P2D28: Cold Start Propulsion Torque Performance

What it means

During cold start, the propulsion torque output does not match the calibrated cold-start torque profile. Cold engine response, hybrid blend, or torque modelling deviates from expected.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

During a cold start, the control module estimates propulsion torque from the engine and, in a hybrid, the combined engine and electric drive response. P2D28 sets when measured or modelled torque does not follow the expected cold-start profile, which can reflect excess engine drag or an off-target hybrid torque blend.

Common causes

Most likely first.

1. Increased cold-engine drag torque
2. Hybrid blend strategy off-target

Symptoms

• Check-engine light
• Sluggish response after a cold start
• Reduced power while the engine is cold

How to diagnose it

1. Record freeze-frame data and note engine temperature, ambient temperature, and vehicle state when the cold-start fault occurred.
2. Compare requested and delivered torque data from a scan tool during a cold start, including the engine and hybrid torque contributions if available.
3. Check for related engine, transmission, or hybrid-system codes that could explain excess drag or an incorrect torque estimate.
4. Inspect for obvious mechanical drag, fluid leaks, or abnormal noises that occur while the engine is cold.
5. If no related fault is found, compare cold-start torque data with the manufacturer's diagnostic criteria to evaluate torque modelling and hybrid blending.

Common fixes

• Repair an underlying engine or drivetrain fault causing excess drag during cold operation.
• Correct a detected sensor or wiring fault that is distorting torque data.
• Repair a hybrid control or torque-blending fault if diagnosis identifies one.
• Clear the code and confirm cold-start response and torque tracking are normal.

Can I keep driving?

If the vehicle remains controllable, drive gently while the engine is cold and avoid merging into fast traffic until response improves. Stop if power loss becomes severe or another propulsion warning appears.