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DTC B0237: Left Temperature Actuator

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: The numbers below refer to the step numbers of the diagnostic procedure.
  1. 4  - Tests for the proper operation of the circuit in the high voltage range.
  2. 5  - Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
  3. 6  - Tests for a short to ground in the 5 volt reference circuit.
  1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing system check, go to next step.
  2. Connect scan tool. Turn ignition on. Using scan tool, observe LEFT TEMP DR ACTUAL parameter in INSTRUMENT PANEL MODULE HVAC DOOR POSITIONS data list. If scan tool indicates LEFT TEMP DR ACTUAL parameter is 0.05-4.9 volts, inspect wiring and connectors for intermittent loose wires and/or poor connections. Also check for a damaged or broken air temperature door and or actuator. If scan tool indicates LEFT TEMP DR ACTUAL parameter is not 0.05-4.9 volts, go to next step.
  3. Use scan tool to change LEFT TEMP DOOR POSITION from HOT to COLD. Using scan tool, observe LEFT TEMP DR ACTUAL parameter in INSTRUMENT PANEL MODULE HVAC DOOR POSITIONS data list. If scan tool indicates LEFT TEMP DR ACTUAL parameter in INSTRUMENT PANEL changes when LEFT TEMP DR is moved from hot to cold, inspect left air temperature door actuator for a condition allowing excessive travel, if air temperature door actuator is okay, check for loose wires and/or poor connections at left air actuator. If wiring and connectors are okay, replace left air temperature door actuator. See AIR TEMPERATURE DOOR ACTUATORS  under REMOVAL & INSTALLATION. Go to step  9. If scan tool indicates LEFT TEMP DR ACTUAL parameter in INSTRUMENT PANEL does not change when LEFT TEMP DR is moved from hot to cold, go to next step.
  4. Turn ignition off. Disconnect left air temperature door actuator. Turn ignition on. Using scan tool, observe LEFT TEMP DR ACTUAL parameter. If scan tool indicates LEFT TEMP DR ACTUAL parameter is more than 4.9 volts, go to next step. If LEFT TEMP DR ACTUAL parameter is 4.9 volts or less, check for short to ground between ground and terminal No. 9 (Light Blue wire) of left air temperature door actuator harness connector. If short to ground is found, repair Light Blue wire between left air temperature door actuator and terminal A5 of Instrument Panel Module (IPM). Go to step  9. If short to ground was not found, inspect for poor connections at IPM module. If poor connections are found, repair as needed and go to step  9. If connections are okay, replace IPM. See INSTRUMENT PANEL MODULE (IPM)  under REMOVAL & INSTALLATION. Recalibrate IPM. Go to step  9.
  5. Turn ignition off. Connect a 3-amp. jumper wire between terminals No. 9 (Light Blue wire) and No. 7 (Yellow wire) of left air temperature door actuator harness connector. See Figure. Turn ignition on. Using scan tool, observe LEFT TEMP DR ACTUAL parameter. If scan tool indicates LEFT TEMP DR ACTUAL parameter is 0.05 volts or less, go to next step. If scan tool indicates LEFT TEMP DR ACTUAL parameter is more than 0.05 volts, check for short to voltage, open or high resistance between ground and terminal No. 9 (Light Blue wire) of left air temperature door actuator harness connector. Repair as necessary and go to step  9. If circuit is okay, check for open or high resistance in Yellow wire between terminal No. 7 of left air temperature door actuator and terminal A7 of IPM. Repair as necessary and go to step  9. If circuit is okay, check for loose wires and/or poor connections at IPM. If wiring and connections are okay, replace IPM. See INSTRUMENT PANEL MODULE (IPM)  under REMOVAL & INSTALLATION. Go to step  9.
  6. Turn ignition off. Disconnect fused jumper wire. Reconnect jumper wire between terminal No. 6 (Dark Blue wire) and No. 10 (Gray wire) of left air temperature door actuator harness connector. Turn ignition on. Using scan tool, observe LEFT TEMP DR ACTUAL parameter. If scan tool indicates LEFT TEMP DR ACTUAL parameter is more than 4.9 volts, go to step  8. If scan tool indicates LEFT TEMP DR ACTUAL parameter is 4.9 volts or less, go to next step.
  7. Turn ignition off. Check for short to ground between ground and terminal No. 10 (Gray wire) of left air temperature door actuator harness connector. See Figure. Repair as necessary and go to step  9. If circuit is okay, check for loose wires and/or poor connections at Instrument Panel Module (IPM). If wiring and connections are okay, replace IPM. See INSTRUMENT PANEL MODULE (IPM)  under REMOVAL & INSTALLATION. Go to step  9.
  8. Turn ignition off. Check for short to voltage, open or high resistance in Gray wire between ground and terminal No. 10 of left air temperature door actuator harness connector. See Figure. Repair as necessary and go to step  9. If circuit is okay, check for poor connections at actuator harness connector. If wiring and connections are okay, replace mode door actuator. See AIR TEMPERATURE DOOR ACTUATORS  under REMOVAL & INSTALLATION. Go to step  9.
  9. Use scan tool to clear DTCs. Operate vehicle and verify that DTCs do not reset. If DTCs reset, return to step  2. If DTCs do not reset, system is okay.
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