PINPOINT TEST AN : The Generic Function Module (GFM) Does Not Respond To The Scan Tool
NOTE:
Failure to disconnect the battery when instructed will result in false resistance readings. REFER to Battery, Mounting and Cables
- AN1 CHECK THE GFM VOLTAGE SUPPLY CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: GFM C2464.
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C2464-1 Ground
Is the voltage greater than 11 volts?
Yes GO to AN2. No VERIFY the BCM fuse 42 (5A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the OEM ELECTRICAL WIRING DIAGRAM INTRODUCTION to identify the possible causes of the circuit short. - AN2 CHECK THE GFM GROUND CIRCUITS FOR AN OPEN
- Ignition OFF.
- Measure:
Positive Lead Measurement / Action Negative Lead C2464-14 Ground
Is the resistance less than 3 ohms?
Yes GO to AN3. No REPAIR the circuit. - AN3 CHECK THE HS-CAN CIRCUITS BETWEEN THE GFM AND THE DLC FOR AN OPEN
Are the resistances less than 3 ohms?
Yes CONNECT the negative battery cable. GO to AN4. No REPAIR the circuit in question. - AN4 CHECK FOR CORRECT GFM OPERATION
- Ignition OFF.
- Disconnect and inspect the GFM connector and related in-line connectors.
- Repair:
- corrosion (replace connector or terminals - clean module pins)
- damaged or bent pins - replace terminals/pins
- pushed-out pins - replace pins as necessary
- Reconnect the GFM connector and related in-line connectors. Make sure they seat and latch correctly.
- Operate the system and verify the concern is still present
Is the concern still present?
Yes CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, discontinue this test and follow TSB instructions. If no TSBs address this concern, INSTALL a new GFM. REFER to Police Package Equipment . No The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
