Pinpoint Test L: One Or More Stoplamps Are Inoperative
Stoplamps
Pinpoint Test L: 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 voltage is supplied to the Smart Junction Box (SJB) and the high mounted stoplamp.
When the SJB detects the brake pedal is applied, the SJB provides voltage to the LH and RH rear stoplamps.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- High mounted stoplamp
- Rear lamp assembly
- SJB
PINPOINT TEST L: 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.
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L1 DETERMINE THE INOPERATIVE STOPLAMP
- Ignition OFF.
- Apply the brake pedal and observe the stoplamps.
- Are all the stoplamps imperative?
Yes
GO to Pinpoint Test K. Pinpoint Test K: All The Stoplamps Are Inoperative
No
If the high mounted stoplamp is inoperative, GO to L2.
If an individual rear stoplamp is inoperative, GO to L5.
If both rear stoplamps are inoperative, VERIFY the SJB fuse 6 (20A) is OK. If OK, GO to L4. If not OK, REFER to the Wiring Diagrams to identify the possible cause of the circuit short. Diagrams By Number
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L2 CHECK FOR VOLTAGE TO THE HIGH MOUNTED STOPLAMP
- Disconnect: High Mounted Stoplamp C904.
- While applying the brake pedal, measure the voltage between the high mounted stoplamp C904-A, circuit CLS43 (YE/GN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to L3.
No
REPAIR the circuit. TEST the system for normal operation.
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L3 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 C904-A, circuit CLS43 (YE/GN), harness side and the high mounted stoplamp C904-B, circuit GD149 (BK/GY), 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 circuit GD149 (BK/GY) for an open. TEST the system for normal operation.
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L4 CHECK FOR VOLTAGE TO THE SJB
- Disconnect: SJB C2280b.
- While applying the brake pedal, measure the voltage between the SJB C2280b-40, circuit CLS43 (YE/GN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to L10.
No
REPAIR circuit CLS43 (YE/GN) for an open. TEST the system for normal operation.
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L5 CHECK FOR VOLTAGE TO THE REAR LAMP
- Disconnect: Inoperative Rear Lamp.
- While applying the brake pedal, measure the voltage between the LH rear lamp C498-1, circuit CLS18 (GY/BN), harness side and ground; or between the RH rear lamp C499-1, circuit CLS19 (VT/OG), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to L6.
No
GO to L7.
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L6 CHECK FOR VOLTAGE TO THE REAR LAMP USING THE CONNECTOR GROUND
- While applying the brake pedal, measure the voltage between the LH rear lamp C498-1, circuit CLS18 (GY/BN), harness side and the LH rear lamp C498-2, circuit GD149 (BK/GY), harness side; or between the RH rear lamp C499-1, circuit CLS19 (VT/OG), harness side and the RH rear lamp C499-2, circuit GD148 (BK/YE), harness side.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new rear lamp assembly. REFER to Rear Lamp Assembly [1][2]Rear Lamp Assembly. TEST the system for normal operation.
No
REPAIR circuit GD149 (BK/GY) (LH rear lamp) or circuit GD148 (BK/YE) (RH rear lamp). CLEAR the DTCs. REPEAT the self-test.
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L7 REPEAT THE ON-DEMAND SELF-TEST AND RECHECK FOR VOLTAGE TO THE REAR LAMP
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Clear the DTCs and repeat the self-test (required to enable the stoplamp output driver if DTC B106E is present).
- While applying the brake pedal, measure the voltage between the LH rear lamp C498-1, circuit CLS18 (GY/BN), harness side and ground; or between the RH rear lamp C499-1, circuit CLS19 (VT/OG), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new rear lamp assembly. REFER to Rear Lamp Assembly [1][2]Rear Lamp Assembly. TEST the system for normal operation.
No
GO to L8.
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L8 CHECK THE REAR STOPLAMP VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Corresponding Trailer Tow Stop/Turn Relay.
- Disconnect: SJB C2280d.
- Measure the resistance between the SJB C2280d-25, circuit CLS18 (GY/BN), harness side and ground; or between the SJB C2280d-26, circuit CLS19 (VT/OG), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to L9.
No
REPAIR circuit CLS18 (GY/BN) (LH rear stoplamp) or circuit CLS19 (VT/OG) (RH rear stoplamp) for a short to ground. After the repair:
If no DTCs are present, TEST the system for normal operation.
If DTC B106E is present, CLEAR the DTCs and REPEAT the self-test (required to enable the stoplamp output driver if DTC B106E is present). TEST the system for normal operation.
If DTC B106F is present, INSTALL a new SJB. REFER to Multifunction Electronic Modules Smart Junction Box (SJB). TEST the system for normal operation.
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L9 CHECK THE REAR STOPLAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Measure the resistance between the LH rear lamp C498-1, circuit CLS18 (GY/BN), harness side and the SJB C2280d-25, circuit CLS18 (GY/BN), harness side; or between the RH rear lamp C499-1, 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 L10.
No
REPAIR circuit CLS18 (GY/BN) (LH rear stoplamp) or circuit CLS19 (VT/OG) (RH rear stoplamp) for an open. TEST the system for normal operation.
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L10 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. REFER to Multifunction Electronic Modules Smart Junction Box (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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