Test Methods
For the check of EPS system,use the decoder to get the malfunction code when the malfunction indicator lamp is on,and operate according to the instructions of the malfunction code.
(1)When checking the power circuit,keep the voltage of the battery above 12 V,and then check the two power lines(as shown in Fig.5.4),and the stitching A should be the voltage of the storage battery.But when the ignition switch is on,the stitching 1 should be the voltage of the battery,if not,check whether the power line is cut off and the fuse is burnt or not.
Fig.5.4 Power lines
(2)For the grounding,check the resistance between the stitching B(as shown in Fig.5.5)and grounding under the condition that power is off and see whether the value is below 5 Ωor not.Otherwise,check whether the grounding line is cut off or not.
Fig.5.5 Grounding Line(https://www.daowen.com)
(3)Refer to the Chapter 2 CAN-BUS system for the check of CAN line
Note:
The device with high voltage or large current may induce the circuit so as to disturb the normal work of circuit.
EPS components are sensitive to the EMI.If you doubt there is intermittent failure,check whether the anti-theft device,lamps or MP installed after sale are properly installed or not.
Check if the standard pieces are damaged or modified.
Steering column assembly must be replaced entirely,and no dssmantling is permitted.