Pinpoint Test Q: DTC P1601, U0115
WARNING: This page is about a different variant/trim than selected.
- Refer to MODULE COMMUNICATIONS NETWORK
for schematic and connector information.
Normal Operation and Fault Conditions
The TCM and the PCM communicate through messages sent on HS-CAN1 and on a dedicated transmission CAN. The HS-CAN1 and transmission CAN messages are not redundant, so both CAN buses must be operational for proper transmission control.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition TCM P1601:00 ECM/TCM Serial Communication Error: No Sub Type Information The TCM sets this DTC if the PCM is communicating over HS-CAN and the transmission CAN, but is reporting faults in key signals. TCM U0115:00 Lost Communication With ECM/PCM 'B': No Sub Type Information The TCM sets this DTC if powertrain data messages received from the PCM over the HS-CAN or the transmission CAN are missing for longer than 5 seconds. Possible Sources
- Communication concern
- Circuit open or shorted
- PCM
- TCM
Visual Inspection and Pre-checks
- Some aftermarket PCM tuner software may result in the PCM broadcasting engine operating values that exceed the TCM expected calibrated range for those parameters. The TCM will store a P1601:00 when this occurs.
- Q1 CHECK THE TCM (TRANSMISSION CONTROL MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, retrieve all diagnostic trouble codes (DTCs) from the TCM.
Is DTC P1601 and/or U0115 present?
Yes If diagnostic trouble codes (DTCs) U0103, U0121, U0140 and U0155 are all also present, indicating the HS-CAN bus is down, GO to Pinpoint Test U Otherwise, GO to Q2 No The system is operating correctly at this time. The DTC may have been set due to high network traffic or an intermittent fault condition. - Q2 VERIFY THE SCAN TOOL COMMUNICATES WITH THE PCM (POWERTRAIN CONTROL MODULE)
- Ignition ON.
- Using a diagnostic scan tool, carry out the KOEO PCM self-test.
Did the PCM complete the self-test?
Yes GO to Q3 No To diagnose a PCM does not respond to the scan tool concern, REFER to: Communications Network - Q3 CHECK THE PCM (POWERTRAIN CONTROL MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, carry out the KOEO and KOER PCM self-tests.
Are any diagnostic trouble codes (DTCs) present in the PCM?
Yes RESOLVE all PCM diagnostic trouble codes (DTCs) first. REFER to: Electronic Engine Controls No GO to Q4 - Q4 CHECK THE TRANSMISSION CAN (CONTROLLER AREA NETWORK) CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect TCM C1750A .
- Disconnect PCM C1232T .
- Disconnect GSM C2532 .
- Disconnect Mode select switch C284 .
- Inspect the connectors for damaged or pushed-out terminals.
- Measure:
Positive Lead Measurement / Action Negative Lead C1750A-44 C1232T-23 C1750A-45 C1232T-8 C1750A-44 C2532-13 C1750A-45 C2532-14 C1750A-44 C284-4 C1750A-45 C284-3
Are the resistances less than 3 ohms?
Yes GO to Q5 No REPAIR the circuit. - Q5 CHECK THE TRANSMISSION CAN (CONTROLLER AREA NETWORK) CIRCUITS FOR A SHORT TO GROUND
Are the resistances greater than 10, 000 ohms?
Yes Connect all connectors that have been disconnected. GO to Q6 No REPAIR the circuit. - Q6 CHECK THE TCM (TRANSMISSION CONTROL MODULE) FOR DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, clear all diagnostic trouble codes (DTCs) from the TCM.
- Road test the vehicle.
- Using a diagnostic scan tool, carry out the TCM self-test.
Is DTC P1601 and/or U0115 still present?
Yes If any TCM voltage supply or internal module diagnostic trouble codes (DTCs) are present, RESOLVE those first. REFER to the Diagnostic Trouble Code (DTC) Chart . Otherwise, GO to Q7 No The system is operating correctly at this time. The DTC may have been set due to high network traffic, or by a connector or pin issue. - Q7 CHECK FOR PCM (POWERTRAIN CONTROL MODULE) COMMUNICATION DIAGNOSTIC TROUBLE CODES (DTCS) SET IN OTHER MODULES
- Using a diagnostic scan tool, retrieve all continuous memory diagnostic trouble codes (CMDTCs) from all modules.
Are PCM communication diagnostic trouble codes (DTCs) present in other modules?
Yes GO to Q8 No GO to Q9 - Q8 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all PCM and related inline 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 PCM and all related inline 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 PCM. Refer to Powertrain Control Module (PCM) . No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues. - Q9 CHECK FOR CORRECT TCM (TRANSMISSION CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all TCM and all related inline 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 and all related inline 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 TCM. REFER to: Transmission Control Module (TCM) No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.