Mariner 4WD L4-2.5L (2010)
Normal Operation
The Battery Junction Box (BJB) fuse 14 (15A) supplies voltage to the LH and RH trailer tow stop/turn relays.
The trailer tow LH stop/turn relay coil receives voltage when the vehicle LH rear stoplamp is illuminated. When the trailer tow LH stop/turn relay is
energized, voltage is routed to the trailer tow connector.
The trailer tow RH stop/turn relay coil receives voltage when the vehicle RH rear stoplamp is illuminated. When the trailer tow RH stop/turn relay is
energized, voltage is routed to the trailer tow connector.
This pinpoint test is intended to diagnose the following:
-
Fuse
-
Wiring, terminals or connectors
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Trailer tow stop/turn relay
-
Trailer
PINPOINT TEST Z: THE TRAILER STOP/TURN LAMP IS 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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Z1 CHECK FOR VOLTAGE THROUGH THE TRAILER TOW CONNECTOR
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Ignition OFF.
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Disconnect: Trailer Tow C439.
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For the LH trailer stop/turn lamp, while applying the brake pedal, measure the voltage between the trailer tow C439-2, circuit CAT06 (YE),
harness side and ground.
-
For the RH trailer stop/turn lamp, while applying the brake pedal, measure the voltage between the trailer tow C439-1, circuit CAT09 (GN),
harness 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.
No
GO to Z2.
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Z2 CHECK THE TRAILER TOW STOP/TURN RELAY
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Disconnect: Suspect Trailer Tow Stop/Turn Relay.
-
Substitute a know good relay.
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For the LH trailer stop/turn lamp, while applying the brake pedal, measure the voltage between the trailer tow C439-2, circuit CAT06 (YE),
harness side and ground.
