Pinpoint Test F: The Four Wheel Drive (4X4) Control Module Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2008 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Module Communications Network for schematic and connector information.

Refer to appropriate SYSTEM WIRING DIAGRAMS article, All Wheel Drive System for schematic and connector information.

Normal Operation

The 4X4 control module communicates with the scan tool through the high speed controller area network (HS-CAN). Circuits VDB04 (WH/BU) (HS-CAN +) and VDB05 (WH) (HS-CAN -) provide the network connection to the 4X4 control module. The 4X4 control module shares the HS-CAN with the PCM, the restraints control module (RCM), the occupant classification system module (OCSM), the instrument cluster (IC), and the SJB. Voltage is supplied by circuits SBB27 (BU/RD), SBP28 (GN/RD) and CBP10 (YE/OG). Ground is supplied by circuits GD161 (BK/YE) and GD174 (BK/WH).

This pinpoint test is intended to diagnose the following:

Fuse
Wiring, terminals or connectors
4X4 control module

PINPOINT TEST F: THE FOUR WHEEL DRIVE (4X4) CONTROL MODULE DOES NOT RESPOND TO THE SCAN TOOL

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

F1 CHECK THE 4X4 CONTROL MODULE VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

Key in OFF position.
Disconnect: 4X4 Control Module C281a
Disconnect: 4X4 Control Module C281b
Key in ON position.

Measure the voltage between the 4X4 control module, harness side and ground as follows:

Connector-Pin	Circuit
C2281-8	CBP10 (YE/OG)
C2281-6	SBB27 (BU/RD)
C2281-7	SBP28 (GN/RD)

Are the voltages greater than 10 volts?

YES : Go to F2.
NO : VERIFY the battery junction box (BJB) fuse 27 (20A), and SJB fuses 10 (10A) and 28 (15A) are OK. If OK, REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.

F2 CHECK THE 4X4 CONTROL MODULE GROUND CIRCUITS FOR AN OPEN

Key in OFF position.
Disconnect: IC C220a

Measure the resistance between the 4X4 control module, harness side and ground as follows:

Connector-Pin	Circuit
C2281-10	GD161 (BK/YE)
C2281-3	GD174 (BK/WH)

Are the resistances less than 5 ohms?

YES : Go to F3.
NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.

F3 CHECK THE HIGH SPEED CAN CIRCUITS BETWEEN THE DATA LINK CONNECTOR (DLC) AND THE 4X4 CONTROL MODULE FOR AN OPEN
- Measure the resistance between the 4X4 control module C281a-10, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.
- Measure the resistance between the 4X4 control module C281a-9, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
- Are the resistances less than 5 ohms?
1. YES : Go to F4.
2. NO : REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.
F4 CHECK FOR CORRECT 4X4 CONTROL MODULE OPERATION
- Disconnect all the 4X4 control module connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the 4X4 control module connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a 4X4 control module. REFER to FOUR WHEEL DRIVE (4WD) SYSTEMS article. CLEAR the DTCs. REPEAT the network test with the scan tool.
2. 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 network test with the scan tool.