Symptom Troubleshooting

WARNING: This page is about a different car, the 2013 Acura MDX, 2012 Acura MDX, 2011 Acura MDX, and 2010 Acura MDX. However, it is still accessible from the selected car via links, so may be relevant.

Troubleshoot the seat ventilation system in this order:

Order of priority	Symptom	Possible cause
1	Thermistor open	Measure the resistance between seat cushion heater 5P connector terminals No. 3 and No. 4. If the resistance value is at least 350 kΩ, the thermistor is faulty. Replace the seat cushion heater.
1	Thermistor open	Check for continuity between seat ventilation control unit 37P connector terminals No. 9 [No. 36] and No. 21 [No. 20] and seat cushion heater 5P connector terminals No. 4 and No. 3 respectively. If there is no continuity, repair an open in the wire.
2	Thermistor short	Measure the resistance between seat cushion heater 5P connector terminals No. 3 and No. 4. If the resistance value is 600 Ω or less, the thermistor is faulty. Replace the seat cushion heater.
2	Thermistor short	Disconnect the seat ventilation control unit 37P connector, and check for continuity between body ground and seat cushion heater 5P connector terminals No. 3 and No. 4 individually. If there is continuity, repair a short to ground in the wire.
3	Abnormal heater current	Go to the ventilated seat system input test, and do all power and ground input tests (see CONTROL UNIT INPUT TEST/REPLACEMENT ). If the tests prove OK, measure the resistance between seat cushion heater 5P connector terminals No. 2 and No. 5, and seat-back heater 2P connector terminals No. 1 and No. 2: If the resistance value of the seat cushion heater is out of the range between 4.3 and 5.2 Ω, the seat cushion heater is faulty. Replace the seat cushion heater. If the resistance value of the seat-back heater is out of the range between 4.6 and 5.6 Ω, the seat-back heater is faulty. Replace the seat-back heater.
3	Abnormal heater voltage	Go to the ventilated seat system input test, and do all power and ground input tests (see CONTROL UNIT INPUT TEST/REPLACEMENT ).
4	Seat ventilation switch failure	Go to the ventilated seat system input test, and do all power and ground input tests (see CONTROL UNIT INPUT TEST/REPLACEMENT ). If the tests prove OK, measure the resistance between seat cushion heater 5P connector terminals No. 2 and No. 5, and seat-back heater 2P connector terminals No. 1 and No. 2: If the resistance value of the seat cushion heater is out of the range between 4.3 and 5.2 Ω, the seat cushion heater is faulty. Replace the seat cushion heater. If the resistance value of the seat-back heater is out of the range between 4.6 and 5.6 Ω, the seat-back heater is faulty. Replace the seat-back heater. If the resistance value is within the specified value, replace the seat ventilation control unit.
5	Seat not heating
[]: Front passenger's seat