restart the engine and operate the vehicle based on the criteria specified in Conditions for

Running the DTC.

5. Observe if the applicable DTC or DTCs have run and passed to verify if the cleaning

procedure was effective.

CONTROL SOLENOID VALVE AND TRANSMISSION CONTROL MODULE
ASSEMBLY SOLENOID PERFORMANCE TEST

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Automatic Transmission - 6L50/6L80/6L90 - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado