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Pinpoint Test J: One Or More Stoplamps Are Inoperative




Stoplamps

Pinpoint Tests


Pinpoint Test J: 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 Body Control Module B (BCM-B) detects the brake pedal is applied, the BCM-B provides voltage to the high mounted stoplamp and each individual LED lamp within the LH and RH rear stoplamps.





This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Rear lamp jumper harness
- LED lamp
- High mounted stoplamp
- BCM-B



PINPOINT TEST J: 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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J1 DETERMINE THE INOPERATIVE STOPLAMP


- Ignition OFF.
- Apply the brake pedal and observe the stoplamps.
- Are all the stoplamps inoperative?

Yes
GO to Pinpoint Test I. Pinpoint Test I: All The Stoplamps Are Inoperative

No
For the high mounted stoplamp, GO to J2.

For a LH rear stoplamp, GO to J8.

For a RH rear stoplamp, GO to J17.

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J2 CHECK FOR DTC B1270:15


- Review the results from the BCM-B self-test.
- Is DTC B1270:15 present?

Yes
GO to J3.

No
GO to J6.

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J3 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 CLS17 (YE/GY), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to J4.

No
GO to J5.

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J4 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 CLS17 (YE/GY), 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 circuit GD110 (BK/WH) for an open. TEST the system for normal operation.

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J5 CHECK THE HIGH MOUNTED STOPLAMP SUPPLY CIRCUIT FOR AN OPEN


- Disconnect: BCM-B C4368a.
- Measure the resistance between the high mounted stoplamp C475-1, circuit CLS17 (YE/GY), harness side and the BCM-B C4368a-18, circuit CLS17 (YE/GY), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to J26.

No
REPAIR circuit CLS17 (YE/GY) for an open. TEST the system for normal operation.

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J6 CHECK THE HIGH MOUNTED STOPLAMP FOR A SHORT TO GROUND


- Disconnect: High Mounted Stoplamp C475.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: BCM-B Self-Test.
- Clear the DTCs and repeat the self-test (required to enable the stoplamp output driver if DTC U1000:00 is present).
- While applying the brake pedal, measure the voltage between the high mounted stoplamp C475-1, circuit CLS17 (YE/GY), harness side and ground.




- 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
GO to J7.

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J7 CHECK THE HIGH MOUNTED STOPLAMP SUPPLY CIRCUIT FOR A SHORT TO GROUND


- Ignition OFF.
- Disconnect: BCM-B C4368a.
- Measure the resistance between the high mounted stoplamp C475-1, circuit CLS17 (YE/GY), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to J26.

No
REPAIR circuit CLS17 (YE/GY) for a short to ground. After the repair:

If no DTCs are present, TEST the system for normal operation.

If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the stoplamp output driver). TEST the system for normal operation.

If DTC U3000:49 is present, INSTALL a new BCM-B. REFER to Body Control Systems. TEST the system for normal operation.

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J8 CHECK IF ALL 3 LH STOPLAMPS ARE INOPERATIVE


- Apply the brake pedal and observe the LH rear stoplamps.
- Are all 3 LH stoplamps inoperative?

Yes
GO to J9.

No
GO to J10.

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J9 CHECK THE LH REAR JUMPER HARNESS (ALL 3 LAMPS ARE INOPERATIVE)


- Disconnect: LH Rear Lamp C498.
- Inspect the LH rear lamp jumper harness for opens.
- Is the LH rear lamp jumper harness OK?

Yes
REPAIR circuit GD109 (BK) for an open. CLEAR the DTCs. REPEAT the self-test.

No
REPAIR or INSTALL a new rear lamp jumper harness. CLEAR the DTCs. REPEAT the self-test.

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J10 CHECK FOR A LH REAR LAMP OPEN CIRCUIT DTC


- Review the results from the BCM-B self-test.
- Is DTC B1271:15, B1274:15 or B1275:15 present?

Yes
GO to J11.

No
GO to J14.

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J11 CHECK FOR VOLTAGE TO THE LH REAR STOPLAMP


- Disconnect: LH Rear Lamp C498.
- While applying the brake pedal, measure the voltage between the LH rear lamp, harness side and ground as follows:









- Is the voltage greater than 10 volts?

Yes
GO to J12.

No
GO to J13.

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J12 CHECK THE LH REAR LAMP JUMPER HARNESS FOR OPENS


- Inspect the LH rear lamp jumper harness for opens.
- Is the LH rear lamp jumper harness OK?

Yes
INSTALL a new LED lamp. CLEAR the DTCs. REPEAT the self-test.

No
REPAIR or INSTALL a new rear lamp jumper harness. CLEAR the DTCs. REPEAT the self-test.

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J13 CHECK THE BCM-B LH REAR STOPLAMP OUTPUT CIRCUIT FOR AN OPEN


- Disconnect: BCM-B C4368a.
- Measure the resistance between the LH rear lamp, harness side and BCM-B, harness side as follows:









- Is the resistance less than 5 ohms?

Yes
GO to J26.

No
REPAIR the circuit in question for an open. CLEAR the DTCs. REPEAT the self-test.

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J14 ISOLATE THE LH REAR LAMP SHORT TO GROUND


- Disconnect: LH Rear Lamp C498.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: BCM-B Self-Test.
- Clear the DTCs and repeat the self-test (required to enable the stoplamp output driver if DTC U1000:00 is present).
- While applying the brake pedal, measure the voltage between the LH rear lamp, harness side and ground as follows:









- Is the voltage greater than 10 volts?

Yes
GO to J15.

No
GO to J16.

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J15 CHECK THE LH REAR LAMP JUMPER HARNESS FOR A SHORT TO GROUND


- Inspect the LH rear lamp jumper harness for shorts.
- Is the LH rear lamp jumper harness OK?

Yes
INSTALL a new LED lamp. CLEAR the DTCs. REPEAT the self-test.

No
REPAIR or INSTALL a new rear lamp jumper harness. CLEAR the DTCs. REPEAT the self-test.

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J16 CHECK THE BCM-B LH REAR STOPLAMP OUTPUT CIRCUIT FOR A SHORT TO GROUND


- Ignition OFF.
- Disconnect: BCM-B C4368a.
- Measure the resistance between the LH rear stoplamp, harness side and ground as follows:









- Is the resistance greater than 1000 ohms?

Yes
GO to J26.

No
REPAIR the circuit in question for a short to ground. After the repair:

If no DTCs are present, TEST the system for normal operation.

If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the stoplamp output driver). TEST the system for normal operation.

If DTC U3000:49 is present, INSTALL a new BCM-B. REFER to Body Control Systems. TEST the system for normal operation.

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J17 CHECK IF ALL 3 RH STOPLAMPS ARE INOPERATIVE


- Apply the brake pedal and observe the RH rear stoplamps.
- Are all 3 RH stoplamps inoperative?

Yes
GO to J18.

No
GO to J19.

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J18 CHECK THE RH REAR JUMPER HARNESS (ALL 3 LAMPS ARE INOPERATIVE)


- Disconnect: RH Rear Lamp C499.
- Inspect the RH rear lamp jumper harness for opens.
- Is the RH rear lamp jumper harness OK?

Yes
REPAIR circuit GD110 (BK/WH) for an open. CLEAR the DTCs. REPEAT the self-test.

No
REPAIR or INSTALL a new rear lamp jumper harness. CLEAR the DTCs. REPEAT the self-test.

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J19 CHECK FOR A RH REAR LAMP OPEN CIRCUIT DTC


- Review the results from the BCM-B self-test.
- Is DTC B1272:15, B1273:15 or B1276:15 present?

Yes
GO to J20.

No
GO to J23.

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J20 CHECK FOR VOLTAGE TO THE RH REAR STOPLAMP


- Disconnect: RH Rear Lamp C499.
- While applying the brake pedal, measure the voltage between the RH rear lamp, harness side and ground as follows:









- Is the voltage greater than 10 volts?

Yes
GO to J21.

No
GO to J22.

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J21 CHECK THE RH REAR LAMP JUMPER HARNESS FOR OPENS


- Inspect the RH rear lamp jumper harness for opens.
- Is the RH rear lamp jumper harness OK?

Yes
INSTALL a new LED lamp. CLEAR the DTCs. REPEAT the self-test.

No
REPAIR or INSTALL a new rear lamp jumper harness. CLEAR the DTCs. REPEAT the self-test.

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J22 CHECK THE BCM-B RH REAR STOPLAMP OUTPUT CIRCUIT FOR AN OPEN


- Measure the resistance between the RH rear lamp, harness side and BCM-B C4298a, harness side.









- Is the resistance less than 5 ohms?

Yes
GO to J26.

No
REPAIR the circuit in question for an open. CLEAR the DTCs. REPEAT the self-test.

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J23 ISOLATE THE RH REAR LAMP SHORT TO GROUND


- Disconnect: RH Rear Lamp C499.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: BCM-B Self-Test.
- Clear the DTCs and repeat the self-test (required to enable the stoplamp output driver if DTC U1000:00 is present).
- While applying the brake pedal, measure the voltage between the RH rear lamp, harness side and ground as follows:









- Is the voltage greater than 10 volts?

Yes
GO to J24.

No
GO to J25.

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J24 CHECK THE RH REAR LAMP JUMPER HARNESS FOR A SHORT TO GROUND


- Inspect the RH rear lamp jumper harness for shorts.
- Is the RH rear lamp jumper harness OK?

Yes
INSTALL a new LED lamp. CLEAR the DTCs. REPEAT the self-test.

No
REPAIR or INSTALL a new rear lamp jumper harness. CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
J25 CHECK THE BCM-B RH REAR STOPLAMP OUTPUT CIRCUIT FOR A SHORT TO GROUND


- Ignition OFF.
- Disconnect: BCM-B C4368a.
- Measure the resistance between the RH rear inoperative stoplamp, harness side and ground.









- Is the resistance greater than 10,000 ohms?

Yes
GO to J26.

No
REPAIR the circuit in question for a short to ground. After the repair:

If no DTCs are present, TEST the system for normal operation.

If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the stoplamp output driver). TEST the system for normal operation.

If DTC U3000:49 is present, INSTALL a new BCM-B. REFER to Body Control Systems. TEST the system for normal operation.

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J26 CHECK FOR CORRECT BCM-B OPERATION


- Disconnect all the BCM-B connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the BCM-B 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 BCM-B. 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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