Piotrek6523888 Posted November 1, 2020 Share Posted November 1, 2020 Hi. I have ford focus mk3 and I'm trying to figure out if I need new battery or I have parasitic draw. I'm getting 0.38 draw after switching everything off. To my surprise I have pulled all the fuses one by one ( engine, passenger side and luggage compartment ) and the figure didn't change. Picture attached. Many thanks. Quote Link to comment Share on other sites More sharing options...
JW1982 Posted November 2, 2020 Share Posted November 2, 2020 What was the CANbus status when this value was measured? This is very important to determine whether this value is normal or not. If the CANbus system is still active every single CANbus module will consume power. Approximately 20 to 30 minutes after the car has been locked the CANbus system will enter sleep mode. In sleep mode every single CANbus module will only consume a bare minimum of power. 0.38 Amps x 12,5 Volts = 4.75 Watts. This value is completely normal when the CANbus system is still active. When the CANbus has entered sleep mode the consumed power should be about 0.025 to 0.04 Amps. 2 1 Quote Link to comment Share on other sites More sharing options...
Piotrek6523888 Posted November 2, 2020 Author Share Posted November 2, 2020 7 hours ago, JW1982 said: What was the CANbus status when this value was measured? This is very important to determine whether this value is normal or not. If the CANbus system is still active every single CANbus module will consume power. Approximately 20 to 30 minutes after the car has been locked the CANbus system will enter sleep mode. In sleep mode every single CANbus module will only consume a bare minimum of power. 0.38 Amps x 12,5 Volts = 4.75 Watts. This value is completely normal when the CANbus system is still active. When the CANbus has entered sleep mode the consumed power should be about 0.025 to 0.04 Amps. thank you sir for your reply. I shall re check it and see the value after 30 minutes. Quote Link to comment Share on other sites More sharing options...
st line x 140 driver Posted November 2, 2020 Share Posted November 2, 2020 Remember car has motion sensors constantly on incase of brake in. Probably monitored on the CANbus system. Quote Link to comment Share on other sites More sharing options...
Freeze Posted November 3, 2020 Share Posted November 3, 2020 I suggest locking the car and leaving the hood open, then wait 30 minutes. If you even unlock the doors (or jerk the car as mentioned), the CANbus is active again. Quote Link to comment Share on other sites More sharing options...
Ronderay Posted November 10, 2020 Share Posted November 10, 2020 Did you find the answer, new battery or parasitic draw. I’ve put a new £140 battery on my 2012 and it’s gone flat in 2 days. I’ve checked current draw and my meter reads 1.47 when I connect it. If I open a door it goes up to 6.89. When I lock it it drops down to 3.58. After a few minutes it drops back to 1.47. I have removed all the fuses and relays 1by1 with no drop from 1.47. I’ve also disconnected alternator lead and checked the diode circuit and that is as it should be. Anyone got any ideas Quote Link to comment Share on other sites More sharing options...
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