Pinpoint Test I: One or More Stoplamps Are Inoperative
Stoplamps
Pinpoint Tests
Pinpoint Test I: One Or More Stoplamps Are Inoperative
Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number
Normal Operation
When the brake pedal is applied, the stoplamp switch routes voltage to the Smart Junction Box (SJB) and the high mounted stoplamp through circuit CCB08 (VT/WH). When the SJB detects the brake pedal is applied, the SJB provides voltage to the LH and RH rear stoplamps through circuits CLS18 (GY/BN) and CLS19 (VT/OG). Ground for the all the stoplamps is provided through circuit GD110 (BK/WH).
The SJB fuse 6 (20A) supplies voltage for all the stop and turn lamps.
B2044-B2047:
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Bulb holder
- High mounted stoplamp
- SJB
PINPOINT TEST I: ONE OR MORE STOPLAMPS ARE INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Make sure the bulb is good before continuing diagnostics.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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I1 DETERMINE THE INOPERATIVE STOPLAMP
- Ignition OFF.
- Apply the brake pedal and observe the stoplamps.
- Are all the stoplamps inoperative?
Yes
Go To Pinpoint Test h. Pinpoint Test H: All The Stoplamps Are Inoperative
No
If the high mounted stoplamp is inoperative, GO to I2.
If both rear lamps are inoperative, VERIFY the SJB fuse 6 (20A) is OK. If OK, GO to I4. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short.
If one rear lamp is inoperative, GO to I5.
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I2 CHECK FOR VOLTAGE TO THE HIGH MOUNTED STOPLAMP
- Disconnect: High Mounted Stoplamp C475.
- While applying the brake pedal, measure the voltage between the high mounted stoplamp C475-1, circuit CCB08 (VT/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to I3.
No
REPAIR circuit CCB08 (VT/WH) for an open. TEST the system for normal operation.
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I3 CHECK FOR VOLTAGE TO THE HIGH MOUNTED STOPLAMP USING THE CONNECTOR GROUND
- While applying the brake pedal, measure the voltage between the high mounted stoplamp C475-1, circuit CCB08 (VT/WH), harness side and the high mounted stoplamp C475-2, circuit GD110 (BK/WH), harness side.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new high mounted stoplamp. REFER to High Mounted Stoplamp Service and Repair. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
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I4 CHECK FOR VOLTAGE TO THE SJB
- Disconnect: SJB C2280b.
- While applying the brake pedal, measure the voltage between the SJB C2280b-40, circuit CCB08 (VT/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to I11.
No
REPAIR circuit CCB08 (VT/WH) for an open. TEST the system for normal operation.
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I5 USE THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check the recorded results from the SJB on-demand self-test.
- Was DTC B2045 or B2047 present?
Yes
GO to I6.
No
GO to I9.
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I6 CHECK FOR VOLTAGE TO THE BULB HOLDER
- Disconnect: Inoperative Rear Lamp.
- While applying the brake pedal, measure the voltage between the LH rear lamp C4035-3, circuit CLS18 (GY/BN), harness side and ground; or between the RH rear lamp C4032-3, circuit CLS19 (VT/OG), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to I7.
No
GO to I8.
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I7 CHECK CIRCUIT GD110 (BK/WH) FOR AN OPEN
- While applying the brake pedal, measure the voltage between the LH rear lamp C4035-3, circuit CLS18 (GY/BN), harness side and the LH rear lamp C4035-1, circuit GD110 (BK/WH), harness side; or between the RH rear lamp C4032-3, circuit CLS19 (VT/OG), harness side and the RH rear lamp C4032-1, circuit GD110 (BK/WH), harness side.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new bulb holder. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR circuit GD110 (BK/WH) for an open. CLEAR the DTCs. REPEAT the self-test.
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I8 CHECK CIRCUIT CLS18 (GY/BN) OR CIRCUIT CLS19 (VT/OG) FOR AN OPEN
- Disconnect: SJB C2280d.
- Measure the resistance between the LH rear lamp C4035-3, circuit CLS18 (GY/BN), harness side and the SJB C2280d-25, circuit CLS18 (GY/BN), harness side; or between the RH rear lamp C4032-3, circuit CLS19 (VT/OG), harness side and the SJB C2280d-26, circuit CLS19 (VT/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to I11.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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I9 CHECK THE LH BULB HOLDER FOR A SHORT TO GROUND
- Disconnect: Inoperative Rear Lamp C4035.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Clear the DTCs and repeat the SJB on-demand self-test.
- While applying the brake pedal, measure the voltage between the LH rear lamp C4035-3, circuit CLS18 (GY/BN), harness side and ground; or between the RH rear lamp C4032-3, circuit CLS19 (VT/OG), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new bulb holder. TEST the system for normal operation.
No
GO to I10.
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I10 CHECK CIRCUIT CLS18 (GY/BN) OR CIRCUIT CLS19 (VT/OG) FOR A SHORT TO GROUND
- Disconnect: SJB C2280d.
- Measure the resistance between the SJB C2280d-25 (DTC B2044), circuit CLS18 (GY/BN), harness side and ground; or between the SJB C2280d-26 (DTC B2046), circuit CLS19 (VT/OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to I11.
No
REPAIR the circuit in question for a short to ground. RUN the on-demand self-test (required to clear certain DTCs). CORRECT any unresolved DTCs. CLEAR all DTCs. TEST the system for normal operation.
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I11 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB 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 SJB. 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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