To cool the engine and A/C compressor there are a two fans included. They are actuated according to a vehicle speed and water temperature dependent control logic. According to the electrical wiring there are two operation modes - low speed and high speed for the fans. The voltage after the A/C condensor fan relay is used to supply power to the A/C condensor fan. ECM determins the cooling fan speed by the water temperature sensor, vehicle speed sensor, A/C low & high pressure switch and A/C middle switch. If the pressure in the A/C circuit is high, A/C middle switch and A/C compressor is ON, then the radiator cooling fan and the condensor fan speed is set to high in order to fastly decrease the refrigerant pressure.
If the A/C condensor fan relay circuit is short to battery line or open during two driving cycles, this code will be set.
DTC NO.
Detecting Condition
Possible Cause
P 1628
P 1629
? P 1628
Short circuit to battery line
? P 1629
Open circuit :
? Short circuit to ground
? Wire broken
? Too high temperature in power stage
? Engine Condition : IG ON
? Fuel Limit : NO
? Fuel Cut : NO
? EGR OFF : NO
? MIL : NO
? Open or short in circuit
? Relay
? ECM