The purpose of this test is to evaluate the level of parasitic current draw from the battery during a vehicle's shutdown phase and sleep periods.
Connection for diagnostic work will vary dependent on application.
Technicians should whenever possible gain access to the test circuit without damage to seals and insulation. If this is not possible then make sure appropriate repairs are completed.
Parasitic drain test pre-requisites;
Vehicle must achieve full electrical shut down;
Ensure the test equipment is able to function for an extended time period e.g. current clamp battery condition, scope and pc power supply.
All values included in the example waveforms are typical and not specific to all vehicle types.
Refer to vehicle technical data for specific test conditions and results.
The battery voltage should remain stable and between 12.4 V and 12.8 V throughout the test. The current draw from the battery during the shutdown period of the vehicle networks and accessories is 228 mA for over 6 minutes. The shutdown periods can range from 30 minutes to 2 hours (depending on manufacturer). The current draw will also vary depending on network and system activity. You can clearly see a reduction in current draw from the battery as the networks begin to sleep and the parasitic current draw from the battery as it settles at 40 mA for over 21 minutes (sleep mode). The target parasitic drain is < 80 mA and stable throughout. It is clear on the waveform when the networks wake up, responding to the activation of the key fob/set. The vehicle is now unlocked and the networks are awake.
You can read more about Parasitic drain testing in the online training section on our website.
This help topic is subject to changes without notification. The information within is carefully checked and considered to be correct. This information is an example of our investigations and findings and is not a definitive procedure. Pico Technology accepts no responsibility for inaccuracies. Each vehicle may be different and require unique test settings.
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