Low Heat Output From Front and Rear Heaters at Low Speeds

Tests 1 - 2:

Tests 3 - 4:

SYMPTOM
LOW HEAT OUTPUT FROM FRONT AND REAR HEATERS AT LOW SPEEDS

POSSIBLE CAUSES
- Check front and rear heaters performance
- Rear heater coolant pump ground circuit open
- Rear heater coolant pump
- Rear heater coolant pump driver circuit open
- A/C - heater control module