PINPOINT TEST AB : The TCM 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
- AB1 CHECK THE TCM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: TCM.
- Ignition ON.
- Measure:
Positive Lead Measurement / Action Negative Lead C1750-1 Ground C1750-31 Ground C1750-33 Ground
Is the voltage greater than 11 volts?
Yes GO to AB2. No VERIFY the BJB fuse 56 (15A) and 90 (10A) are 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. - AB2 CHECK THE TCM GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure:
Positive Lead Measurement / Action Negative Lead C1750-9 Ground C1750-39 Ground C1750-41 Ground
Is the resistance less than 3 ohms?
Yes GO to AB3. No REPAIR the circuit. - AB3 CHECK THE HS-CAN CIRCUITS BETWEEN THE TCM AND THE DLC FOR AN OPEN
Are the resistances less than 3 ohms?
Yes CONNECT the negative battery cable. GO to AB4 No REPAIR the circuit in question. - AB4 CHECK FOR CORRECT TCM OPERATION
- Ignition OFF.
- Disconnect and inspect the TCM connector and related in-line connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the TCM connector and related in-line connectors. Make sure they seat and latch correctly.
- Operate the system and determine the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable TSBs. If a TSB DISCONTINUE this test and FOLLOW TSB instructions. If no TSBs address this concern, INSTALL a new TCM. REFER to Automatic Transmission 6F35 . No The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
