Pinpoint Test Z: The Individual Trailer Lamp Is Inoperative - LH Stop/Turn Lamp
Trailer Lamps
Pinpoint Tests
Pinpoint Test Z: The Individual Trailer Lamp Is Inoperative - LH Stop/Turn Lamp
Refer to Wiring Diagram Set 95, Trailer/Camper Adapter for schematic and connector information. Diagrams By Number
Normal Operation
Voltage to the LH trailer stop/turn lamp is supplied by the Smart Junction Box (SJB) through circuit CAT06 (YE).
- DTC B2070 (Trailer Tow Relay Coil(s) Circuit Failure) - a continuous DTC that sets when the SJB detects a short to ground from the LH trailer stop/turn lamp voltage supply circuit. The self-test must be run after the repair in order for the SJB to enable the output for the LH trailer stop/turn lamp voltage supply. A trailer equipped with too many LH stop/turn bulbs may also set the DTC.
This pinpoint test is intended to diagnose the following:
- Trailer equipped with too many bulbs
- Wiring, terminals or connectors
- Trailer tow connector
- Trailer
- SJB
PINPOINT TEST Z: THE INDIVIDUAL TRAILER LAMP IS INOPERATIVE - LH STOP/TURN LAMP
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Before beginning diagnostics, visually inspect the trailer tow connector for signs of corrosion or damage. Repair or install a new trailer tow connector as required.
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Z1 CHECK THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check the recorded results from the SJB self-test.
- Was DTC B2070 present?
Yes
GO to Z2.
No
GO to Z6.
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Z2 CLEAR THE DTCs AND REPEAT THE ON-DEMAND SELF-TEST WITH THE TRAILER DISCONNECTED
- Disconnect the trailer from the vehicle.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Clear the continuous DTCs. Repeat the on-demand self-test.
- Is DTC B2070 still present?
Yes
For the 4-pin connector, GO to Z5.
For the 7-pin connector, GO to Z4.
No
GO to Z3.
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Z3 CHECK THE NUMBER OF BULBS ON THE TRAILER
- Inspect the trailer for more than 2 LH stop/turn lamp bulbs.
- Are more than 2 LH stop/turn lamp bulbs present?
Yes
INFORM the customer that the vehicle can only support 2 stop/turn lamp bulbs per side. Any additional stop/turn lamp bulbs need to be removed from the trailer or an adapter kit installed for the trailer tow lamps to operate correctly.
No
The vehicle is operating correctly. SEND the trailer to an authorized camper/trailer repair facility.
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Z4 CHECK THE TRAILER TOW CONNECTOR
- Disconnect: Trailer Tow C473.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Clear the continuous DTCs. Repeat the on-demand self-test.
- Is DTC B2070 still present?
Yes
GO to Z5.
No
INSTALL a new trailer tow connector. TEST the system for normal operation.
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Z5 CHECK CIRCUIT CAT06 (YE) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280a.
- Measure the resistance between the SJB C2280a-14, circuit CAT06 (YE), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to Z9.
No
REPAIR the circuit. 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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Z6 CHECK FOR VOLTAGE TO THE TRAILER TOW CONNECTOR
- Disconnect the trailer from the vehicle.
- Ignition OFF.
- For the 4-pin connector, while applying the brake pedal, measure the voltage between the trailer tow C439-2, circuit CAT06 (YE), harness side and ground.
- For the 7-pin connector, while applying the brake pedal, measure the voltage between the trailer tow connector pin 1, circuit CAT06 (YE), component side and ground.
- Is the voltage greater than 10 volts?
Yes
The vehicle is operating correctly. SEND the trailer to an authorized camper/trailer repair facility. TEST the system for normal operation.
No
For the 4-pin connector, GO to Z8.
For the 7-pin connector, GO to Z7.
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Z7 CHECK FOR VOLTAGE TO THE TRAILER TOW CONNECTOR (7-PIN)
- Disconnect: Trailer Tow C473.
- While applying the brake pedal, measure the voltage between the trailer tow C473-1, circuit CAT06 (YE), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new trailer tow connector. TEST the system for normal operation.
No
GO to Z8.
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Z8 CHECK CIRCUIT CAT06 (YE) FOR AN OPEN
- Disconnect: SJB C2280a.
- Measure the resistance between the SJB C2280a-14, circuit CAT06 (YE), harness side and the trailer tow C439-2 (4-pin) or C473-1 (7-pin), circuit CAT06 (YE), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to Z9.
No
REPAIR the circuit. TEST the system for normal operation.
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Z9 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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