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Home >> Cadillac >> 1998 >> Seville STS >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Module >> Diagnosis & Testing >> DTC B1310: Outside (Ambient) Air Temperature Sensor Failure >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  . After performing system check, go to next step.
  2. Turn ignition off. Disconnect outside air temperature sensor, located in center front of vehicle, near hood latch. Check resistance between sensor terminals "A" (Dark Green wire) and "B" (Brown wire). Compare resistance reading to TEMPERATURE-TO-RESISTANCE VALUES  table. If resistance is as specified, go to next step. If resistance is not as specified, go to step 6).
  3. Turn ignition on. Check voltage between sensor harness connector terminals "A" (Dark Green wire) and "B" (Brown wire). See WIRING DIAGRAMS  . If voltage reading is 5 volts, go to next step. If voltage reading is not 5 volts, go to step 7).
  4. Turn ignition off. Reconnect sensor connector. Turn ignition on. Using scan tool, clear DTCs. Cycle ignition switch on then off several times. Check DTCs. If DTC resets, go to next step. If DTC does not reset, problem is intermittent. Check for intermittent or poor connection.
  5. Replace IPM. After replacing IPM, go to step 13).
  6. Replace outside (ambient) temperature sensor. After replacing sensor, go to step 13).
  7. Check voltage between ground and sensor terminal "A" (Dark Green wire). If voltage reading is 5 volts, go to next step. If voltage reading is not 5 volts, go to step 10).
  8. Check if HVAC related DTCs are set. If HVAC DTCs are set, go to next step. If no HVAC DTCs are set, go to step 12).
  9. Check for open in Yellow wire between sensor terminal "D" and IPM harness connector terminal B8. If circuit is open, repair as necessary. After repairs, go to step 13). If circuit is okay, replace IPM.
  10. Check voltage between ground and IPM harness connector terminal B1 (Light Green/Black wire). If voltage reading is 5 volts, go to next step. If voltage reading is not 5 volts, go to step 5).
  11. Repair open in Light Green/Black wire between IPM connector terminal B1 and HVAC control panel. After repairs, go to step 13).
  12. Repair open in Yellow wire between IPM connector terminal B8 and sensor terminal "D". After repairs, go to next step.
  13. Clear DTCs. Recheck for proper A/C system operation.
TEMPERATURE-TO-RESISTANCE VALUES

°F (°C) Min/Max (K/ohms)
14 (-10) 5.27/5.98
23 (-5) 4.03/4.52
32 3.11/3.44
41 2.43/2.66
50 1.91/2.07
59 1.51/1.62
58 1.21/1.28
77 0.97/1.02
86 0.78/0.82
95 0.63/0.67
104 0.51/0.55
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