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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 B1512 are indicated together, it is possible that sensor ground circuit is open.
When DTC B1512 is indicated together, it is possible that position sensor power supply circuit is open.

B1511: 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 temperature control actuator and HVAC control module. Check for proper connection to position sensor power supply, signal and ground circuit terminals of temperature control actuator and HVAC control module connectors. If OK, check that position sensor of temperature 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 temperature 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 temperature control actuator power supply voltage check Connect connector to HVAC control module. Turn ignition switch to ON position. Measure voltage between. Position sensor power supply terminal and position sensor ground terminal of temperature control actuator connector Position sensor signal terminal and position sensor ground terminal of temperature control actuator connector Is voltage 4.5 - 5.5 V?	Go to Step 4.	Go to Step 5.
4	Temperature control actuator check Check position sensor of temperature control actuator for performance referring to TEMPERATURE CONTROL ACTUATOR AND ITS CIRCUIT INSPECTION: AUTO A/C . Is it in good condition?	Substitute a known-good HVAC control module and recheck.	Replace temperature control actuator.
5	Position sensor of temperature control actuator power supply voltage check Turn ignition switch to OFF position. Disconnect connector from air flow control actuator. Turn ignition switch to ON position. Measure voltage between. Position sensor power supply terminal and position sensor ground terminal of temperature control actuator connector Position sensor signal terminal and position sensor ground terminal of temperature control actuator connector Is voltage 4.5 - 5.5 V?	Check air flow control actuator and its circuit.	Substitute a known-good HVAC control module and recheck.