Pinpoint Test Q: No ISO 9141 Communication Or The 4X4 Control Module Does Not Respond To The Scan Tool
Communications Network
Pinpoint Tests
Pinpoint Test Q: No ISO 9141 Communication Or The 4X4 Control Module Does Not Respond To The Scan Tool
Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 34, Four Wheel Drive Systems for schematic and connector information. Diagrams By Number
Normal Operation
The 4X4 control module communicates with the scan tool through the ISO 9141 communications network.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- 4X4 control module
PINPOINT TEST Q: NO ISO 9141 COMMUNICATION OR THE 4X4 CONTROL MODULE DOES NOT RESPOND TO THE SCAN TOOL
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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Q1 CHECK THE DLC PINS FOR DAMAGE
- Ignition OFF.
- Disconnect the scan tool cable from the DLC.
- Inspect the Data Link Connector (DLC) pin 7 for damage.
- Is the DLC pin 7 OK?
Yes
GO to Q2.
No
REPAIR the DLC as necessary. CLEAR the DTCs. REPEAT the network test with the scan tool.
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Q2 CHECK THE ISO 9141 CIRCUIT FOR A SHORT TO GROUND
- Disconnect: Negative Battery Cable.
- Disconnect: 4X4 Control Module C281a.
- Measure the resistance between the DLC C251-7, circuit VDB10 (GY), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to Q3.
No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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Q3 CHECK THE ISO 9141 CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between the DLC C251-7, circuit VDB10 (GY), harness side and ground.
- Is any voltage present?
Yes
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
GO to Q4.
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Q4 CHECK VDB10 (GY) FOR AN OPEN BETWEEN THE 4X4 CONTROL MODULE AND THE DLC
- Ignition OFF.
- Measure the resistance between the 4X4 control module C281a-10, circuit VDB10 (GY), harness side and the DLC C251-7, circuit VDB10 (GY), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to Q5.
No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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Q5 CHECK THE 4X4 CONTROL MODULE VOLTAGE SUPPLY CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: 4X4 Control Module C281b.
- Ignition ON.
- Measure the voltage between the 4X4 control module, harness side and ground as follows:
- Are the voltages at each pin greater than 10 volts?
Yes
GO to Q6.
No
VERIFY the Smart Junction Box (SJB) fuses 35 (10A), 40 (20A) and 43 (10A) are OK. If OK, REPAIR the circuit in question. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the network test with the scan tool. Diagrams By Number
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Q6 CHECK THE 4X4 CONTROL MODULE GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the 4X4 control module C281b-3, GD115 (BK/GY) and ground.
- Is the resistance less than 5 ohms?
Yes
GO to Q7.
No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
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Q7 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?
Yes
INSTALL a new 4X4 control module. REFER to Transfer Case. CLEAR the DTCs. REPEAT the network test with the scan tool.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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