Code
P1336
ALFA ROMEO
P — Powertrain
Torque control request fault
Views:
UK: 4
EN: 11
RU: 9
AI status
Completed
Completed
100%
Causes
- Faulty wiring, connectors or grounds between engine ECU and transmission/torque-control module
- CAN bus or serial communication errors between control modules
- Faulty engine control module (ECU) or transmission control module (TCM)
- Corroded or damaged connectors or pin corrosion
- Low / unstable battery or charging system voltage
- Software/calibration error or corrupted module firmware
Symptoms
- Malfunction Indicator Lamp (MIL) or warning light illuminated
- Engine in limp/reduced power mode
- Reduced or inconsistent engine torque delivery
- Transmission shifting problems or torque converter not responding correctly
- Loss of driveability, hesitation or unexpected torque cut
- Stored communication or torque-related diagnostic trouble codes
What to check
- Read and record all stored DTCs and freeze-frame data with a capable scan tool (read both engine and transmission modules)
- Check battery voltage and charging system (measure at rest and cranking)
- Visually inspect wiring, connectors and grounds between ECU and TCM for damage or corrosion
- Check CAN-bus health: termination, voltage levels and continuity
- Monitor live data: torque request vs actual torque, throttle and pedal sensors, module comm status
- Wiggle-testing harness while monitoring live data to reproduce interrupts
Signal parameters
- Torque_request (Nm) — commanded torque from master module
- Engine_torque_actual (Nm) — measured/estimated engine torque
- Accelerator_pedal_position (%)
- Throttle_position (%) / throttle valve angle
- Torque_limit / torque_reduction flags
- CAN bus error counters and node alive messages
Diagnostic algorithm
- Connect full-function scan tool, record all codes in engine and transmission modules, save freeze frame and live data. Clear codes and attempt to reproduce.
- If the code returns, note conditions (rpm, load, temperature) from freeze frame and live data.
- Verify battery voltage and charging system. Repair charging/voltage issues before continuing.
- Visually inspect and backprob wiring and connectors between ECU and torque-management/TCM. Repair any damage or corrosion.
- Check CAN/comm lines for proper termination, ±2.5V idle, and no short to power/ground. Use scope or CAN tester if available.
- Monitor torque_request and related signals while operating or road-testing to identify missing or invalid messages. Wiggle harnesses to find intermittent faults.
- Test related input sensors (throttle, pedal position) for correct voltages and operation per manufacturer specs.
- If wiring and sensors are good, perform module communication tests. Reflash or update ECU/TCM software if a known update is available.
- If fault persists after wiring and software checks, consider module swap or bench test of suspect module (follow manufacturer procedures) or refer to dealer-level diagnostics.
- After repair, clear codes and perform a road test to confirm the fault does not return.
Likely causes
- Intermittent CAN/communication wiring fault between ECU and torque-management module
- Corroded connector at ECU or TCM causing missing signal
- Faulty accelerator pedal or throttle position sensor giving invalid torque request inputs
- Low battery/charging system causing corrupted module communication
- Software bug or need for ECU/TCM reflash
Fault status
Status
Torque control request signal invalid or missing — communication/signal fault detected by powertrain control module.
Repair difficulty: Medium
Diagnostic time: 1.5-4.0 hours
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