{"id":8654,"date":"2022-03-10T20:30:40","date_gmt":"2022-03-10T20:30:40","guid":{"rendered":"https:\/\/www.hexorcism.com\/19BP\/sm2334125\/"},"modified":"2022-03-10T20:30:40","modified_gmt":"2022-03-10T20:30:40","slug":"sm2334125","status":"publish","type":"page","link":"https:\/\/www.hexorcism.com\/19BP\/sm2334125\/","title":{"rendered":"ELECTRIC POWER STEERING (EPS) CONTROL MODULE [(US)]"},"content":{"rendered":"
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ELECTRIC POWER STEERING (EPS) CONTROL MODULE [(US)]<\/h3>\n<\/div>\n

SM2334125<\/p>\n

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id0613002455x1<\/p>\n



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Purpose\/ Function<\/p>\n

\u2022 The EPS CM calculates optimum assist force based on the steering torque signal from the torque sensor,the vehicle speed signal from the DSC HU\/CM, engine speed signal from the PCM, and EPS motor position information from the EPS motor, and outputs electric current to drive the EPS motor.<\/div>\n
\u2022 The following steering angle signals are output via CAN communication.<\/div>\n
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\u2015 Steering angle (relative angle) signal<\/div>\n
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\u2022 Set the steering position to when the ignition is switched ON (engine off or on) to output the steering angle when steering from that position.<\/div>\n<\/dd>\n<\/dl>\n
\u2015 Steering angle (estimated absolute angle) signal<\/div>\n
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\u2022 The EPS CM outputs the calculated steering angle value to the CAN as a steering angle (estimated absolute angle) signal for other systems requiring steering angle information.<\/div>\n<\/dd>\n<\/dl>\n<\/dd>\n<\/dl>\n
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Note<\/div>\n<\/dd>\n
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\u2022 The steering angle sensor signal is not used for the steering angle (estimated absolute angle) signal calculation.<\/div>\n
\u2022 After the steering angle neutral position auto learning is completed, the EPS CM outputs an EPS status signal, which is calculated by EPS CM itself, through the CAN communication.<\/div>\n<\/div>\n<\/dd>\n<\/dl>\n
\u2022 The EPS CM controls the following functions:<\/div>\n

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Function Table<\/p>\n\n\n\n\n\n\n\n\n\n
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Control item<\/p>\n<\/th>\n

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Function<\/p>\n<\/th>\n<\/tr>\n<\/thead>\n

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EPS motor current control<\/div>\n<\/td>\n
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\u2022 Normal control<\/div>\n
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\u2015 Calculates the proper assist current based on the steering torque, and the vehicle and engine speeds, and outputs a target current to the EPS motor.<\/div>\n<\/dd>\n<\/dl>\n
\u2022 System overheating protection control<\/div>\n
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\u2015 Monitors the temperature of the motherboard in the EPS CM and controls the motor current gradually to prevent overheating of the system.<\/div>\n<\/dd>\n<\/dl>\n
\u2022 EPS motor backup control<\/div>\n
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\u2015 Even if a phase 1 open circuit malfunction in the EPS motor occurs, output current to the EPS motor is controlled so that steering assist is maintained.<\/div>\n<\/dd>\n<\/dl>\n
\u2022 Torque sensor backup control<\/div>\n
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\u2015 Even if an error occurs in the torque sensor signal, the torque sensor backup control performs control to maintain steering assist to the extent possible.<\/div>\n<\/dd>\n<\/dl>\n
\u2022 Resolver sensor backup control<\/div>\n
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\u2015 Even if an open circuit malfunction occurs in the resolver sensor, the resolver sensor backup control performs control to maintain steering assist to the extent possible.<\/div>\n<\/dd>\n<\/dl>\n
\u2022 Current sensor backup control<\/div>\n
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\u2015 Even if a current sensor malfunction occurs, output current to the EPS motor is controlled so that steering assist is maintained.<\/div>\n<\/dd>\n<\/dl>\n
\u2022 IG backup control<\/div>\n
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\u2015 Even if an IG signal error occurs, output current to the EPS motor is controlled so that steering assist is maintained. However, the assist while the vehicle is stopped is ended.<\/div>\n<\/dd>\n<\/dl>\n<\/td>\n<\/tr>\n
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On-board diagnostic function<\/div>\n<\/td>\n
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\u2022 The main part of the system control includes the self-diagnosis function. In case a malfunction occurs, the power steering malfunction indication\/master warning light illuminates to alert the driver, and a DTC is stored in the EPS CM at the same time.<\/div>\n
\u2022 As a result of the on-board diagnosis, when a malfunction is determined, system control is suspended or limited to assure safety while driving.<\/div>\n<\/td>\n<\/tr>\n
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CAN communication function<\/div>\n<\/td>\n
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\u2022 Outputs the EPS status signal and the power steering malfunction indication illuminates on request via CAN lines.<\/div>\n
\u2022 Outputs the steering angle (absolute angle) signal, steering angle (relative angle) signal and steering angle (estimated absolute angle) signal.<\/div>\n<\/td>\n<\/tr>\n
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Automatic configuration function<\/div>\n<\/td>\n
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\u2022 When the ignition is switched to ON or the engine is started after the EPS CM have been replaced, the EPS CM reads data from the instrument cluster via CAN communication to perform automatic configuration.<\/div>\n<\/td>\n<\/tr>\n
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Steering wheel angle neutral position automatic learning function<\/div>\n<\/td>\n
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\u2022 When the ignition is switched from OFF to ON (engine on) and the vehicle is driven normally, the steering wheel angle neutral position is learned automatically based on the wheel speed signal, lateral-G signal, and yaw rate signal.<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n



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Construction<\/p>\n

\u2022 The EPS CM is installed to the steering column and integrated with the EPS motor.<\/div>\n
\u2022 For vehicles equipped with a system requiring steering angle information directly after the vehicle starts to be driven, a steering angle sensor is equipped.<\/div>\n


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Block Diagram<\/p>\n\n\n\n
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<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
am3zzn00007971<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n



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Operation<\/p>\n

\u2022 The EPS CM calculates the required assist torque based on the steering torque signal from the torque sensor. When the vehicle starts to be driven, the required assist torque is calculated based on the vehicle speed signal sent from the DSC HU\/CM via CAN in addition to the steering torque signal.<\/div>\n
\u2022 The EPS system control uses the steering angle (estimated absolute angle) signal.<\/div>\n
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Ignition is switched ON (engine off or on)<\/div>\n<\/dd>\n
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\u2015 The EPS CM regards the steering position when the ignition is switched ON (engine off or on) as , and outputs the steering angle value steered from that position as a steering angle (relative angle) signal.<\/div>\n<\/dd>\n<\/dl>\n
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Vehicle driving<\/div>\n<\/dd>\n
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\u2015 When the vehicle starts to be driven, the EPS CM performs steering wheel angle neutral position determination based on the following signals:<\/div>\n
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\u2022 Wheel speed signal: Determines straight-driving if there is no rotation speed difference between the left\/right wheels.<\/div>\n
\u2022 Lateral-G signal: Determines straight-driving if lateral-G is not produced.<\/div>\n
\u2022 Yaw rate signal: Determines straight-driving if yaw momentum is not produced.<\/div>\n<\/dd>\n<\/dl>\n
\u2015 If the EPS CM completes steering wheel angle neutral position determination, the steering angle neutral position is set. The EPS CM regards the steering wheel angle neutral position as , calculates the estimated absolute steering angle, and outputs the steering angle (estimated absolute angle) signal to CAN.<\/div>\n<\/dd>\n<\/dl>\n
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Ignition is switched off<\/div>\n<\/dd>\n
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\u2015 The steering wheel angle neutral position is cleared when 1 min or more<\/span> has elapsed after the ignition is switched off.<\/div>\n<\/dd>\n<\/dl>\n
\u2022 When the following controls are performed, the EPS CM stores a DTC and turns on the electric power steering warning light\/electric power steering warning indication.<\/div>\n
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\u2015 EPS motor backup control<\/div>\n
\u2015 Resolver sensor backup control<\/div>\n
\u2015 IG backup control<\/div>\n
\u2015 Current sensor backup control<\/div>\n
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\u2022 For details on the DTCs with which the electric power steering warning light\/electric power steering warning indication turns on, refer to the workshop manual.<\/div>\n
\u2022 For details on the electric power steering warning light\/electric power steering warning indication, refer to the POWER STEERING MALFUNCTION INDICATOR LIGHT\/POWER STEERING MALFUNCTION INDICATION.(See POWER STEERING MALFUNCTION INDICATOR LIGHT\/POWER STEERING MALFUNCTION INDICATION<\/a>.)<\/div>\n<\/dd>\n<\/dl>\n<\/dd>\n<\/dl>\n


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EPS Motor Current Control<\/p>\n

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Normal control<\/div>\n<\/dd>\n<\/dl>\n
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\u2022 The optimum assist current is calculated based on the steering force signal from the torque sensor and the vehicle speed signal from the DSC HU\/CM, and then the control current is output to the EPS motor.<\/div>\n<\/dd>\n<\/dl>\n
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System overheating protection control<\/div>\n<\/dd>\n<\/dl>\n
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\u2022 The system overheating protection control lowers the current output to the EPS motor if the steering mechanism is turned from lock to lock continuously or the steering rack turning limit is reached repeatedly.<\/p>\n
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Note<\/div>\n<\/dd>\n
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\u2022 During system overheating protection control, the assist force will feel weaker due to a decrease in the control current. This is normal for the EPS CM to prevent the EPS motor from burning or seizure, and it does not indicate a malfunction.<\/div>\n
\u2022 While the assist force weakens during this period of time, steering operation can be performed.<\/div>\n<\/div>\n<\/dd>\n<\/dl>\n<\/div>\n
\u2022 The system overheating protection control has high and low steps, and it can verify current conditions and the history using the PID\/data monitor function and snap shot data.<\/div>\n
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\u2015 System overheating protection control (high): Motor output is 80 % or less<\/span> (reference)<\/div>\n
\u2015 System overheating protection control (low): Motor output is 50 % or less<\/span> (reference)<\/div>\n<\/dd>\n<\/dl>\n
\u2022 The current output returns to normal if the temperature in the system decreases to the normal operation temperature.<\/p>\n\n\n\n
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<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
am3zzn00007972<\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/dd>\n<\/dl>\n
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EPS motor backup control<\/div>\n<\/dd>\n<\/dl>\n
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\u2022 Even if an open circuit malfunction occurs in 1 out of the 3 phases in the EPS motor line, the EPS motor backup control performs control to maintain steering assist.<\/div>\n
\u2022 If the EPS CM detects a phase 1 open circuit malfunction in the EPS motor, the EPS CM controls output current to the EPS motor using a calculation method different than during normal EPS CM control. As a result, even with a phase 1 open circuit malfunction, the steering assist can be maintained.<\/p>\n
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Note<\/div>\n<\/dd>\n
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\u2022 If the steering wheel is operated during EPS motor backup control, the steering wheel operation may feel heavier (resistance).<\/div>\n<\/dd>\n<\/dl>\n<\/div>\n<\/dd>\n<\/dl>\n
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Torque sensor backup control<\/div>\n<\/dd>\n<\/dl>\n
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\u2022 Even if an error is detected in the torque sensor signal, the torque sensor backup control performs control to maintain steering assist.<\/div>\n
\u2022 If the EPS CM detects a torque sensor signal error, the EPS CM controls output current to the EPS motor using a calculation method different from that during normal EPS CM control, and maintains steering assist.<\/p>\n
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Note<\/div>\n<\/dd>\n
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\u2022 If the steering wheel is operated during torque sensor backup control, normal assist force may not be generated.<\/div>\n<\/dd>\n<\/dl>\n<\/div>\n<\/dd>\n<\/dl>\n
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Resolver sensor backup control<\/div>\n<\/dd>\n<\/dl>\n
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\u2022 Even if an open circuit malfunction occurs in the resolver sensor, the resolver sensor backup control performs control to maintain steering assist.<\/div>\n
\u2022 If the EPS CM detects an open circuit malfunction in the resolver sensor, the EPS CM controls output current to the EPS motor using a calculation method different from that during normal EPS CM control. As a result, even with an open circuit in the resolver sensor, the steering assist can be maintained.<\/div>\n<\/dd>\n<\/dl>\n
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IG backup control<\/div>\n<\/dd>\n<\/dl>\n
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\u2022 Even if an error is detected in the IG signal, the IG backup control performs control to maintain steering assist.<\/div>\n
\u2022 If the EPS CM detects an IG signal error, the EPS CM controls output current to the EPS motor using a calculation method different from that during normal EPS CM control.As a result, even if an error occurs with the IG signal, the steering assist can be maintained. When the vehicle speed is 0 km\/h, assistance is stopped.<\/div>\n<\/dd>\n<\/dl>\n
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Current sensor backup control<\/div>\n<\/dd>\n<\/dl>\n
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\u2022 Even if an open circuit malfunction occurs in the current sensor, the current sensor backup control performs control to maintain steering assist.<\/div>\n
\u2022 If the EPS CM detects an open circuit malfunction in the current sensor, the EPS CM controls output current to the EPS motor using a calculation method different from? that during normal EPS CM control.As a result, even with an open circuit malfunction in the current sensor, the steering assist can be maintained.<\/div>\n<\/dd>\n<\/dl>\n<\/div>\n
<\/div>\n
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<\/div>\n

<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

ELECTRIC POWER STEERING (EPS) CONTROL MODULE [(US)] SM2334125 id0613002455x1 Purpose\/ Function \u2022 The EPS CM calculates optimum assist force based on the steering torque signal from the torque sensor,the vehicle speed signal from the DSC HU\/CM, engine speed signal from the PCM, and EPS motor position information from the EPS motor, and outputs electric current to drive the EPS motor. \u2022 The following steering angle signals are output via CAN communication. \u2015 Steering angle (relative […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-8654","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.hexorcism.com\/19BP\/wp-json\/wp\/v2\/pages\/8654","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hexorcism.com\/19BP\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.hexorcism.com\/19BP\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.hexorcism.com\/19BP\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.hexorcism.com\/19BP\/wp-json\/wp\/v2\/comments?post=8654"}],"version-history":[{"count":0,"href":"https:\/\/www.hexorcism.com\/19BP\/wp-json\/wp\/v2\/pages\/8654\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.hexorcism.com\/19BP\/wp-json\/wp\/v2\/media?parent=8654"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}