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Home >> Chevrolet >> 2001 >> Impala Base, 3.8 K >> Repair and Diagnosis >> External Pages >> Different car >> Section 36 (HVAC Systems - Automatic) >> Diagnostic Tests >> DTC B0441: Left-Side Temperature Actuator Shorted Or Open >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue. However, it is still accessible from the selected car via links, so may be relevant.
  1. If diagnostic system check was not performed, go to DIAGNOSTIC SYSTEM CHECK . If diagnostic system check was performed, go to next step.
  2. Install scan tool. Turn ignition on. Using scan tool, command LEFT MIX MOTOR ON and OFF to display maximum and minimum counts of LH MIX MOTOR POSITION FEEDBACK in HEATING and AIR CONDITIONING, SPECIAL FUNCTIONS, MISCELLANEOUS TEST list. Subtract minimum LH MIX MOTOR POSITION FEEDBACK from maximum LH MIX MOTOR POSITION FEEDBACK. If calculation indicates actual travel of left air temperature actuator is within 147-251 counts, problem is intermittent. If calculation does not indicate actual travel of left air temperature actuator is within 147-251 counts, go to next step.
  3. Check ignition voltage circuit of left air temperature actuator for an open circuit or high resistance. Repair wiring as necessary. If wiring is okay, go to next step.
  4. Check left air temperature door control circuit of left air temperature actuator for an open, high resistance, short to ground or short to voltage. Repair wiring as necessary. If wiring is okay, go to next step.
  5. Check 5-volt reference circuit at left air temperature actuator for an open or high resistance. Repair wiring as necessary. If wiring is okay, go to next step.
  6. Ensure HVAC control module and left air temperature actuator connectors are connected. Turn ignition on. Using scan tool, observe LH MIX MOTOR POSITION FEEDBACK data parameter. Connect 3-amp fused jumper wire between left air temperature door control circuit and 5-volt reference circuit of left air temperature actuator (drives actuator to full HOT). Remove and reconnect jumper wire between left air temperature door control circuit and ground circuit of left air temperature actuator (drives actuator to full COOL). If left air temperature actuator drive shaft rotates and counts change, go to next step. If left air temperature actuator drive shaft does not rotate and counts do not change, go to step  9.
  7. Measure voltage between left air temperature door control circuit of left air temperature actuator and ground. Using scan tool, command LEFT TEMP DOOR POSITION from HOT to COLD. If voltage measures near 5 volts when increasing temperature, near zero volts when decreasing temperature and near 2.5 volts when stationary, go to next step. If voltage does not measure near 5 volts when increasing temperature, near zero volts when decreasing temperature and near 2.5 volts when stationary, go to step  10.
  8. Check left air temperature door and left air temperature actuator for misaligned air temperature actuator, broken or binding linkages, obstruction, missing or misaligned seals.
  9. Check for poor connection at harness connector of left air temperature actuator. Repair connector as necessary, then go to step  13. If connector is okay, go to step  11.
  10. Check for poor connection at harness connector of HVAC control module. Repair connector as necessary, then go to step  13. If connector is okay, go to step  12.
  11. Replace left air temperature actuator. See TEMPERATURE ACTUATORS  under REMOVAL & INSTALLATION. After repairs are complete, go to step  13.
  12. Replace HVAC control module. See HVAC CONTROL MODULE  under REMOVAL & INSTALLATION. After repairs are complete, go to next step.
  13. Clear DTCs. Operate vehicle. Check for DTCs. If DTC B0441 is still present, go to step  2. If DTC does not reset, system is okay.
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