Code
C1276
HUMMER
C — Chassis
Delivered Torque Signal Circuit Malfunction
AI status
Completed
Completed
100%
Causes
- Damaged, chafed, or pinched wiring in the delivered torque signal circuit
- Corroded, loose, or contaminated connector at sensor/module
- Open or short to ground/power in the harness
- Faulty torque sensor, torque request module, or delivering control module
- Blown fuse or poor power/ground to the controlling module
- Intermittent connection due to vibration or water intrusion
Symptoms
- Malfunction Indicator Light (MIL) or ABS/Traction/Stability warning lamp illuminates
- Reduced traction/stability control function or limited drivability
- Unexpected torque reduction or limp/limited power mode
- Intermittent faults or drivability complaints under load
- Related modules may log additional communication or torque-related faults
What to check
- Read all stored/active codes and freeze frame data with a capable scan tool
- Check for related U‑codes (loss of communications) that may indicate module issues
- Visually inspect wiring and connectors along the delivered torque signal circuit for damage, corrosion, or loose pins
- Inspect module power and ground circuits and verify corresponding fuses
- Backprobe the signal connector and monitor live data while operating the vehicle (or simulating torque request)
- Wiggle test wiring while monitoring signal to reproduce intermittent faults
Signal parameters
- Signal type: typically a low voltage analog or pulse (PWM) torque/discrete signal from a torque/torque-request sensor or module
- Reference voltage: usually derived from module reference (commonly ~5 V); confirm with factory data
- Idle/nominal signal: will show a steady voltage or duty cycle that changes with torque request; should not be open or hard shorted to battery/ground
- Short to ground: signal reads ~0 V; short to battery: signal reads near battery voltage; open circuit: no continuity
- For accurate expected voltage, duty cycle, or frequency values, consult OEM wiring diagrams and service specifications
Diagnostic algorithm
- Retrieve all DTCs and freeze frame data. Note module(s) reporting the C1276 and any related U or C codes.
- Visually inspect connectors and wiring on the torque signal sender, related control modules, and harness routing for damage, corrosion, or water intrusion. Repair or replace as needed.
- Verify power and ground to the sending and receiving modules; check fuses and relays. Repair bad power/grounds before further testing.
- Backprobe the delivered torque signal connector with a multimeter or oscilloscope. With key ON (engine off) and while operating the torque input (or performing a controlled test), observe voltage/duty cycle changes and compare to factory data.
- Check continuity between the sender and the receiving module. Look for shorts to battery and ground. Repair any found wiring faults (repair, splice, or replace harness section).
- If wiring and connectors are good, test/replace the torque sensor or sending module per OEM procedures.
- If replacing modules, perform any required module programming or relearn procedures.
- Clear codes and perform a road test to confirm the fault does not return and that related systems operate normally.
- If intermittent or communication errors persist, capture live data and consider component swap diagnostics or consult OEM technical service information.
Likely causes
- Wiring harness damage at steering column, transfer case, or steering angle/torque sensor location
- Corroded connector pin at the torque signal sender or receiving module
- Failed torque sensor or delivering control module
- Loss of reference voltage or ground to the module
Fault status
Status
Delivered Torque Signal Circuit malfunction detected. Electrical fault (open/short/out-of-range) on delivered torque signal.
Repair difficulty: Medium
Diagnostic time: 1.0 - 2.5 hours
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