|
|
Content .. 2492 2493 2494 2495 ..
Control Module References for Scan Tool Information Circuit/System Verification 1. Ignition ON, observe the scan tool BCM Stop Lamp Switch Status parameter while pressing and releasing the brake pedal. The reading should change between 1 count and If not the specified value, refer to the Stop Lamp Switch Circuit Test below. 2. Ignition ON, observe the scan tool TCM Brake Switch parameter while pressing and releasing the brake pedal. The reading should change between Pressed and Released. If not the specified value, refer to the Brake Switch Circuit Test below. 3. Ignition ON, observe the left, and right stop lamps while pressing and releasing the brake pedal. The stop lamps should turn on and off. If the left and or right stop lamps are always on or inoperative, refer to the Stop Lamp 4. Connect a test lamp between the relay side of the CHMSL fuse and ground. 5. Verify that the test lamp turns on and off while pressing and releasing the brake pedal. If the test lamp does not turn on and off while changing between the commanded 6. If the center high mount stop lamp is always on or inoperative refer to the CHMSL Circuit Test below. Circuit/System Testing Stop Lamp Switch Circuit Test 1. Ignition OFF, disconnect the harness connector at the stop lamp switch. 2. Ignition ON, test for battery voltage between the 12-volt reference circuit terminal C and ground. If less than the specified range, test the 12-volt reference circuit for a short to ground 3. Verify the scan tool BCM Stop Lamp Switch Status parameter is approximately 1023 counts. If not the specified value, test the signal circuit terminal D for a short to voltage. If the 4. Install a 3A fused jumper wire between the signal circuit terminal D and the 12-volt reference circuit terminal C. Verify the scan tool Stop Lamp Switch Status parameter is 1
2008 Chevrolet Silverado 1500 2008 ACCESSORIES & EQUIPMENT Lighting - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
If not the specified value, test the signal circuit for an open/high resistance. If the 5. If all circuits test normal, test or replace the stop lamp switch. Brake Switch Circuit Test 1. Ignition OFF, disconnect the harness connector at the stop lamp switch. 2. Ignition ON, test for battery voltage between the ignition supply circuit terminal B and ground. If less than the specified range, test the ignition supply circuit for a short to ground or 3. Verify the scan tool TCM Brake Switch parameter is Released. If not the specified value, test the signal circuit terminal A for a short to voltage. 4. Install a 3A fused jumper wire between the signal circuit terminal B and the ignition supply circuit terminal A. Verify the scan tool Brake Switch parameter is Applied. If not the specified value, test the signal circuit for an open/high resistance. 5. If all circuits test normal, test or replace the stop lamp switch. Stop Lamp Circuit Test 1. Ignition OFF, disconnect the harnes connector X4 at the BCM. 2. Ignition ON, verify a test lamp illuminates between the terminals listed below and ground. Terminal 1 Terminal 2 Terminal 4 If the test lamp does not illuminate, test the B+ circuit for an open/high resistance or 3. Connect the harnes connector X4 at the BCM. 4. Ignition OFF, disconnect the harness connector at the affected stop lamp. 5. Test for less than 1 ohm of resistance between the ground circuit terminal GRD and ground. If greater than the specified range, test the ground circuit for an open/high resistance. 6. Connect a test lamp between the stop lamp control circuit terminal MJR and ground. 7. Ignition ON, press and release the brake pedal. 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.
2008 Chevrolet Silverado 1500 2008 ACCESSORIES & EQUIPMENT Lighting - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
If the test lamp is always OFF, test the control circuit for a short to ground or an 8. If all circuits test normal, test or replace the affected stop lamp. CHMSL Relay Control Circuit Test 1. Ignition OFF, disconnect the harness connector X5 at the BCM. 2. Ignition ON, verify the center high mount stop lamp is not on. If the center high mount stop lamp is on, test the CHMSL relay control circuit terminal 3. Install a 10A fused jumper wire between the CHMSL relay control circuit terminal 5 and battery voltage. Verify the center high mount stop lamp is on. If the center high mount stop lamp is not on or the fuse in the jumper wire opens, test 4. If all circuits test normal, replace the BCM. CHMSL Circuit Test 1. Ignition OFF, disconnect the harnes connector at the center high mount stop lamp. 2. Test for less than 1 ohm of resistance between the ground circuit terminal 1 and ground. If greater than the specified range, test the ground circuit for an open/high resistance. 3. Connect a test lamp between the control circuit terminal A and the ground circuit terminal B. 4. Ignition ON, press and release the brake pedal. 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 test lamp is always OFF, test the control circuit for a short to ground or an 5. If all circuits test normal, test or replace the center high mounted stop lamp. Repair Procedures Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Stop Lamp Switch Replacement (Non-Adjustable Pedal) or Stop Lamp Switch
2008 Chevrolet Silverado 1500 2008 ACCESSORIES & EQUIPMENT Lighting - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
High Mount Stop Lamp Replacement (Regular Cab) or High Mount Stop Lamp Tail Lamp Bulb Replacement (GMC) or Tail Lamp Bulb Replacement (Chevrolet) Control Module References for BCM replacement, programming, and setup. TURN SIGNAL LAMPS AND/OR INDICATORS MALFUNCTION 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. Circuit/System Description When the turn signal switch is placed in either the left or right position, a ground signal is Reference Information Schematic Reference Fog Lights Schematics Connector End View Reference Component Connector End Views Description and Operation Exterior Lighting Systems Description and Operation Electrical Information Reference
2008 Chevrolet Silverado 1500 2008 ACCESSORIES & EQUIPMENT Lighting - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Content .. 2492 2493 2494 2495 ..
|
|
|