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DTC Troubleshooting

WARNING: This page is about a different car, the 2011 Suzuki SX4. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

When DTC B1502, B1503, B1504 and B1511 are indicated together, it is possible that sensor ground circuit is open.
When DTC B1511 is indicated together, it is possible that position sensor power supply circuit is open.

B1512: SYMPTOM TROUBLESHOOTING REFERENCE CHART

Step	Action	YES	NO
1	Was "Air Conditioning System Check" performed?	Go to Step 2.	Go to AIR CONDITIONING SYSTEM CHECK: AUTO A/C .
2	Wire harness check Turn ignition switch to OFF position. Disconnect connectors from air flow control actuator and HVAC control module. Check for proper connection to position sensor power supply, signal and ground circuit terminals of air flow control actuator and HVAC control module connectors. If OK, check that position sensor of air flow control actuator circuit is as follows. Wiring harness resistance of each position sensor power supply, signal and ground circuit is less than 3 Ω Insulation resistance of each position sensor power supply, signal and ground circuit is infinity between air flow control actuator connector and vehicle body ground Circuit voltage of each position sensor power supply, signal and ground circuit is 0 - 1 V with ignition switch turned ON Are they in good condition?	Go to Step 3.	Position sensor power supply, signal circuit and/or ground circuit are open, short or high resistance.
3	Position sensor of air flow control actuator power supply voltage check Connect connector to HVAC control module with ignition switch turned OFF. Turn ignition switch to ON position. Measure voltage between. Position sensor power supply terminal and position sensor ground terminal of air flow control actuator connector Position sensor signal terminal and position sensor ground terminal of air flow control actuator connector Is voltage 4.5 - 5.5 V?	Go to Step 4.	Go to Step 5.
4	Air flow control actuator check Check position sensor of air flow control actuator for performance referring to AIR FLOW CONTROL ACTUATOR AND ITS CIRCUIT INSPECTION: AUTO A/C . Is it in good condition?	Substitute a known-good HVAC control module and recheck.	Replace air flow control actuator.
5	Position sensor of air flow control actuator power supply voltage check Turn ignition switch to OFF position. Disconnect connector from temperature control actuator. Turn ignition switch to ON position. Measure voltage between. Position sensor power supply terminal and position sensor ground terminal of air flow control actuator connector Position sensor signal terminal and position sensor ground terminal of air flow control actuator connector Is voltage 4.5 - 5.5 V?	Check temperature control actuator and its circuit.	Substitute a known-good HVAC control module and recheck.