|
|
Content .. 2835 2836 2837 2838 ..
the vehicle is in START or RUN and the Engine control module (ECM) receives the axle switch 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 Circuit/System Verification 1. Place the vehicle in 4WD install a scan tool and using engine data 2 look at the display for 4WD signal. 2. Verify that the scan tool indicates that the vehicle is in 4WD. If the scan tool indicates that the vehicle is in 2WD go to circuit system testing. Circuit/System Testing 1. Check the axle switch signal circuit for an open or high resistance. If everything checks normal then go to the next step. 2. Check the front axle actuator control circuit pin B at the front axle actuator connector or pin C at the transfer case shift control switch for an open or high resistance. If everything checks normal then short the axle actuator control circuit to ground this
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Transfer Case - MP 1222/1225/1226-NQG - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Instrument Panel Cluster (IPC) and Engine Control Module (ECM) Functionality If all circuits referenced above check good use the scan tool under engine data 2 to see if the scan If the scan tool indicates the vehicle is in 2WD then replace the engine control module, if Repair Procedures Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Instrument Cluster Replacement (without RPO SLT) Engine Control Module Replacement for the 4.3L engine Engine Control Module Replacement for the 4.8L, 5.3L, 6.0L, and 6.2L engine Engine Control Module Replacement for the 6.6L engine Control Module References for ECM replacement, setup, and programming Four-Wheel Drive Does Not Disengage Four-Wheel Drive Does Not Engage TRANSFER CASE POPPING NOISE TRANSFER CASE WHINE OR RUMBLE NOISE Cause Correction DEFINITION: A faulty internal transfer case component that causes a popping noise in the Chain jump Replace the chain and sprockets. Refer to Transfer Case Replace the shaft bearings. Refer to Transfer Case Inspect for damaged components caused by metal debris. Cause Correction
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Transfer Case - MP 1222/1225/1226-NQG - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
TRANSFER CASE GROWL OR GRINDING NOISE DEFINITION: A faulty internal transfer case component that causes a whine or rumbling Faulty bearings 1. Inspect all of the bearings and journals. Refer to Rear Output Shaft Cleaning and Inspection, Front 2. Replace any faulty bearings and any components with faulty bearing journals. Refer to Transfer Case Cause Correction DEFINITION: A faulty internal transfer case component that causes a growl or grinding High/low planetary carrier 1. Inspect the high/low planetary carrier assembly for the following conditions: Chipped, bent, or deformed teeth Planetary gear needle bearings worn Planetary gear thrust washers cracked or missing Seized or binding planetary gears Refer to High/Low Planetary Carrier Cleaning 2. Replace the high/low planetary carrier assembly if any of the above conditions exist. Refer to Transfer Case 1. Inspect the input shaft in the planetary carrier assembly for excessive thrust end play. 2. Inspect the input shaft teeth for the following conditions: Damage Worn or galled thrust surfaces
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Transfer Case - MP 1222/1225/1226-NQG - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
TRANSFER CASE CLUNK IN 2HI ONLY Input shaft Excessive wear Chipped teeth Metal embedded in the root of the teeth Refer to Front Output Shaft and Input Shaft 3. Replace the input shaft if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble. Thrust washers 1. Inspect for missing or damaged thrust washers for the input shaft. 2. Inspect the thrust washers for galling. 3. Replace the thrust washers if faulty and the mating component if damaged. Refer to Transfer Case High/low internal gear 1. Inspect the high/low internal gear teeth for the following conditions: Damage Chipped teeth Excessive wear Metal embedded in the root of the teeth Refer to Transfer Case Front Half Cleaning and 2. Replace the front case half if the high/low internal gear is faulty. Refer to Transfer Case Disassemble and Cause Correction DEFINITION: During acceleration or deceleration, a clunk is heard or felt in the transfer 1. Inspect the transfer case for the correct fluid level.
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Transfer Case - MP 1222/1225/1226-NQG - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Content .. 2835 2836 2837 2838 ..
|
|
|