Symptom Troubleshooting Index

NOTE: Most problems in the SH-AWD unit can be diagnosed by identifying noises from the gears or bearings. Care should be taken during diagnosis not to confuse differential noises with those from other drivetrain components.

Symptom	Diagnostic Procedure	Also check for
The SH-AWD indicator does not go off, and no DTCs are stored	Symptom troubleshooting (see THE SH-AWD INDICATOR DOES NOT GO OFF, AND NO DTCS ARE STORED ).	Low battery voltage
The SH-AWD indicator does not come on	Symptom troubleshooting (see THE SH-AWD INDICATOR DOES NOT COME ON ).
Gear or bearing noises	Inspect and/or replace the rear differential fluid (see REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT ). Inspect the side case clearance (see SIDE CASE REPLACEMENT ). Replace the rear differential carrier assembly.	Worn or cupped tires Tire inflation Fluid condition Incorrect side case clearance Damaged or chipped gears Incorrect tire size (rolling circumference)
Rear differential overheats	Inspect and/or replace the rear differential fluid (see REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT ). Inspect the tires.	Fluid condition Incorrect tire size (rolling circumference)
Rear differential leaks fluid	Inspect fluid leaks. Inspect and/or replace the rear differential fluid (see REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT ). Replace the side case oil seal (see SIDE CASE OIL SEAL REPLACEMENT ). Replace the center case assembly (see CENTER CASE REPLACEMENT ).	Fluid condition Clogged breather hose Worn or damaged oil seal Damaged sealing washer Loose mounting bolts or inadequate sealing
Rear differential screeches, whines, moans, or squeaks	Inspect and/or replace the rear differential fluid (see REAR DIFFERENTIAL FLUID INSPECTION AND REPLACEMENT ). Inspect the tires. Replace the rear differential carrier assembly.	Worn or cupped tires Tire inflation Fluid condition Incorrect tire size (rolling circumference) Damaged oil pump
Noise during acceleration, or when accelerating from a full stop	Inspect the side case clearance (see SIDE CASE REPLACEMENT ). Inspect the tires. Replace the rear differential carrier assembly.	Worn or cupped tires Tire inflation Incorrect side case clearance Incorrect tire size (rolling circumference)
HDS does not communicate with the SH-AWD control unit or the vehicle	Troubleshooting the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).