Pinpoint Test M: The Hazard Lamps Are Inoperative/Always On
Turn Signal and Hazard Lamps
Pinpoint Tests
Pinpoint Test M: The Hazard Lamps Are Inoperative/Always On
Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The Generic Electronic Module (GEM) sends a voltage signal to the hazard flasher lamp switch. When the hazard flasher lamp switch is pressed, the voltage signal is routed to ground. When the GEM detects a request for the hazard lamps, the GEM provides on/off voltage to the all turn lamps.
The hazard flasher lamp switch is a momentary contact switch.
- DTC B1875 (Turn Signal/Hazard Switch Signal Circuit Failure) - an on-demand DTC that sets when the GEM detects an open from the hazard flasher lamp switch input circuit. The on-demand self-test requires the hazard flasher lamp switch to be pressed during the test. If the GEM does not detect the switch pressed during the self test, the DTC is set.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Hazard flasher lamp switch
- GEM
PINPOINT TEST M: THE HAZARD LAMPS ARE INOPERATIVE/ALWAYS ON
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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M1 CHECK FOR CORRECT TURN SIGNAL OPERATION
- Ignition ON.
- Place the multifunction switch in the LH and RH TURN positions.
- Do the turn signals operate correctly?
Yes
GO to M2.
No
GO to Pinpoint Test J. Pinpoint Test J: The Turn Signal Lamps Are Inoperative
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M2 CHECK FOR A VOLTAGE SIGNAL TO THE HAZARD FLASHER LAMP SWITCH
- Ignition OFF.
- Disconnect: Hazard Flasher Lamp Switch C2039.
- Measure the voltage between the hazard flasher lamp switch C2039-6, circuit 91S-LG8 (BK/OG), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to M3.
No
GO to M4.
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M3 CHECK FOR A VOLTAGE SIGNAL TO THE HAZARD FLASHER LAMP SWITCH USING THE CONNECTOR GROUND
- Measure the voltage between the hazard flasher lamp switch C2039-6, circuit 91S-LG8 (BK/OG), harness side and the hazard flasher lamp switch C2039-4, circuit 91-LG8 (BK/OG), harness side.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new hazard flasher lamp switch. REFER to Hazard Flasher Lamp Switch Service and Repair. TEST the system for normal operation.
No
REPAIR the hazard flasher lamp switch ground circuit for an open. TEST the system for normal operation.
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M4 CHECK THE HAZARD FLASHER LAMP REQUEST INPUT CIRCUIT FOR A SHORT TO GROUND
- Disconnect: GEM C201b.
- Measure the resistance between the hazard flasher lamp switch C2039-6, circuit 91S-LG8 (BK/OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to M5.
No
REPAIR circuit 91S-LG8 (BK/OG) for a short to ground. TEST the system for normal operation.
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M5 CHECK THE HAZARD FLASHER LAMP REQUEST INPUT CIRCUIT FOR AN OPEN
- Measure the resistance between the GEM C201b-16, circuit 91S-LG8 (BK/OG), harness side and the hazard flasher lamp switch C2039-6, circuit 91S-LG8 (BK/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to M6.
No
REPAIR circuit 91S-LG8 (BK/OG) for an open. TEST the system for normal operation.
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M6 CHECK FOR CORRECT GEM OPERATION
- Disconnect all the GEM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the GEM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new GEM. REFER to Body Control Systems. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
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