Pinpoint Test K: The Generic Electronic Module (GEM) Does Not Respond To The Scan Tool

Communications Network

Pinpoint Test K: The Generic Electronic Module (GEM) Does Not Respond To The Scan Tool

Refer to Wiring Diagrams Set 13, Power Distribution for schematic and connector information. Electrical Diagrams

Refer to Wiring Diagrams Set 14, Module Communications Network for schematic and connector information. Electrical Diagrams

Normal Operation

The Generic Electronic Module (GEM) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN).

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- GEM (Generic Electronic Module)

PINPOINT TEST K : THE GEM (Generic Electronic 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.

K1 CHECK THE GEM (Generic Electronic Module) VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: Generic Electronic Module (GEM) C201A.

- Ignition ON.

- Measure the voltage between the GEM (Generic Electronic Module) C201A-10, circuit 15-DK20 (GN/OG), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to K2.

No
VERIFY the Central Junction Box (CJB) fuse 179 (7.5A) is OK. If OK, REPAIR the circuit. 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. Electrical Diagrams

K2 CHECK THE GEM (Generic Electronic Module) GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- Disconnect: GEM (Generic Electronic Module) C201D.

- Measure the resistance between the GEM (Generic Electronic Module) C201D-2, circuit 91-DK20 (BK/RD), harness side and ground.





Is the resistance less than 5 ohms?

Yes
GO to K3.

No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.

K3 CHECK THE MS-CAN (Medium Speed Controller Area Network) CIRCUITS BETWEEN THE GEM (Generic Electronic Module) AND THE DLC (Data Link Connector) FOR AN OPEN

- Disconnect: GEM (Generic Electronic Module) C201B.

- Measure the resistance between the GEM (Generic Electronic Module) C201B-23, circuit 4-EC14 (GY/OG), harness side and the DLC (Data Link Connector) C251-3, circuit 4-EC1 (GY/RD)/4-EC13 (GY/VT)/4-EC14 (GY/OG), harness side.





- Measure the resistance between the GEM (Generic Electronic Module) C201B-22, circuit 5-EC14 (BU/BK), harness side and the DLC (Data Link Connector) C251-11, circuit 5-EC1 (BU/RD)/5-EC13 (BU/WH)/5-EC14 (BU/BK), harness side.





Are the resistances less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to K4.

No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.

K4 CHECK FOR CORRECT GEM (Generic Electronic Module) OPERATION

- Disconnect all GEM (Generic Electronic Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the GEM (Generic Electronic Module) connectors and make sure they seat correctly.

- Verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new GEM (Generic Electronic Module). 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.