Chevrolet Silverado / GMC Sierra. Manual — part 2960
The HVAC control module monitors the voltage level on the supply voltage circuit of the rear
defog relay. The voltage level should be low while the rear defog relay is de-energized. The
voltage will be near system voltage when the HVAC control module energizes the rear defog
relay.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
The HVAC control module detects a short to ground or open/high resistance in the rear defog
relay control circuit for 1 second or greater.
Action Taken When the DTC Sets
The HVAC control module stores the DTC to memory.
The rear window defogger will not operate.
Conditions for Clearing the DTC
The DTC will be current for as long as the fault is present.
When the fault is no longer present, the DTC will be a history DTC.
A history DTC will clear after 50 ignition cycles.
Reference Information
Schematic Reference
Defogger Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Rear Window Defogger Description and Operation
Electrical Information Reference
Circuit Testing
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - Cab & Chassis Sierra, Cab & Chassis Silverado,
Sierra & Silverado
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the operation of the defogger grid while pressing and depressing the rear
defogger switch. The defogger grid should ACTIVATE and DEACTIVATE when changing
between commanded states.
Circuit/System Testing
1. Ignition OFF, disconnect the REAR DEFOG relay.
2. Test for less than 1.0 ohm between the ground circuit terminal 85 and ground.
If greater than the specified range, test the relay coil ground circuit for an open/high
resistance.
3. Connect a test lamp between the control circuit terminal 86 and ground.
4. Ignition ON, command the defogger grid ON and OFF by pressing and depressing the rear
defogger switch. The test lamp should turn ON and OFF when changing between the
commanded states.
If the test lamp is always ON, test the control circuit for a short to voltage. If the
circuit tests normal, replace the HVAC control module.
If the test lamp is always OFF, test the control circuit for a short to ground or an
open/high resistance. If the circuit tests normal, replace the HVAC control module.
5. If all circuits test normal, test or replace the REAR DEFOG relay.
Component Testing
1. Ignition OFF, disconnect the REAR DEFOG relay.
2. Test for 60-180 ohms between terminals 85 and 86.
If not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals:
30 and 86
30 and 87
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - Cab & Chassis Sierra, Cab & Chassis Silverado,
Sierra & Silverado
30 and 85
85 and 87
If not the specified value, replace the relay.
4. Install a 25-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper
wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30
and 87.
If greater than the specified range, replace the relay.
Repair Procedures
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Relay Replacement (Attached to Wire Harness) or Relay Replacement (Within an
Electrical Center)
Control Module References for HVAC control module replacement, setup and
programming
DTC B3205
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 Descriptors
DTC B3205 00
Window Inactive Over Current Fault
DTC B3205 0B
Window Motor Fast Over Current Fault
Diagnostic Fault Information
Circuit
Short to
Ground
Open/High
Resistance
Short to
Voltage
Signal
Performance
Driver Door Switch B+
1, 3
1
-
-
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - Cab & Chassis Sierra, Cab & Chassis Silverado,
Sierra & Silverado
Circuit/System Description
The driver door switch (DDS) and passenger door switch (PDS) control the power window
functions through the power window motor up and down control circuits. The door switches
monitor the control circuits for fault conditions when up or down operation is requested prior to
activating the function and during operation.
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
LR Window Switch B+
1, 3
3
-
-
Passenger Door Switch B+
2, 4
2
-
-
RR Window Switch B+
2, 4
4
-
-
Power Window Switch Right
Rear Down Signal
B3823 00
B3823 00
B3823 00
-
Power Window Switch Right
Rear Up Signal
B3822 00
B3822 00
B3822 00
-
Power Window Switch Left
Rear Down Signal
B3820 00
B3820 00
B3820 00
-
Power Window Switch Left
Rear Up Signal
B3819 00
B3819 00
B3819 00
-
Power Window Lockout Left
Rear Control
B3821 00
B3821 00
B3821 00
-
Power Window Lockout Right
Rear Control
B3824 00
B3824 00
B3824 00
-
LR Window Motor Control
3
3
3
-
Passenger Window Motor
Control
B3205 00
B3205 0B
B3205 00
-
RR Window Motor Control
4
4
4
-
Driver Window Motor
Control
B3205 00
B3205 0B
B3205 00
-
LR Window Switch Ground
-
3
3
-
RR Window Switch Ground
-
4
4
-
1. Driver Window Malfunction
2. Passenger Window Malfunction
3. Left Rear Window Malfunction
4. Right Rear Window Malfunction
2008 Chevrolet Silverado 1500
2008 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - Cab & Chassis Sierra, Cab & Chassis Silverado,
Sierra & Silverado
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст