Thermal protection functions reduce engine output when critical temperatures exceed safe thresholds. This protects pistons, turbochargers, exhaust manifolds, catalysts, and other heat-sensitive components from damage.

Vue d'ensemble

The ECU monitors multiple temperature inputs and applies torque derating when limits approach. Protection may be gradual (progressive reduction) or immediate (limp mode) depending on severity.

Monitored Temperatures

• Coolant temperature
• Oil temperature
• Température de l'air d'admission
• Température des gaz d'échappement (EGT)
• Turbo inlet/outlet temperature
• Catalyst temperature (modeled)

Maps Involved

• Temperature Threshold Maps
• Torque Derating Maps vs temperature
• EGT Protection Maps
• Fan Control Maps

Logic Sequence

Temperature Inputs → Compare to Thresholds
         ↓
If approaching limit → Begin torque reduction
         ↓
Activate cooling (fans, enrichment)
         ↓
If critical → Limp mode / warning light
         ↓
Monitor for recovery

Calibration Objectives

• Prevent thermal damage to engine/turbo
• Allow recovery without shutdown when possible
• Provide driver feedback

Calibration Strategy

• Raise thresholds only if cooling is upgraded
• Monitor actual temperatures during extended WOT
• Consider ambient conditions

Diagnostics

• Overtemperature DTCs
• Frequent thermal derating
• Cooling system faults

Best Practices

• Thermal protection exists for good reason — respect it
• Upgrade cooling before raising thermal limits
• Data log temperatures during performance testing