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Home >> Suzuki >> 2007 >> SX4 Base, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 149 (Air Conditioning System) >> Diagnostic Information And Procedures >> DTC B1503: A/C Evaporator Air Temperature Sensor And/Or Its Circuit Malfunction >> DTC Troubleshooting
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DTC Troubleshooting

WARNING: This page is about a different car, the 2007 Suzuki Grand Vitara and 2006 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: When DTC B1502, B1511, B1512 and B1530 are indicated together, it is possible that "BLK/RED" wire circuit open.
DTC TROUBLESHOOTING CHART

Step Action YES NO
Evaporator temperature sensor signal circuit check 
  1. Disconnect evaporator temperature sensor connector with ignition switch turned OFF.
  2. Check for proper connection to evaporator temperature sensor at "WHT/BLK" and "BLK/RED" wire terminals.
  3. If OK, measure voltage between "WHT/BLK" wire terminal of evaporator temperature sensor connector and vehicle body ground with ignition switch turned ON.

Is voltage 4 - 6 V? 
Go to Step 5. Go to Step 2.
Evaporator temperature sensor signal circuit check 
  1. Disconnect connector from HVAC control module with ignition switch turned OFF.
  2. Check for proper connection to HVAC control module connector at "G52-19" and "G52-13" terminals.
  3. If OK, measure resistance between "WHT/BLK" wire terminal of evaporator temperature sensor connector and "G52-19" terminal of HVAC control module connector.

Is resistance below 5 Ω? 
Go to Step 3. "WHT/BLK" wire open or high resistance circuit.
Evaporator temperature sensor signal circuit check 
  1. Measure resistance between "WHT/BLK" wire terminal of evaporator temperature sensor connector and vehicle body ground.

Is resistance infinity? 
Go to Step 4. "WHT/BLK" wire shorted to ground circuit.
Evaporator temperature sensor signal circuit check 
  1. Measure voltage between "WHT/BLK" wire terminal of evaporator temperature sensor connector and vehicle body ground with ignition switch turned ON.

Is voltage 0 V? 
Go to Step 5. "WHT/BLK" wire shorted to other circuit.
Evaporator temperature sensor ground circuit check 
  1. Connect HVAC control module connector with ignition switch turned OFF.
  2. Measure resistance between "BLK/RED" wire terminal of evaporator temperature sensor connector and vehicle body ground.

Is resistance below 5 Ω? 
Go to Step 7. Go to Step 6.
Evaporator temperature sensor ground circuit check 
  1. Measure resistance between "G52-13" terminal of HVAC control module connector and vehicle body ground.

Is resistance below 5 Ω? 
"BLK/RED" wire open or high resistance circuit. HVAC control module faulty.
Evaporator temperature sensor check 
  1. Check evaporator temperature sensor referring to A/C EVAPORATOR TEMPERATURE SENSOR INSPECTION .

Is it in good condition? 
HVAC control module faulty. Evaporator temperature sensor faulty.