Upfitter Relay Box
Upfitter Relay Box
Pinpoint Tests
Pinpoint Test J: The Customer Access System Does Not Operate Correctly
Refer to Wiring Diagram Set 140, Customer Access for schematic and connector information. Diagrams By Number
Normal Operations
With the ignition key in the ON position, voltage is supplied to the upfitter control switches through circuit CBP42. Voltage is supplied to the switched side of the upfitter relays on circuit SBB07 (upfitter relay No. 1), SBB08 (upfitter relay No. 2), SBP14 (upfitter relay No. 3) or SBP16 (upfitter relay No. 4). When a control switch is closed it supplies voltage to 1 of the 4 upfitter relays through circuit CAC01 (upfitter relay No. 1), CAC02 (upfitter relay No. 2), CAC03 (upfitter relay No. 3) or CAC04 (upfitter relay No. 4) closing the upfitter relay. When the relay closes, voltage is supplied through the relay to the output circuit (to the blunt cut ends) CAC05 (upfitter relay No. 1), CAC06 (upfitter relay No. 2), CAC07 (upfitter relay No. 3) or CAC08 (upfitter relay No. 4).
This pinpoint is intended to diagnose the following:
- Fuse(s)
- Upfitter relay(s)
- Upfitter relay switch(es)
- Wiring, terminals or connectors
- Upfitter relay box
- Smart Junction Box (SJB)
- Battery Junction Box (BJB)
PINPOINT TEST J: THE CUSTOMER ACCESS SYSTEM DOES NOT OPERATE CORRECTLY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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J1 CHECK THE UPFITTER SYSTEM
- Operate all the upfitter accessories.
- Are all the upfitter accessories inoperative?
Yes
VERIFY the SJB fuse 42 (10A) is OK. If OK, GO to J4. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the short circuit. Diagrams By Number
No
GO to J2.
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J2 CHECK THE UPFITTER RELAY GROUND CIRCUITS
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Disconnect: Upfitter Relay 1 C2301, Relay 2 C2302, Relay 3 C2303, Relay 4 C2304.
- Measure the resistance between the upfitter relay box, harness side and ground as follows:
- Are the resistances less than 5 ohms?
Yes
CONNECT the negative battery cable. GO to J3.
No
REPAIR the circuit. CONNECT the negative battery cable. TEST the system for normal operation.
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J3 CHECK THE UPFITTER SWITCHES FOR SWITCH VOLTAGE
- Disconnect: Upfitter Switches C2300.
- Ignition ON.
- Measure the voltage between the upfitter switches C2300-8, circuit CBP42 (GN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to J4.
No
REPAIR the circuit. TEST the system for normal operation.
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J4 CHECK THE UPFITTER SWITCH OPERATION
- Connect: Upfitter Switches C2300.
- Turn all the upfitter switches to the ON position.
- Measure the voltage between the upfitter relay control circuits, harness side and ground as follows:
- Are the voltages greater than 10 volts?
Yes
GO to J6.
No
GO to J5.
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J5 CHECK THE RESISTANCE BETWEEN THE UPFITTER RELAYS AND THE UPFITTER SWITCHES
- Ignition OFF.
- Disconnect: Upfitter Switches C2300.
- Measure the resistance between the upfitter relay, harness side and the upfitter switch C2300, harness side as follows.
- Are all the resistances less than 5 ohms?
Yes
INSTALL a new upfitter switch. REFER to Upfitter Switch Upfitter Switch.
No
REPAIR the suspect circuit. TEST the system for normal operation
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J6 CHECK THE UPFITTER RELAY VOLTAGE SUPPLY CIRCUITS FOR AN OPEN
- Measure the voltage between the upfitter relay, harness side and ground as follows:
- Are all the voltages greater than 10 volts?
Yes
GO to J7.
No
VERIFY the BJB fuses 7 (30A), 8 (30A); and SJB fuses 14 (10A), 16 (15A) are OK. If OK, REPAIR the suspect circuit.
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J7 CHECK THE UPFITTER RELAY
- Carry out the upfitter relay component test.
- Does the upfitter relay pass the component test?
Yes
GO to J8.
No
INSTALL a new upfitter relay. TEST the system for normal operation.
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J8 CHECK THE UPFITTER RELAY OUTPUT CIRCUITS
- Connect: Upfitter Relay C2301, C2302, C2303, C2304.
- Turn the upfitter switches on.
- Measure the voltage between the upfitter relay box output circuits, at the blunt cut ends and ground as follows:
- Are the voltages greater than 10 volts?
Yes
The system is operating correctly at this time. DIAGNOSE the add-on accessory as necessary.
No
REPAIR or INSTALL a new upfitter relay box as necessary. REFER to Upfitter Relay Box Upfitter Relay Box. TEST the system for normal operation.
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