Hazard Lamps Malfunction
Hazard Lamps Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
Ground is applied at all times to the turn signal/multifunction switch from G201. The turn signal lamps may only be activated with the ignition switch in the ON position. The body control module (BCM) controls the vehicle turn signals based on inputs from the turn signal/multifunction switch. With the turn signal/multifunction switch in either the left or right turn position, a ground is applied through the turn signal switch signal circuit to the BCM indicating a turn signal request. When the specific request is seen, the BCM then applies a pulsating voltage through the front and rear turn signal supply voltage circuits illuminating the turn signal lamps.
When a turn signal request is seen by the BCM, a serial data message is sent to the instrument panel cluster (IPC) requesting the respective turn signal indicator be pulsed.
Circuit/System Verification
1. Ignition ON, observe the scan tool Left Turn Signal Switch parameter while using the turn signal/multifunction switch to turn the left turn signal on and off. The parameter should cycle between Active and Inactive.
• If the parameter does not cycle between the specified values, refer to Turn Signal/Multifunction Switch Circuit Test.
• If the parameter does cycle between the specified values and the left turn signal is inoperative, refer to the Turn Signal Circuit Test.
2. Observe the scan tool Right Turn Signal Switch parameter while using the turn signal/multifunction switch to turn the right turn signal on and off. The parameter should cycle between Active and Inactive.
• If the parameter does not cycle between the specified values, refer to Turn Signal/Multifunction Switch Circuit Test.
• If the parameter does cycle between the specified values and the right turn signal is inoperative, refer to the Turn Signal Circuit Test.
3. Ignition ON, place the turn signal/multifunction switch in the left turn position. The left turn signal indicator on the IPC should cycle ON and OFF.
• If the indicator is always OFF, replace the IPC.
4. Ignition ON, place the turn signal/multifunction switch in the right turn position. The right turn signal indicator on the IPC should cycle ON and OFF.
• If the indicator is always OFF, replace the IPC.
Circuit/System Testing
Turn Signal/Multifunction Switch Circuit Test.
1. Ignition OFF, disconnect the X2 harness connector at the turn signal/multifunction switch.
2. Verify that a test lamp illuminates between the ground circuit terminal B and B+.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Left Turn Signal Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal G for a short to ground. If the circuit tests normal, replace the BCM.
4. Verify the scan tool Right Turn Signal Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal H for a short to ground. If the circuit tests normal, replace the BCM.
5. Install a 3A fused jumper wire between the signal circuit terminal G and the ground circuit terminal B. Verify the scan tool Left Turn Signal Switch parameter is Active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
6. Install a 3A fused jumper wire between the signal circuit terminal H and the ground circuit terminal B. Verify the scan tool Right Turn Signal Switch parameter is Active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
7. If all circuits test normal, test or replace the turn signal/multifunction switch.
Turn Signal Circuit Test.
1. Ignition OFF, disconnect the X4 harness connector at the BCM.
2. Ignition ON, verify a test lamp illuminates between the following B+ terminals and ground.
* B+ terminal 1
* B+ terminal 2
* B+ terminal 3
• If the test lamp does not illuminate, test the B+ circuit for an open/high resistance. If the circuit fuse is open, test the B+ circuit and the respective turn signal circuits for a short to ground.
3. Ignition OFF, disconnect the harness connector at the inoperative turn signal lamp.
4. Test for less than 5.0 ohms of resistance between the ground circuit listed below and ground.
* Chevrolet front turn signal - terminal 2
* Pontiac front turn signal - terminal 3
* Suzuki left front turn signal - terminal G
* Suzuki right front turn signal - terminal 3
* Chevrolet and Pontiac rear turn signal - terminal GRND
* Suzuki rear turn signal - terminal G
• If greater than the specified range, test the ground circuit for an open/high resistance.
5. Connect a test lamp between the supply voltage circuit listed below and the ground circuit.
* Chevrolet or Pontiac front turn signal - terminal 1
* Suzuki left front turn signal - terminal MIN
* Suzuki right front turn signal - terminal 1
* Chevrolet and Pontiac rear turn signal - terminal Minor
* Suzuki rear turn signal - terminal MIN
6. Ignition ON, command the inoperative turn signal ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
7. If all circuits test normal, test or replace the appropriate turn signal lamp assembly.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
* Turn Signal Multifunction Switch Replacement