Electronic Power Assist Steering: Overview — Ford Explorer V (2010-2015)

Overview

The EPAS system provides steering assist to the driver by replacing the conventional, hydraulic valve system with a steering gear equipped with an integrated electrical motor and PSCM . The motor operation and level of steering assist provided is controlled by the PSCM .

Scheme 1

Scheme 1: System Diagram

Principles of Operation

SPECIAL TOOLS DESCRIPTION CHART Flex Probe Kit 105-R025D or equivalent Fluke 77-IV Digital Multimeter FLU77-4 or equivalent Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool

Scheme 2

Scheme 2: Principles of Operation

Scheme 3

The Electronic Power Assist Steering (EPAS) system provides power steering assist to the driver by replacing the conventional hydraulic valve system with an electric motor coupled to the steering rack by a toothed belt. The motor is controlled by the Power Steering Control Module (PSCM) that senses steering effort/use through the use of a torque sensor which is mounted near the input shaft of the steering gear. Steering assist is provided in proportion to the steering input effort and vehicle speed.

The EPAS system requires a 12-volt, hot at all times feed for system operation. The PSCM is activated when power is applied to the hard-wired ignition/run input. After activation, the PSCM monitors the High Speed Controller Area Network (HS-CAN) bus to determine if the vehicle is operating in a manner capable of supporting the EPAS system.

Once this is determined, vehicle speed sent by the PCM over the HS-CAN bus, steering shaft speed and direction sent by the torque sensor and steering wheel angle/position determined by the motor position all provide the necessary information for the PSCM to determine the amount or level of assist provided by the EPAS system.

Assist is primarily based off of vehicle speed. As vehicle speed increases, the amount of assist provided by the system is decreased to improve and enhance road feel at the steering wheel. As vehicle speed decreases, the amount of assist provided by the system is increased to ease vehicle maneuvering. If the vehicle speed is missing or out of range, the PSCM defaults to a safe level of assist for all driving conditions. If the vehicle speed returns to the correct in-range values, the PSCM will adjust the level of assist accordingly. Steering wheel/shaft speed, torque and direction information will allow the PSCM to determine how much assist is needed to turn the wheels right and left.

The PSCM is self-monitoring and has the capability of setting and storing DTCs. Depending on the DTC set, the control module will enter into a "safe mode" of manual steering. In addition, the PSCM may send a request to the Instrument Panel Cluster (IPC) module over the HS-CAN bus to display a message in the message center to alert the driver of a potential EPAS concern.

Description

RETRIEVE and FOLLOW all PSCM DTC Index - Power Steering Control Module (PSCM) .

The power steering control module (PSCM) uses a thermistor to monitor the internal temperature of the electronic power assist steering (EPAS) gear. This DTC appearing by itself does not indicate a fault condition in the steering system. Diagnose all other EPAS DTCs before diagnosing B1D23:68.

DTC B1D23:68 (Overheat Sensor: Event Information) - This DTC sets if the internal temperature of the EPAS gear exceeds a predetermined threshold. When this DTC is set steering assist will be reduced, but not removed. If equipped with active park assist, park assist is removed when this DTC is set.

While the ignition is ON and the voltage supply to the PSCM is above 6 volts, the module will monitor the motor inside the EPAS gear to calculate the relative and actual steering wheel angle. This value is then transmitted to other modules over the high-speed controller area network (HS-CAN) bus.

DTC C1B00:2F (Steering Angle Sensor: Signal Erratic) - This DTC sets if the steering angle sensor signal is calculated to be outside the expected range. This DTC is set if the PSCM determines that the steering angle reached has exceeded the available rack length.
DTC C1B00:62 (Steering Angle Sensor: Signal Compare Failure) - This DTC sets if the calculated signal does not match other sensor inputs.

The PSCM continually monitors the steering shaft torque sensor when the ignition is ON and the voltage supply to the PSCM is above 6 volts.

DTC C200B:2F (Steering Shaft Torque Sensor 1: Signal Erratic) - If the steering shaft torque sensor signal is outside the expected range, then DTC C200B:2F will be set.
DTC C200B:61 (Steering Shaft Torque Sensor 1: Signal Calculation Failure) - If the steering shaft torque sensor signal is not within a certain threshold, then DTC C200B:61 will be set.
DTC C200B:62 (Steering Shaft Torque Sensor 1: Signal Compare Failure) - If the steering shaft torque sensor signal does not match other sensor input, then DTC C200B:62 will be set.

The PSCM continually monitors the steering shaft torque sensor when the ignition is ON and the voltage supply to the PSCM is above 6 volts.

DTC C200C:2F (Steering Shaft Torque Sensor 2: Signal Erratic) - If the steering shaft torque sensor signal is outside the expected range, then DTC C200C:2F will be set.

The PSCM continually monitors the motor position angle sensor when the ignition is ON and the voltage supply to the PSCM is above 6 volts.

DTC C200D:49 (Motor Rotation Angle Sensor: Internal Electronic Failure) - If the signal from the sensor is missing or does not match other sensor input, then DTC C200D:49 will be set.

The PSCM will monitor the amount of force needed to assist with vehicle steering when the ignition is ON and the voltage supply to the PSCM is above 6 volts, all other EPAS sensors are functioning correctly and the EPAS gear is providing assist.

DTC P07AE:09 (Transmission Friction Element G Performance/Stuck Off: Component Failure) - If the amount of friction in the steering system exceeds the allowable threshold, DTC P07AE:09 will be set. Low air pressure in the tires could cause DTC P07AE:09 to set.

The PSCM will monitor the HS-CAN bus when the ignition has been on for more than 5 seconds, when the voltage to the PSCM is greater than 9 volts and when there are no DTCs present that are inhibiting PSCM operation.

DTC U0001:88 (High Speed CAN Communication Bus: Bus Off) - This DTC will set if the PSCM detects that transmission of HS-CAN bus messages is not acknowledged by other modules for 400 milliseconds or if the HS-CAN bus is deemed to have a communication error for greater than 5 seconds.

DTC U0100:00 (Lost Communication with ECM/PCM A: No Sub Type Information) - This DTC sets if communications between the PSCM and the PCM fail. If the engine speed/vehicle speed message is missing for more that 40 ms or the battery management message is missing for more than 200 ms, this DTC sets.

DTC U0121:00 (Lost Communication with the Anti-lock Brake System (ABS) Control Module: No Sub Type Information) - This DTC sets when communication between the PSCM and the ABS module fails. If the wheel speed message is missing for 1 second or the steering wheel component angle message is missing for 5 seconds, this DTC sets.

DTC U0126:00 (Lost Communication With the Steering Angle Sensor Module: No Sub Type Information) - This DTC sets if the communication between the PSCM and the SCCM fails. If the PSCM does not receive the steering angle message from the SCCM for more than 40 ms this DTC sets.

Refer to DIAGNOSTIC ROUTINE D .

DTC U0151:00 (Lost Communication with Restraints Control Module: No Sub Type Information) - This DTC sets when communication between the PSCM and the RCM fails. The PSCM has not received the acceleration data message from the RCM for 5 seconds.

Refer to DIAGNOSTIC ROUTINE M .

Note. The parking assist control module is integral to the parking aid module.

DTC U0159:00 (Lost Communication With Parking Assist Control Module A: No Sub Type Information) - This DTC sets if communication between the PSCM and the Parking Aid Module (PAM) module fails. If the steering angle request message from the PAM is missing for 40 ms this DTC sets.

DTC U0300:00 (Internal Control Module Software Incompatibility: No Sub Type Information) - This DTC is set if the PSCM detects a configuration data failure or a mismatch between the stored and retrieved data during self-test. This DTC is usually set if the PSCM has recently been flashed and the flash was done incorrectly or was interrupted.

DTC U0401:00 (Invalid Data Received from ECM/PCM A: No Sub Type Information) - This DTC sets if the PSCM receives invalid or unknown messages from the PCM for 10 ms instead of the valid engine speed, engine state and vehicle speed data messages.

DTC U0415:00 (Invalid Data Received From Anti-Lock Brake System [ABS] Control Module: No Sub Type Information) This DTC sets if the PSCM receives an invalid or unknown steering angle message or the wheel speed message indicates a fault for more than 1 second.
DTC U0415:22 (Invalid Data Received from Anti-Lock Brake System [ABS] Control Module: Signal Amplitude > Maximum) - This DTC sets if the PSCM detects an invalid or unknown message from the ABS module. This DTC sets if the steering angle message value received by the PSCM, exceeds the maximum steering gear travel.

This DTC sets when the PAM receives invalid network data from the BCM with a faulted signal data input. RETRIEVE and REPAIR all non-network DTCs in the other modules on the network.

This DTC sets when the PAM receives invalid network data from the IPC with a faulted signal data input. RETRIEVE and REPAIR all non-network DTCs in the other modules on the network.

DTC U0428:00 (Invalid Data Received from Steering Angle Sensor Module: No Sub Type Information) - This DTC sets if the PSCM receives an invalid or unknown message from the SCCM instead of the actual steering angle data.

DTC U0452:00 (Invalid Data Received From Restraints Control Module: No Sub Type Information) - This DTC sets if the PSCM receives an invalid or incorrect message from the RCM. This DTC sets If the lateral acceleration message data from the RCM is invalid or missing for more than 5 seconds.
DTC U0452:22 (Invalid Data Received from Restraints Control Module: Signal Amplitude Greater Than Maximum) - This DTC sets if the lateral acceleration message from the RCM indicates a vehicle lateral acceleration greater that the pre defined limit.

Note. The parking assist control module is integral to the parking aid module.

DTC U045A:00 (Invalid Data Received from Parking Assist Control Module A: No Sub Type Information) - This DTC sets if the PSCM detects an invalid steering angle request signal transmitted by the PAM.

The PSCM will carry out a self-test of the motor inside the EPAS gear during vehicle start up and monitor the motor during normal driving conditions with voltage at the PSCM between 10 and 17 volts.

DTC U2011:49 (Motor: Internal Electronic Failure) - If motor voltage output falls below or exceeds a predetermined threshold, DTC U2011:49 will be set.
DTC U2011:61 (Motor: Signal Calculation Failure) - If the integrity of the motor torque estimate or motor velocity signal exceeds or does not meet a calculated value, then DTC U2011:61 will be set.

When the EPAS gear is installed, the PSCM must be configured with the vehicle information. Configuration is checked during initial PSCM power up (ignition ON) with the voltage supply to the PSCM greater than 6 volts.

DTC U2100:00 (Initial Configuration Not Complete: No Sub Type Information) - This DTC sets if the initial PSCM configuration was not carried out or if the configuration fails. This DTC sets if PSCM detects the vehicle data configuration or the component base data configuration is missing or incomplete.

With Adaptive Cruise Control

This DTC sets when the C-CM detects the BCM is not transmitting the correct configuration information. The BCM needs to be configured.
CHECK the vehicle service history for recent service actions related to this module. This DTC sets due to incomplete or incorrect PMI procedures. If there have been recent service actions with this module, REPEAT the PMI procedure as directed by the scan tool (REFER to «PROGRAMMABLE MODULE INSTALLATION (PMI)»(ref-517596-S07367743742012121200000) . If there have been no recent service actions, INSTALL a new module to correct the failure to retain configuration data. REFER to «CRUISE CONTROL MODULE (C-CM)»(ref-517603-S02009440042012121200000) .

Without Adaptive Cruise Control

CHECK the service history for recent service actions related to the ABS. This DTC sets due to incomplete or improper PMI procedures.
If there have been recent service actions with this module, REPEAT the PMI using as-built data.
If there have been no recent service actions and the vehicle is not equipped with adaptive cruise control, INSTALL a new ABS module. REFER to «ANTI-LOCK BRAKE SYSTEM (ABS) MODULE»(ref-517557-S32788947712012121200000) .
If there have been no recent service actions and the vehicle is equipped with adaptive cruise control, INSTALL a new ABS module and HCU. REFER to «HYDRAULIC CONTROL UNIT (HCU)»(ref-517557-S31980121252012121200000)

The PSCM is self monitoring and will carry out self-tests at specific intervals (initial power up, power down, during normal operation, etc.). Each self-test requires the voltage supply to the PSCM to be at or above a specific level (above 6 volts, above 9 volts, between 11 and 16 volts, etc.) for the test to take place. If one or more of the self-tests fail, the module sets one or more DTCs.

DTC U3000:41 (Control Module: General Checksum Failure) - If at any time during normal operation the module detects an internal software error with more than 6 volts supplied to the PSCM, DTC U3000:41 sets.
DTC U3000:46 (Control Module: Calibration/Parameter Memory Failure) - If at any time during normal operation with more than 6 volts supplied to the PSCM the module determines that one or more calibration files are missing/corrupt or that the incorrect EPAS gear is installed to the vehicle, DTC U3000:46 sets.
DTC U3000:49 (Control Module: Internal Electronic Failure) - If at any time during normal operation with more than 6 volts supplied to the PSCM the module detects a software or internal hardware error, DTC U3000:49 is set.
DTC U3000:61 (Control Module: Signal Calculation Failure) - If the PSCM detects that assist torque calculation is faulty due to a software failure in the module, then DTC U3000:61 sets.
DTC U3000:72 (Control Module Actuator Stuck Open) - During initial power up with voltage greater than 9 volts the PSCM checks the internal relay voltage. If voltage is not present the module makes several attempts to close the relay. If no voltage is detected during the test period, DTC U3000:72 sets.
DTC U3000:96 (Control Module: Component Internal Failure) - This DTC sets if there is an internal failure of the PSCM or if multiple failures have occurred over a short period of time.

Refer to DIAGNOSTIC ROUTINE L .

The PSCM will monitor the voltage supplied by the 12-volt battery and charging system and set the appropriate DTC when necessary.

DTC U3003:16 (Battery Voltage: Circuit Voltage Below Threshold) - If the voltage supply to the PSCM falls below 9 volts with the ignition ON and the engine speed above 500 rpm, DTC U3003:16 sets.
DTC U3003:17 (Battery Voltage: Circuit Voltage Above Threshold) - If the voltage supply to the PSCM exceeds 20 volts for 10 minutes with the ignition ON, then DTC U3003:17 will be set.
DTC U3003:68 (Battery Voltage: Event Information) - This DTC sets if one of the following conditions is present

The engine speed has been greater than 500 rpm for more than 5 seconds and the voltage supply is less than 10.8 volts with no alternator fault message present.

The engine speed has been greater than 500 rpm for more than 5 seconds and the voltage supply is less than 11.8 volts with an alternator fault message present.

The engine speed has been greater than 500 rpm for more than 5 seconds and the voltage supply is greater than 16 volts.

Normal Operation

The power steering control module (PSCM) is supplied voltage through one high current and one low current circuit. The low current circuit is dedicated for PSCM module power. This allows the PSCM to monitor and detect system power concerns on the high current circuit. The entire electric power assist steering (EPAS) system uses one ground. Although the ground circuit is not directly monitored, ground circuit concerns may be interpreted by the PSCM as voltage supply concerns. Specific circuit schematics are provided in POWER STEERING CONTROLS .

Concerns with the vehicle electrical system or with the circuits described above may result in reduced steering assist. If voltage levels reach specific fault trigger conditions a message will be displayed in the message center and the PSCM will store a U3003 DTC. The specific fault trigger conditions associated with the U3003 DTCs are listed in the DTC Index.

Note. Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

Scheme 4

Scheme 4: Normal Operation

Circuit	Pin
GND (Ground) - GD108	2(BLACK/VIOLET)
B+ (Battery Positive Voltage) - SBF05	1(GRAY/RED)

Harness Side

A1: CHECK PSCM DTCS Review the returned PSCM DTCs. NOTE: The PSCM reporting only EPAS Event Information DTCs (xxxxx:68) does not indicate a concern with the EPAS system. Are EPAS Event Information DTCs (xxxxx:68) the only DTCs present? Yes: No: Go to A2. Go to A3 .
A2: FAULT CONDITION CONFIRMATION If DTC U3003:68 is present and the steering assist is unaffected, the DTC may have been set due to the battery voltage dropping below the required parameters during engine cranking. Is the vehicle experiencing heavy steering or a lack of steering assist? Yes: No: REFER to «CHARGING SYSTEM»(ref-517537) to diagnose the battery and charging system. CLEAR the DTCs. REPEAT the self-test. This fault may have been caused by the battery voltage dropping below the required parameters during engine cranking.
A3: RETRIEVE ALL CMDTCS FROM ALL MODULES Ignition ON, engine running. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions. Is the PCM AND at least one other module in addition to the PSCM reporting charging system and/or battery voltage DTCs? Yes No REFER to «CHARGING SYSTEM»(ref-517537) to diagnose the battery and charging system. Go to A4.
A4: CHECK THE CONDITION OF THE BATTERY Ignition OFF. REFER to «BATTERY, BATTERY MOUNTING & BATTERY CABLES»(ref-517589) and implement Pinpoint Test A: Battery - Condition Test. Does the battery pass the condition test? Yes: No: Go to A5. INSTALL a new 12-volt battery. Refer to «BATTERY»(ref-517589-S36949793152012121200000) . Clear the PSCM DTCs. REPEAT the self-test.
A5: CHECK THE BATTERY STATE OF CHARGE Review the results from the battery condition test. Did the battery require a recharge? Yes: No: REFER to «CHARGING SYSTEM»(ref-517537) to diagnose the battery and charging system. Go to A6.
A6: CHECK CHARGING SYSTEM VOLTAGE Ignition ON, engine running. Turn off all accessories. Measure the voltage between: (+) 12 Volt Vehicle Battery (-) 12 Volt Vehicle Battery Positive terminal Negative terminal Turn the headlamps on and set the HVAC fan to high. Measure the voltage between: (+) 12 Volt Vehicle Battery (-) 12 Volt Vehicle Battery Positive terminal Negative terminal Are the voltages between 13 and 15.2 volts? Yes: No: Go to A7. REFER to «CHARGING SYSTEM»(ref-517537) to diagnose the battery and charging system.
A7: CHECK THE BATTERY VOLTAGE STATUS PID Turn the steering wheel from lock to lock with the vehicle running and note the PID reading while holding the wheel in a lock position. Access the PSCM and monitor the MOD_SUP_V (VOLT) PID. Does the PID match the loaded battery voltage +/- 1.5 volts? Yes: No: An intermittent fault may be present in the wiring harness. Visually check for chaffed wires or other physical damage to the harness. If no fault is found in the circuit, suspect the following component(s): PSCM_A Connector PSCM_B Connector Clear the PSCM DTCs. REPEAT the self-test. Go to A10 .
A8: CHECK THE BATTERY VOLTAGE STATUS PID Turn the steering wheel from lock to lock with the vehicle running and note the PID reading while holding the wheel in a lock position. Access the PSCM and monitor the MOD_SUP_V (VOLT) PID. Does the PID match the loaded battery voltage +/- 1.5 volts? Yes: No: An intermittent fault may be present in the wiring harness. Visually check for chaffed wires or other physical damage to the harness. If no fault is found in the circuit, suspect the following component(s): PSCM_A Connector PSCM_B Connector CLEAR the DTCs. REPEAT the self-test. Go to A10 .
A9: CHECK THE PSCM BATTERY VOLTAGE INPUT CIRCUIT FOR AN OPEN Ignition OFF. Battery Junction Box_F1 connector disconnected. Battery Junction Box_F2 connector disconnected. PSCM_A connector disconnected. (C1463A) Measure the resistance between: (+) Battery Junction Box_F1, Harness Side (-) PSCM_A (C1463A) Connector, Harness Side PSCM B+ B+ - SBF05 - Pin 1 Measure the resistance between: (+) Battery Junction Box_F2, Harness Side (-) PSCM_A (C1463A) Connector, Harness Side PSCM B+ B+ - SBF05 - Pin 1 Is the resistance less than 0.5 Ohm? Yes: No: Go to A12 . REPAIR the open circuit. INSPECT the PSCM connectors for corrosion, spread terminals and pushed-out terminals. REPAIR as necessary. If the connectors are okay, REPAIR the PSCM battery voltage input circuit. Clear the PSCM DTCs. REPEAT the self-test.
A10: CHECK THE PSCM BATTERY VOLTAGE INPUT CIRCUIT FOR AN OPEN Ignition OFF. Disconnect the positive battery cable, refer to the «BATTERY DISCONNECT»(ref-517589-S39248827582012121200000) . PSCM_A connector disconnected. (C1463A) Measure the resistance between: (+) Vehicle Battery (-) PSCM_A (C1463A) Connector, Harness Side Positive terminal B+ - SBF05 - Pin 1 Is the resistance less than 0.5 Ohm? Yes: No: Go to A12 . REPAIR the open circuit. INSPECT the PSCM connectors for corrosion, spread terminals and pushed-out terminals. REPAIR as necessary. If the connectors are okay, REPAIR the PSCM battery voltage input circuit. Clear the PSCM DTCs. REPEAT the self-test.
A11: CHECK THE PSCM BATTERY VOLTAGE INPUT CIRCUIT FOR AN OPEN Ignition OFF. High-current Battery Junction Box connector disconnected. PSCM_A connector disconnected. (C1463A) Measure the resistance between: (+) High-current Battery Junction Box Connector, Harness Side (-) PSCM_A (C1463A) Connector, Harness Side B+ B+ - SBF05 - Pin 1 Is the resistance less than 0.5 Ohm? Yes: No: Go to A12. REPAIR the open circuit. Clear the PSCM DTCs. REPEAT the self-test.
A12: CHECK THE PSCM GROUND Inspect ground G101 for looseness and corrosion. Are the ground bolt and eyelet tight and free from any corrosion? Yes: No: INSPECT the PSCM wiring harness and connectors for damage, corrosion, spread terminals or pushed out pins. If the connectors are okay, REPAIR the PSCM ground circuit. CLEAN and TIGHTEN ground connection. CLEAR the DTCs. REPEAT the self-test.

The power steering control module (PSCM) monitors various inputs and outputs of the electronic power assist steering (EPAS) system in order to keep the system operating at peak capacity. Information provided by sensors (steering torque, vehicle speed, vehicle travel distance, etc.) are all compared to programmed and learned information. Likewise, outputs like the motor and steering rack (travel) are tested against programmed and learned information.

Note. If a damaged bellows boot(s) was discovered during Inspection and Verification and this pinpoint test DOES NOT lead to the installation of a new EPAS gear or bellows boot(s), then go to PINPOINT TEST K to address the damaged boot(s) before returning the vehicle to the customer.

B1: CHECK FOR PREVIOUSLY SET DTCS Go to «KNOWN CONCERNS»(ref-517538-S14122661412013021300000) . Check for DTCs listed in the System Related CMDTCs cleared since initial read. Are any of the following DTCs present? PSCM DTCs C1B00:2F, C1B00:62, C200B:2F, C200B:61, C200B:62, U2011:61, U2200:54, U3000:41, U3000:46, U3000:49. Yes: No: Go to B2. Go to B2.
B2: INSPECT EPAS GEAR WIRING HARNESS With the vehicle in NEUTRAL, position it on a hoist. Refer to «JACKING & LIFTING»(ref-517532) . Ignition OFF. Thoroughly inspect the wire harness along the top of the EPAS gear for cuts, breaks and pinched wires. Disconnect all 3 EPAS gear electrical connectors and inspect them for corrosion, pushed-out pins, bent pins and spread terminals. Is the wire harness undamaged and are all 3 connectors in good condition? Yes: No: CONNECT all 3 EPAS gear electrical connectors. Go to B3. If the connector(s) are not okay, then REPAIR them. Otherwise, REPAIR the wire harness and whatever caused the damage to the wire harness. Go to B3.
B3: TEST DRIVE TO CHECK FOR RETURNING DTCS NOTE: Always drive the vehicle in a safe manner according to driving conditions and obey all traffic laws. Clear the PSCM DTCs. Cycle the ignition to OFF and then back to RUN. Test drive the vehicle in the following manner: With the engine running/ready, stop the vehicle on an unsealed concrete or asphalt surface (in order to provide adequate friction for a thorough test). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. The test drive is complete. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions.

C1: CHECK PSCM DTCS Review the returned PSCM DTCs. Is DTC U3000:96 present? Yes: No: INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . Go to C2.
C2: VERIFY PRESENCE OF EPAS GEAR HEAT SHIELD Make sure the EPAS gear heat shield is present and installed correctly. Refer to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . Is the heat shield present and is it installed correctly? Yes: No: Go to C3. REINSTALL the heat shield or INSTALL a new heat shield as necessary. Go to C3.
C3: TEST DRIVE TO CHECK FOR RETURNING DTCS Clear the PSCM DTCs. Cycle the ignition to OFF and then back to RUN. NOTE: Always drive the vehicle in a safe manner according to driving conditions and obey all traffic laws. Test drive the vehicle in the following manner: With the engine running/ready, stop the vehicle on an unsealed concrete or asphalt surface (in order to provide adequate friction for a thorough test). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. NOTE: The next portion of the test drive will require the vehicle to be driven at highway speeds. NOTE: The test period is a cumulative time of 10 minutes. Stopping, going slower than 72 km/h (45 mph) or faster that 96 km/h (60 mph) will not affect the test as long as a total time of 10 minutes is spent between 72-96 km/h (45-60 mph) with at least 4 lane changes during that time/speed window. Continue test driving the vehicle in the following manner: Bring the vehicle to a minimum speed of 72 km/h (45 mph), maximum of 96 km/h (60 mph). Maintain that speed for at least 10 minutes. During this 10-minute time period, make a minimum of 4 lane changes or turns that achieve a steering wheel angle of at least 20 degrees. The test drive is complete. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions. Is DTC U3000:61 and/or U3000:96 present? Yes No INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . The condition to set the DTC is not present at this time. RETURN the vehicle to the customer. For all other PSCM DTCs, REFER to the «DTC Index - Power Steering Control Module (PSCM)»(ref-517538-S38313120542013021300000) .

When the ignition is turned ON a relay inside the power steering control module (PSCM) is energized, which sends power to other portions of the module. The PSCM monitors this relay output and will set a DTC if output is not detected.

D1: CHECK FOR RETURNING DTCS Clear the PSCM DTCs. Cycle the ignition to OFF and then back to RUN. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions. Is DTC U3000:72 present? Yes No INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . The condition to set the DTC is not present at this time. In cold climates or climates where frost is possible, the relay contacts could develop a layer of frost which may prevent a clean connection between the relay contacts. It may be necessary to allow the vehicle to remain outside overnight in a cold climate to duplicate the DTC trigger conditions. If the DTC was set during cold or frosty conditions, attempt to recreate the fault by allowing the vehicle to remain overnight in a cold or frosty environment. Go to D2. If the DTC was not set during cold or frosty conditions, RETURN the vehicle to the customer. No fault found. The condition which caused the concern is not present at this time.
D2: ATTEMPT TO RECREATE THE FAULT CONDITIONS Park the vehicle in a cold or frosty environment and allow it to remain there overnight. NOTE: Do not allow the vehicle to warm up before carrying out the PSCM self-test. Ignition ON, engine OFF. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions. Is DTC U3000:72 present? Yes No INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . The condition to set the DTC is not present at this time. RETURN the vehicle to the customer.

The power steering control module (PSCM) will use the motor inside the electronic power assist steering (EPAS) gear to calculate the relative and actual steering wheel angle, and then transmit this information to other modules over the high-speed controller area network (HS-CAN) bus.

E1: TEST DRIVE TO CHECK FOR RETURNING DTCS NOTE: Always drive the vehicle in a safe manner according to driving conditions and obey all traffic laws. Clear the PSCM DTCs. Cycle the ignition to OFF and then back to RUN. Test drive the vehicle in the following manner: With the engine running/ready, stop the vehicle on an unsealed concrete or asphalt surface (in order to provide adequate friction for a thorough test). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. The test drive is complete. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions. Is DTC C1B00:2F present? Yes No Go to E2. The condition to set the DTC is not present at this time. DISCONNECT and INSPECT all 3 PSCM connectors for corrosion, bent terminals and/or pushed-out pins. REPAIR as necessary. If the connectors are okay, INSPECT the wire harness along the top of the EPAS gear for cuts, breaks and/or pinches. REPAIR as necessary. For all other PSCM DTCs, REFER to the «DTC Index - Power Steering Control Module (PSCM)»(ref-517538-S38313120542013021300000) .
E2: INSPECT THE INNER TIE RODS With the vehicle in NEUTRAL, position it on a hoist. Refer to «JACKING & LIFTING»(ref-517532) . NOTE: When installing new bellows boots and clamps apply new lubricant as instructed to prevent water contamination or damage may result to the electronic power assist steering (EPAS) gear. For complete information refer to the «Tie Rod - Inner»(ref-517538-S31843199942012121200000) . Inspect the inner tie rods for correct installation. Refer to «Tie Rod - Inner»(ref-517538-S31843199942012121200000) . Are the inner tie rods correctly installed? Yes: No: INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . INSTALL new inner tie rod(s), bellows boot(s) and clamps as necessary. REFER to «Tie Rod - Inner»(ref-517538-S31843199942012121200000) .

F1: CHECK AND RECORD THE LEFT FRONT AND RIGHT FRONT TIRE PRESSURES Check and record the left front and right front tire pressures. Compare the recorded tire pressure readings with the information on the vehicle certification (VC) label. Is the air pressure in the tires correct as indicated on the VC label? Yes: No: Go to F2. ADJUST the air pressure in the tires. Go to F2.
F2: CHECK FOR UNLOADED STEERING RACK TRAVEL FEEL With the vehicle in NEUTRAL, position it on a hoist. Refer to «JACKING & LIFTING»(ref-517532) . Ignition OFF. Raise the vehicle until the front wheels no longer touch the ground. Rotate the steering wheel from lock-to-lock and inspect the steering rack travel for the following: Abnormal noises Rough spots Sticky spots Tight spots Is steering rack travel smooth and free of any abnormal noises, rough, sticky and tight spots? Yes: No: Go to F4 . Go to F3.
F3: INSPECT THE INNER TIE RODS AND STEERING RACK FOR CORROSION NOTE: When installing new bellows boots and clamps apply new lubricant as instructed to prevent water contamination or damage may result to the electronic power assist steering (EPAS) gear. For complete information refer to the «Tie Rod - Inner»(ref-517538-S31843199942012121200000) . Remove the outer tie rod and bellows boot. Refer to «Tie Rod - Inner»(ref-517538-S31843199942012121200000) . The following inspection must be carried out on BOTH sides of the steering rack: Turn the steering wheel in one direction all the way until it stops to expose the steering rack. Inspect the rack, inner tie rod and gear housing for rust, moisture, corrosion and other signs of harmful contamination. Is the rack, inner tie rod and gear housing free of moisture, rust, corrosion and other harmful contamination? Yes: No: No fault found. The condition which caused the concern is not present at this time. The condition may have been caused by under-inflated tires. INSTALL new bellows boots with new clamps and install the removed outer tie rods. REFER to «Tie Rod - Inner»(ref-517538-S31843199942012121200000) . ADJUST the front toe setting. REFER to «TOE ADJUSTMENT - FRONT»(ref-517539-S03148492392012121200000) . INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) .
F4: TEST DRIVE TO CHECK FOR RETURNING DTCS Clear the PSCM DTCs. Cycle the ignition to OFF and then back to RUN. NOTE: Always drive the vehicle in a safe manner according to driving conditions and obey all traffic laws. Test drive the vehicle in the following manner: With the engine running/ready, stop the vehicle on an unsealed concrete or asphalt surface (in order to provide adequate friction for a thorough test). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. NOTE: The next portion of the test drive will require the vehicle to be driven at highway speeds. NOTE: The test period is a cumulative time of 10 minutes. Stopping, going slower than 72 km/h (45 mph) or faster that 96 km/h (60 mph) will not affect the test as long as a total time of 10 minutes is spent between 72-96 km/h (45-60 mph) with at least 4 lane changes during that time/speed window. Continue test driving the vehicle in the following manner: Bring the vehicle to a minimum speed of 72 km/h (45 mph), maximum of 96 km/h (60 mph). Maintain that speed for at least 10 minutes. During this 10-minute time period, make a minimum of 4 lane changes or turns that achieve a steering wheel angle of at least 20 degrees. The test drive is complete. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions. Is DTC P07AE:09 present? Yes No INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . The condition to set the DTC is not present at this time. RETURN the vehicle to the customer. For all other PSCM DTCs, REFER to the «DTC Index - Power Steering Control Module (PSCM)»(ref-517538-S38313120542013021300000) .

With a fully charged battery and the ignition ON, the electronic power assist steering (EPAS) system should provide adequate assist to maneuver the vehicle and should be able to return to the straight-ahead position with little difficulty. The assist provided by the EPAS system should be smooth and consistent at all times. The steering and suspension components should be free of any binding conditions and should not interfere with the steering assist provided by the EPAS system.

If the steering wheel is held at lock end for more than 2 seconds the EPAS system will reduce assist noticeably. This is a normal condition programmed into the power steering control module (PSCM) to protect the system from permanent damage.

I1: CHECK CHARGING SYSTEM VOLTAGE Ignition ON, engine running. With the vehicle running, turn the steering wheel from lock to lock and take the voltage measurement while holding the wheel in a lock position. Measure the voltage between: (+) 12 Volt Vehicle Battery (-) 12 Volt Vehicle Battery Positive terminal Negative terminal Turn the steering wheel from lock to lock with the vehicle running and note the PID reading while holding the wheel in a lock position. Access the PSCM and monitor the MOD_SUP_V (VOLT) PID. Is the battery voltage greater than 13 volts and does the PID match battery voltage +/- 1.5 volts? Yes: No: Go to I2. Go to A4 .
I2: CHECK THE EPAS GEAR With the vehicle in NEUTRAL, position it on a hoist. Refer to «JACKING & LIFTING»(ref-517532) . Isolate the steering gear from the steering knuckles. NOTE: Do not disconnect the steering gear from the steering column. Turn the steering wheel through the full range of motion (lock-to-lock) Is the binding condition still present? Yes: No: Go to I3. The condition may be caused by tires, wheel knuckles and/or ball joints. ISOLATE the component(s) causing the binding. INSTALL new component(s) as necessary. DRIVE the vehicle to VERIFY the repair.
I3: CHECK THE STEERING COLUMN SHAFT AND DASH SEAL While turning the steering wheel, check for binding conditions between the moving components of the steering column and the vehicle body and steering column shroud(s). Steering wheel rubbing against steering column shrouds. Binding steering column shaft dash panel seal Has a binding condition been identified? Yes: No: ISOLATE the component(s) causing the binding. INSTALL new component(s) as necessary. REFER to «STEERING COLUMN»(ref-517558-S06636659092012121200000) . DRIVE the vehicle to VERIFY the repair. Go to I4.
I4: CHECK THE STEERING GEAR Using a suitable steering wheel holding device, hold the steering wheel in the straight ahead position. Disconnect the steering gear from the steering column. Check the steering gear for correct installation, tight spots and uneven operation. Is the binding condition still present? Yes: No: INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . DRIVE the vehicle to VERIFY the repair. ISOLATE the component(s) that is causing the binding. INSTALL a new component(s) as necessary. REFER to Steering Column Shaft in «STEERING COLUMN SHAFT»(ref-517558-S05559042422012121200000) . DRIVE the vehicle to VERIFY the repair.
I5: CHECK THE STEERING GEAR With the vehicle in NEUTRAL, position it on a hoist. Refer to «JACKING & LIFTING»(ref-517532) . Isolate the steering gear from the steering knuckles. NOTE: Do not disconnect the steering gear from the steering column. Turn the steering wheel through the full range of motion (lock-to-lock) Is the binding condition still present? Yes: No: Go to I6. ISOLATE the component(s) causing the binding. INSTALL new component(s) as necessary.
I6: CHECK THE STEERING COLUMN FOR BINDING CONDITIONS While turning the steering wheel, check for binding conditions between the moving components of the steering column and the vehicle body and steering column shroud(s). Steering wheel rubbing against steering column shrouds. Binding steering column shaft dash panel seal Has a binding condition been identified? Yes: No: ISOLATE the component(s) causing the binding. INSTALL new component(s) as necessary. Go to I7.
I7: CHECK THE STEERING GEAR NOTE: The steering column must be locked in the straight ahead position using the service bolt (HB1), before the column is disconnected from the steering gear to prevent damage to the EPAS sensor internal clock-spring. Make sure that the steering wheel is set to the straight ahead position. Lock the steering column using the service bolt. REFER to «SPECIFICATIONS»(ref-517538-S09342956152012121200000) . Disconnect the steering gear from the steering column. Check the steering gear for correct installation, tight spots and uneven operation. Check the steering column U-joints for binding and uneven movement. Has a binding condition been identified? Yes: No: For Steering column shaft U-joints: INSTALL a new steering column shaft. REFER to «STEERING COLUMN SHAFT»(ref-517558-S05559042422012121200000) . For Steering gear: INSTALL a new steering gear as necessary. REFER to «Steering Gear»(ref-517538-S03013328262012121200000) . INSTALL a new EPAS assembly. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) .

The tie rods connect the electronic power assist steering (EPAS) gear to the wheel knuckles. There should be very little to no vertical or lateral movement in the inner and outer tie rod studs/sockets. Some rotational movement is acceptable.

J1: CHECK THE INNER AND OUTER TIE RODS FOR MOVEMENT With the vehicle in NEUTRAL, position it on a hoist. Refer to «JACKING & LIFTING»(ref-517532) . NOTE: When installing new bellows boots and clamps, apply new lubricant as instructed to prevent water contamination or damage may result to the EPAS gear. For complete information refer to the «Tie Rod - Inner»(ref-517538-S31843199942012121200000) . Using hand force only, check the inner and outer tie rods for vertical and lateral movement in the tie-rod ball studs/sockets. Are the inner and outer tie rods free from any vertical and/or lateral movement? Yes: No: The condition may be caused by wheel/tire runout. REFER «WHEELS & TIRES»(ref-517542) to Diagnosis and Testing . INSTALL a new inner or outer tie rod as necessary. REFER to «Tie Rod - Inner»(ref-517538-S31843199942012121200000) .

The electric power assist steering (EPAS) gear is very susceptible to water, moisture, dust, rust and other contaminates. If a damaged boot is suspected the inner tie rods and steering rack should be inspected for contamination. If contamination is found a new EPAS gear should be installed.

New bellows boots and clamps must be installed whenever they are removed. To avoid unnecessary repairs address all other known concerns, DTCs and customer concerns before removing the bellows boots and inspecting the steering gear.

Note. When installing new bellows boots and clamps, apply new lubricant as instructed to prevent water contamination or damage may result to the EPAS gear. For complete information refer to the Tie Rod - Inner .

K1: INSPECT THE INNER TIE RODS AND STEERING RACK FOR CORROSION Remove the outer tie rod and bellows boot. Refer to «Tie Rod - Inner»(ref-517538-S31843199942012121200000) . The following inspection must be carried out on BOTH sides of the steering rack: Turn the steering wheel in one direction all the way until it stops to expose the steering rack. Inspect the rack, inner tie rod and gear housing for rust, moisture, corrosion and other signs of harmful contamination. Is the rack, inner tie rod and gear housing free of moisture, rust, corrosion and other harmful contamination? Yes: No: INSTALL a new steering gear boot bellows. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) . ADJUST the front toe setting. REFER to «TOE ADJUSTMENT - FRONT»(ref-517539-S03148492392012121200000) . INSTALL a new EPAS gear. REFER to «REMOVAL AND INSTALLATION»(ref-517538-S01068877772012121200000) .

The power steering control module (PSCM) monitors various inputs and outputs of the electronic power assist steering (EPAS) system in order to keep the system operating at peak capacity. Information provided by sensors (steering torque, vehicle speed, vehicle travel distance, etc.) are all compared to programmed and learned information. Likewise, outputs like the motor and steering wheel position are tested against programmed and learned information.

M1: CHECK FOR PREVIOUSLY SET DTCS Go to «KNOWN CONCERNS»(ref-517538-S14122661412013021300000) . Check for DTCs listed in the System Related CMDTCs cleared since initial read. Are any of the following DTCs present? PSCM DTCs, U0300:00, U2011:49, U2011:61, U3000:05, U3000:41, U3000:43, U3000:44, U3000:46, U3000:49, U3000:61, U3000:96, C1B00:2F, C1B00:61, C1B00:62, C200B:2F, C200B:61, C200B:62, C200C:2F, C200D:49. Yes: No: INSTALL a new EPAS column assembly. REFER to «STEERING COLUMN»(ref-517558) . Go to M2.
M2: FAULT CONFIRMATION Ignition OFF. Wait 90 seconds for the module to exit the active state. Ignition ON, engine OFF. Clear the PSCM DTCs. Ignition OFF. Wait 90 seconds for the module to exit the active state. Ignition ON, engine running. Test drive the vehicle in the following manner: With the engine running/ready, stop the vehicle on an unsealed concrete or asphalt surface (in order to provide adequate friction for a thorough test). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. Return the steering wheel to the center position and move the vehicle forward approximately 32 cm (1 ft). With the vehicle in gear and the brakes applied, turn the steering wheel lock-to-lock. The test drive is complete. Ignition ON, engine OFF. Carry out the PSCM self-test. Are DTCs C1B00-2f, C1B00-61, C1B00-62, C200B-61, C200B-62, C200B-2f, C200C-2f, C200D-49, U0300, U2011-49, U2011-61, U3000-5, U3000-41, U3000-43, U3000-44, U3000-46, U3000-49 or U3000-96 present? Yes: No: INSTALL a new EPAS column assembly. REFER to «STEERING COLUMN»(ref-517558) . The condition to set the DTC is not present at this time. RETURN the vehicle to the customer.

Note. Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

Scheme 5

Scheme 5: Normal Operation

Circuit	Pin
B+ (Battery Positive Voltage) - SBF05	1(GRAY/RED)

Harness Side

Scheme 6

Circuit

Harness Side

N1: RETRIEVE ALL CMDTCS FROM ALL MODULES Ignition ON, engine running. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions. Is the PCM AND at least one other module in addition to the PSCM reporting charging system and/or battery voltage DTCs? Yes No REFER to «CHARGING SYSTEM»(ref-517537) to diagnose the battery and charging system. Go to N2.
N2: CHECK THE CONDITION OF THE BATTERY Ignition OFF. REFER to «BATTERY, BATTERY MOUNTING & BATTERY CABLES»(ref-517589) , Diagnosis and Testing, and implement Pinpoint Test A: Battery - Condition Test. Does the battery pass the condition test? Yes: No: Go to N3. INSTALL a new 12-volt battery. CLEAR the DTCs. REPEAT the self-test.
N3: CHECK THE BATTERY STATE OF CHARGE Review the results from the battery condition test. Did the battery require a recharge? Yes: No: REFER to «CHARGING SYSTEM»(ref-517537) to diagnose the battery and charging system. Go to N4.
N4: CHECK CHARGING SYSTEM VOLTAGE Ignition ON, engine running. Turn off all accessories. Measure the voltage between: (+) 12 Volt Vehicle Battery (-) 12 Volt Vehicle Battery Positive terminal Negative terminal Turn the headlamps on and set the HVAC fan to high. Measure the voltage between: (+) 12 Volt Vehicle Battery (-) 12 Volt Vehicle Battery Positive terminal Negative terminal Are the voltages between 13 and 15.2 volts? Yes: No: Go to N5. REFER to «CHARGING SYSTEM»(ref-517537) to diagnose the battery and charging system.
N5: CHECK THE PSCM MODULE VOLTAGE SUPPLY (MOD_SUP_V) PID Turn the steering wheel slowly from lock to lock and monitor the PID value displayed on the screen. Note the lowest PID reading value displayed while cycling the steering lock to lock. Access the PSCM and monitor the MOD_SUP_V (VOLT) PID. Does the lowest PID value displayed match the loaded battery voltage +/- 1.5 volts? Yes: No: An intermittent fault may be present in the wiring harness. Visually check for chaffed wires or other physical damage to the harness. If no fault is found in the circuit, suspect the following component(s): PSCM_A Connector PSCM_B Connector PSCM_C Connector To gain access to the EPAS electrical connectors, the knee air bag module will need to be removed. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM -- EXPLORER»(ref-517622) for additional information. CLEAR the DTCs. REPEAT the self-test. Go to N6.
N6: CHECK HIGH-CURRENT BJB FUSE 2 (60A) Ignition OFF. Check the condition of high-current BJB fuse 2 (60A), attached to the battery positive terminal. Check the fuse connection for security, damage and corrosion. Is the fuse in good condition and the fuse connection secure and free from damage or contamination? Yes: No: Go to N7. Loose electrical connection. CLEAN and TIGHTEN the electrical connection. To gain access to the EPAS electrical connectors, the knee air bag module will need to be removed. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(ref-517622) for additional information. CLEAR the DTCs. REPEAT the self-test. Blown fuse. Install a new fuse. CLEAR the DTCs. REPEAT the self-test.
N7: CHECK THE PSCM BATTERY VOLTAGE INPUT CIRCUIT FOR AN OPEN NOTE: To gain access to the EPAS electrical connectors, the knee air bag module will need to be removed. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(ref-517622) for additional information. PSCM_A connector disconnected. (C1463A) High-current Battery Junction Box connector disconnected. Measure the resistance between: (+) High-current Battery Junction Box Connector, Harness Side (-) PSCM_A (C1463A) Connector, Harness Side B+ B+ - SBF05 - Pin 1 Is the resistance less than 5 Ohm? Yes: No: Go to N8. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
N8: CHECK THE PSCM GROUND Inspect ground G200 for looseness and corrosion. Are the ground bolt and eyelet tight and free from any corrosion? Yes: No: REPAIR the open circuit. INSPECT the PSCM connectors for corrosion, spread terminals and pushed-out terminals. REPAIR as necessary. To gain access to the EPAS electrical connectors, the knee air bag module will need to be removed. REFER to «SUPPLEMENTAL RESTRAINT SYSTEM»(ref-517622) for additional information. If the connectors are okay, REPAIR the PSCM ground circuit. CLEAR the DTCs. REPEAT the self-test. CLEAN and TIGHTEN ground connection. CLEAR the DTCs. REPEAT the self-test.

The PSCM continually monitors and adjusts steering efforts based on the torque sensor inputs to enhance feel of the steering system. Compensation is made to reduce the effect of pull or drift that may be experienced when driving on roads with a high degree of camber. If the level of compensation required to keep the vehicle driving straight ahead exceeds a pre set level a DTC will be set.

O1: VISUAL INSPECTION Carry out a visual inspection. Check for even tire sizes and pressures as per the manufacturer's specification. Check for uneven tire wear. Check the outer tie rod ends and suspension ball joints for impeded movement. Verify that the steering column shaft rotates freely and is not grounded against other vehicle components. Check the steering gear for correct installation, tight spots and uneven operation. Check the steering and suspension for bent or damaged components. Check the steering and suspension geometry. Has a concern been identified? Yes: No: REPAIR the concern identified during the visual inspection. CLEAR the DTCs. CARRY OUT the steering angle sensor calibration procedure. REFER to PROGRAMMABLE PARAMETERS/STEERING WHEEL POSITION SENSOR CALIBRATION on the IDS and follow the calibration procedure. CLEAR the DTCs. CARRY OUT the steering angle sensor calibration procedure. REFER to PROGRAMMABLE PARAMETERS/STEERING WHEEL POSITION SENSOR CALIBRATION on the IDS and follow the calibration procedure.

The steering wheel position must be calibrated to the straight ahead position after installation of a new steering column, a new steering column intermediate shaft, repairs to the vehicle suspension or adjustment of the vehicle steering and suspension geometry.

P1: STEERING ANGLE SENSOR CALIBRATION Ignition ON, engine running. Turn the steering wheel approximately thirty degrees in each direction, then return to the central position. Make sure that the steering wheel is set to the straight ahead position. Ignition ON, engine OFF. With the vehicle stationary run the steering angle sensor calibration procedure. REFER to PROGRAMMABLE PARAMETERS/STEERING WHEEL POSITION SENSOR CALIBRATION on the IDS and follow the calibration procedure. Clear the PSCM DTCs. Ignition OFF. Wait 90 seconds for the module to exit the active state. Ignition ON, engine OFF. Carry out the PSCM self-test. Are DTCs C1B00-95 or C1B00-54 present? Yes: No: INSTALL a new EPAS assembly. The customers concern has been corrected.

The tie rods connect the steering gear to the wheel knuckles. There should be very little to no vertical or lateral movement in the inner and outer tie rod studs/sockets. Some rotational movement is acceptable.

Q1: CHECK THE INNER AND OUTER TIE RODS FOR MOVEMENT With the vehicle in NEUTRAL, position it on a hoist. Refer to «JACKING & LIFTING»(ref-517532) . Using hand force only, check the inner and outer tie rods for vertical and lateral movement in the tie-rod ball studs/sockets. Are the inner and outer tie rods free from any vertical and/or lateral movement? Yes: No: Go to Q2. INSTALL a new inner or outer tie rod as necessary. REFER to «Tie Rod - Inner»(ref-517538-S31843199942012121200000) .
Q2: CHECK THE SUSPENSION BALL JOINTS AND BUSHINGS FOR DAMAGE, SECURITY, EXCESSIVE FREE PLAY AND IMPEDED MOVEMENT Check the suspension ball joints and bushings for damage, security, excessive free play and impeded movement. Has a concern been identified? Yes: No: REPAIR as necessary. The condition may be caused by wheel/tire runout. REFER to Diagnosis and Testing, «WHEELS & TIRES»(ref-517542) .

T1: VISUAL INSPECTION Carry out a visual inspection. Check for even tire sizes and pressures as per the manufacturer's specification. Check for uneven tire wear. Check the outer tie rod ends and suspension ball joints for impeded movement. Verify that the steering column shaft rotates freely and is not grounded against other vehicle components. Check the steering gear for correct installation, tight spots and uneven operation. Check the steering and suspension for bent or damaged components. Check the steering and suspension geometry. Has a concern been identified? Yes: No: REPAIR the concern identified during the visual inspection. CLEAR the DTCs. Using the scan tool, RESET the compensation value for the pull/drift compensation function and the compensation value for the steering straight ahead position. TEST the system for normal operation. CLEAR the DTCs. Using the scan tool, RESET the compensation value for the pull/drift compensation function and the compensation value for the steering straight ahead position. TEST the system for normal operation.

The SASM broadcasts the absolute steering angle value to the PSCM over the HS-CAN at predefined intervals during every drive cycle from the first ignition ON status. During normal operation the absolute steering angle from the SASM is compared against a steering angle derived from the rear wheel speed values broadcast by the ABS module over the HS-CAN and an angle derived from the EPAS motor position. If the absolute steering angle values and the derived steering angles do not match, the EPAS system will set to a default level of assistance.

U1: CHECK FOR SASM DTCS Ignition ON, engine OFF. Press Read Vehicle Information button to retrieve DTC s from the vehicle. NOTE: DTCs may be displayed from previous diagnostic actions. Are any SASM DTCs present? Yes No REFER to «ANTI-LOCK BRAKE SYSTEM AND STABILITY CONTROL»(ref-517557) to diagnose the SASM concern. Go to U2.
U2: CHECK THE SASM FOR CORRECT INSTALLATION Check the SASM for correct installation. Refer to «ANTI-LOCK BRAKE SYSTEM AND STABILITY CONTROL»(ref-517557) . Make sure that the steering wheel is set to the straight ahead position. Access the PSCM and monitor the SW_ANGLE (ANGL) PID. Is the angle between -4 deg - 4 deg? Yes: No: The condition to set the DTC is not present at this time. CLEAR the DTCs. TEST the system for normal operation. CHECK the SASM for correct installation. REFER to «ANTI-LOCK BRAKE SYSTEM AND STABILITY CONTROL»(ref-517557) .

Electronic Power Assist Steering: Overview Ford Explorer V

Overview

Scheme 1

Principles of Operation

Scheme 2

Scheme 3

Description

Normal Operation

Scheme 4

Scheme 5

Scheme 6

More articles — Electronic Power Assist Steering

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