Pinpoint Test N: One Turn Signal/Hazard Lamp Is Inoperative/Always On

Turn Signal and Hazard Lamps

Pinpoint Tests

Pinpoint Test N: One Turn Signal/Hazard Lamp Is Inoperative/Always On

Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number

Normal Operation

When the Generic Electronic Module (GEM) detects the multifunction switch in the LH TURN position, the GEM provides on/off voltage to the LH front and rear turn lamps.

When the GEM detects the multifunction switch in the RH TURN position, the GEM provides on/off voltage to the RH front and rear turn lamps.

- DTC B1499 (Lamp Turn Signal Left Circuit Failure) - a continuous and on-demand DTC that sets when the GEM detects an open or short to voltage from the LH turn lamp output circuit.
- DTC B1503 (Lamp Turn Signal Right Circuit Failure) - a continuous and on-demand DTC that sets when the GEM detects an open or short to voltage from the RH turn lamp output circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Bulb holder
- Rear lamp jumper harness
- Headlamp assembly
- GEM


PINPOINT TEST N: ONE TURN SIGNAL/HAZARD LAMP IS 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.

-------------------------------------------------
N1 DETERMINE IF A TURN LAMP IS ALWAYS ON


- Ignition ON.
- Monitor the turn lamps.
- Is any turn lamp always on?

Yes
GO to N2.

No
GO to N3.

-------------------------------------------------
N2 CHECK THE GEM TURN LAMP OUTPUT CIRCUITS FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: GEM C201e.
- Ignition ON.
- Does the turn lamp in question continue to illuminate?

Yes
For the LH front turn lamp, REPAIR circuit 49S-LG5 (BU/WH). TEST the system for normal operation. For the RH front turn lamp, REPAIR circuit 49S-LG2 (BU/RD). TEST the system for normal operation. For the LH rear turn lamp, REPAIR circuit 49S-LG12 (BU). TEST the system for normal operation. For the RH rear turn lamp, REPAIR circuit 49S-LG19 (BU/RD). TEST the system for normal operation.

No
GO to N8.

-------------------------------------------------
N3 CHECK FOR VOLTAGE TO THE TURN LAMP


- Ignition OFF.
- Activate the hazard flasher lamp function.
- Measure the voltage between the inoperative turn lamp, harness side and ground as follows:









- Does the voltage alternate between 0 and greater than 10 volts?

Yes
GO to N4.

No
If an individual front or the corresponding side turn lamp is inoperative, REPAIR the voltage supply circuit for an open. TEST the system for normal operation. If a front and the corresponding side turn lamp are both inoperative, GO to N6. For a rear turn lamp, GO to N6.

-------------------------------------------------
N4 CHECK FOR VOLTAGE TO THE TURN LAMP USING THE CONNECTOR GROUND


- Measure the voltage between the inoperative turn lamp connector, harness side as follows:









- Does the voltage alternate between 0 and greater than 10 volts?

Yes
For a side turn lamp, INSTALL a new bulb holder. TEST the system for normal operation. For a front turn lamp, GO to N5. For a rear turn lamp, REPAIR or INSTALL a new rear lamp jumper harness. TEST the system for normal operation.

No
REPAIR the ground circuit in question for an open. TEST the system for normal operation.

-------------------------------------------------
N5 CHECK THE FRONT BULB HOLDER


- Inspect the front bulb holder for damage.
- Is the front bulb holder OK?

Yes
REPAIR or INSTALL a new headlamp assembly. REFER to Headlamp Assembly Service and Repair. TEST the system for normal operation.

No
INSTALL a new bulb holder. TEST the system for normal operation.

-------------------------------------------------
N6 CHECK THE GEM TURN LAMP OUTPUT CIRCUIT FOR A SHORT TO GROUND


NOTE: If the front turn lamp and corresponding side turn lamp are both inoperative, make sure both lamps are disconnected for correct test results.

- Turn the hazard lamp function off.
- Disconnect: GEM C201e.
- Measure the resistance between the GEM, harness side and ground as follows:









- Is the resistance greater than 10,000 ohms?

Yes
GO to N7.

No
REPAIR the circuit in question for a short to ground. TEST the system for normal operation.

-------------------------------------------------
N7 BYPASS THE GEM


- Disconnect: Inoperative Turn Lamp.
- For an inoperative LH front and side turn lamp, connect a fused jumper wire between the GEM C201e-4, circuit 29-LG26 (OG), harness side and the GEM C201e-3, circuit 49S-LG5 (BU/WH), harness side.




- For an inoperative RH front and side turn lamp, connect a fused jumper wire between the GEM C201e-4, circuit 29-LG26 (OG), harness side and the GEM C201e-6, circuit 49S-LG2 (BU/RD), harness side.




- For an inoperative LH rear turn lamp, connect a fused jumper wire between the GEM C201e-4, circuit 29-LG26 (OG), harness side and the GEM C201e-2, circuit 49S-LG12 (BU), harness side.




- For an inoperative RH rear turn lamp, connect a fused jumper wire between the GEM C201e-4, circuit 29-LG26 (OG), harness side and the GEM C201e-1, circuit 49S-LG19 (BU/RD), harness side.




- Does the turn lamp in question illuminate?

Yes
REMOVE the jumper wire. GO to N8.

No
REMOVE the jumper wire. REPAIR the GEM turn lamp output circuit in question for an open. TEST the system for normal operation.

-------------------------------------------------
N8 CHECK FOR CORRECT GEM OPERATION


- Ignition OFF.
- 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 Multifunction Electronic Modules Service and Repair. 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.

-------------------------------------------------