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Contents Section: Manual & Power Steering All sections

Steering System Mercury Mariner II рестайлинг

Manual & Power Steering 13 illustrations ~5579 words

Electronic Power Assist Steering (EPAS) System

The Electronic Power Assist Steering (EPAS) system consists of the following components

  1. Power Steering Control Module (PSCM) - the PSCM controls the functions of the EPAS system and communicates with other modules that are on the High Speed Controller Area Network (HS-CAN) bus. The PSCM is attached to the EPAS column assembly and is not available separately for service.
  2. Motor - the EPAS gear uses a 12-volt brushless, reversible motor, a worm gear and a reduction gear to control the steering effort. The motor is attached to the EPAS column assembly and is not available separately for service.
  3. Steering sensor - the steering sensor is used by the PSCM to determine force applied to, speed and direction of the steering wheel. This information is transmitted to other modules along the HS-CAN bus. The sensor is attached to the EPAS column assembly and is not available separately for service.
  4. Steering column shaft - the steering column shaft connects the EPAS column assembly to the steering gear and is available separately for service. Refer to «STEERING COLUMN»(/mercury/mariner/ii-2011-2011/remont/steering-column/#steering-column) article.
  5. Steering gear - the steering gear is a rack and pinion type gear, which is serviced as an assembly and is contained within a one-piece aluminum housing. The steering gear uses tie-rod ends to connect the gear to the wheel knuckles. The steering gear can be serviced separately from the EPAS column assembly, refer to «POWER STEERING»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#power-steering-system) article.
  6. Tie-rod ends - one inner and outer tie rod is located at each end of the steering gear and are available separately for service. Refer to «POWER STEERING»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#power-steering-system) article.

The EPAS system provides power steering assist to the driver by replacing the conventional hydraulic valve system with an electric motor coupled to the steering shaft. The motor is controlled by the PSCM which senses the steering effort through the use of a sensor mounted between the steering column shaft and the steering gear. Steering assist is provided in proportion to the steering input effort and vehicle speed.

Active Park Assist

Some vehicles may also be equipped with active park assist. The active park assist system is controlled by the Parking Aid Module (PAM) and, when activated, can detect a parking space and steer the vehicle into the space by sending commands to the PSCM (the driver still controls the throttle, brakes and transmission). The active park assist system is comprised of several systems/modules that work together to aid in parallel parking maneuvers, the presence of certain DTCs in any of those systems/modules may keep the active park assist system from being enabled or may disable the system if currently being used. Refer to ACTIVE PARK ASSIST article for additional information on active park assist.

Special Tool(s)

SPECIAL TOOLS Flex Probe Kit 300-NUD105-R025DE or equivalent Fluke 77-IV Digital Multimeter FLU77-4 or equivalent Tie-Rod End Remover 211-001 (TOOL-3290-D) Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool

Scheme 1

Scheme 1: Special Tool(s)
Scheme 1: Special Tool(s)

Electronic Power Assist Steering (EPAS)

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 shaft. The motor is controlled by the Power Steering Control Module (PSCM) that senses the steering effort through the use of a torque sensor mounted between the steering column shaft and 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 hardwired 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.

The vehicle speed, which is sent by the PCM over the HS-CAN bus, provides the necessary information to the EPAS to determine the amount or level of power assist. As vehicle speed increases, the amount of power assist provided by the system is reduced to improve and enhance road feel at the steering wheel. If the vehicle speed is missing or out of range, the PSCM defaults to a reduced level of assist. If the vehicle speed returns to the correct in-range values, the PSCM adjusts the steering assist level accordingly.

Low battery and/or charging system voltage or a charging system DTC being present may cause the PSCM to enter into a limited operation mode resulting in uneven steering assist or a lack of steering assist. This limited operation mode feature is built into the PSCM to allow the safe, continued operation of the vehicle in the event of an EPAS concern. A DTC may or may not be preset when the PSCM is operating in limited operation mode. Additionally, overheating the steering system may cause the PSCM to go into the limited operation mode, this is in order to protect the electronic components from overheating.

Power Steering Control Module (PSCM)

The PSCM manages the EPAS system. The PSCM receives vehicle speed information from the PCM via the HS-CAN bus, the module also receives information from the steering shaft torque sensor to determine the amount of assist that is needed. At lower speeds, the control module will provide greater assist. At higher speeds, the control module will provide less assist. The PSCM is part of the steering column and is not serviceable separately.

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" and will provide a set amount of assist to the EPAS system.

Power Steering Motor

The EPAS system uses a 12-volt brushless reversible motor to control the steering effort. The motor is connected to the steering shaft through a worm gear and a reduction gear on the steering column. The motor is part of the steering column assembly and is not serviceable separately.

Steering Sensor

The steering sensor provides the PSCM with information on the direction, speed and amount of force being applied to the steering wheel. The module uses this information to determine the amount of steering assist required. The sensor is a 5-volt dual analog sensor with an output voltage range of 0.25 volt to 4.75 volts. When the steering wheel is turned to the left, the left signal increases while the right signal decreases, likewise when the steering wheel is turned to the right, the right signal increases while the left signal decreases.

Electronic Power Assist Steering (EPAS) Column Assembly Initialization

After installing a new EPAS steering column assembly, the steering column assembly must be configured and the steering wheel position sensor must be calibrated. Refer to STEERING WHEEL POSITION SENSOR CALIBRATION in this service information.

Electronic Power Assist Steering (EPAS) Column Assembly Configuration

Refer to Programmable Module Installation (PMI) in MODULE CONFIGURATION article.

When the active park assist system is enabled, the Parking Aid Module (PAM) will utilize ultrasonic sensors to locate and measure a parking space. Once a parking space is identified by the system and accepted by the driver, the PAM will send steering command messages to the PSCM over the HS-CAN bus. The PSCM will utilize steering angle information and wheel speed sensor information (wheel speed is transmitted by the ABS module over the HS-CAN bus) to actuate the steering system as requested by the PAM .

Any driver inputs via the steering wheel will deactivate the active park assist system. Also, the presence of certain DTCs in the PSCM , PAM and/or ABS module will disable the system or keep the system from being activated. Refer to ACTIVE PARK ASSIST article for additional information on the active park assist system.

Inspection and Verification

  1. Verify the customer concern.
  2. Visually inspect for obvious signs of mechanical or electrical damage. VISUAL INSPECTION CHART Mechanical Electrical Binding or misaligned steering column Loose steering column shaft bolts Steering column shaft coupling/U-joints Steering gear Suspension components Tie-rod ends Tire pressure Tires Battery Junction Box (BJB) 80A MIDI (WH) fuse PCM Power Steering Control Module (PSCM) Smart Junction Box (SJB) fuse 35 (10A) SJB Wiring, terminals or connectors
  3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
  4. If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).
  5. If the scan tool does not communicate with the VCM : check the VCM connection to the vehicle. check the scan tool connection to the VCM . refer to «MODULE COMMUNICATIONS NETWORK»(/mercury/mariner/ii-2011-2011/remont/communication-devices/#module-communications-network) article, No Power To The Scan Tool, to diagnose no power to the scan tool.
  6. If the scan tool does not communicate with the vehicle: verify the ignition key is in the ON position. verify the scan tool operation with a known good vehicle. refer to «MODULE COMMUNICATIONS NETWORK»(/mercury/mariner/ii-2011-2011/remont/communication-devices/#module-communications-network) article to diagnose no response from the PCM.
  7. Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to «MODULE COMMUNICATIONS NETWORK»(/mercury/mariner/ii-2011-2011/remont/communication-devices/#module-communications-network) article. If the network test passes, retrieve and record Continuous Memory Diagnostic Trouble Codes (CMDTCs).
  8. Clear the continuous DTCs and carry out the self-test diagnostics for the PSCM .
  9. If the DTCs retrieved are related to the concern, go to the «POWER STEERING CONTROL MODULE (PSCM) DTC CHART»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-system__power-steering-control-module-pscm-dtc) . For all other DTCs, refer to «MULTIFUNCTION ELECTRONIC MODULE»(/mercury/mariner/ii-2011-2011/remont/communication-devices/#multifunction-electronic-module) article.
  10. If no DTCs related to the concern are retrieved, Go to «SYMPTOM CHART - STEERING SYSTEM»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-system) or Go to «SYMPTOM CHART - NVH»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-system__symptom-chart-nvh) .

Power Steering Control Module (PSCM) DTC Chart

DTCsDescriptionAction
B1317Battery Voltage HighGo to PINPOINT TEST A .
B1318Battery Voltage LowGo to PINPOINT TEST A .
B1342ECU is FaultedINSTALL a new steering column. Refer to STEERING COLUMN article.
B2277Electric Power Steering Motor MalfunctionINSTALL a new steering column. Refer to STEERING COLUMN article.
B2278Steering Shaft Torque Sensor MalfunctionINSTALL a new steering column. Refer to STEERING COLUMN article.
B2477Module Configuration FailureCONFIGURE the PSCM . Refer to Programmable Module Installation (PMI) in MODULE CONFIGURATION article. CALIBRATE the steering wheel position sensor. Refer to STEERING WHEEL POSITION SENSOR CALIBRATION in this service information. CLEAR the DTCs. REPEAT the self-test. If DTC B2477 is retrieved again, INSTALL a new steering column. Refer to STEERING COLUMN article. REPEAT the self-test.
B227BSteering Shaft Position Sensor MalfunctionINSTALL a new steering column. Refer to STEERING COLUMN article.
C195CElectronic Power Assist Limited Operation Mode DetectedGo to PINPOINT TEST D
C2000Steering Angle Sensor Not CalibratedCALIBRATE the steering wheel position sensor. Refer to STEERING WHEEL POSITION SENSOR CALIBRATION this service information. CLEAR the DTCs. REPEAT the self-test. If DTC C2000 is retrieved again, INSTALL a new steering column. Refer to STEERING COLUMN article. REPEAT the self-test.
P0635Power Steering Control CircuitThis DTC indicates that the steering request made by the Parking Aid Module (PAM) exceeds the physical limits of the steering system. CHECK the front toe settings. Refer to Toe Adjustment in SUSPENSION SYSTEM - GENERAL INFORMATION article. ADJUST as necessary. If the front toe settings are OK, CALIBRATE the steering wheel position sensor. Refer to STEERING WHEEL POSITION SENSOR CALIBRATION in this service information. CLEAR the DTC. Carry out a self test of the PSCM . If the DTC returns, Carry out a self test of the PAM . Refer to ACTIVE PARK ASSIST article. If there are no DTCs in the PAM , INSTALL a new steering column. Refer to STEERING COLUMN article.
P1653Power Steering Output CircuitThis DTC indicates that the difference between the steering angle request made by the Parking Aid Module (PAM) and the actual steering angle measured by the PSCM exceed a preset limit. CALIBRATE the steering wheel position sensor. Refer to STEERING WHEEL POSITION SENSOR CALIBRATION in this service information. CLEAR the DTC. Carry out a self test of the PSCM . If the DTC returns, Carry out a self test of the PAM . Refer to ACTIVE PARK ASSIST article to diagnose any DTCs. If there are no DTCs in the PAM , INSTALL a new steering column. Refer to STEERING COLUMN article.
U0100Lost Communication With ECM/PCMREPAIR all other DTCs first. If DTC U0100 is still present, Refer to MODULE COMMUNICATIONS NETWORK article to diagnose the High Speed Controller Area Network (HS-CAN) bus.
U0101Lost Communication With TCMREPAIR all other DTCs first. If DTC U0101 is still present, Refer to MODULE COMMUNICATIONS NETWORK article to diagnose the HS-CAN bus.
U0121Lost Communication With ABSREPAIR all other DTCs first. If DTC U0121 is still present, Refer to MODULE COMMUNICATIONS NETWORK article to diagnose the HS-CAN bus.
U0155Lost Communication With Instrument Panel ClusterREPAIR all other DTCs first. If DTC U0155 is still present, Refer to MODULE COMMUNICATIONS NETWORK article to diagnose the HS-CAN bus.
U0159Lost Communication With Parking Assist Control ModuleREPAIR all other DTCs first. If DTC U0159 is still present, Refer to MODULE COMMUNICATIONS NETWORK article to diagnose the HS-CAN bus.
U0402Invalid Data Received from TCMThis DTC indicates that the PSCM has received an "invalid data" message from the TCM . The TCM is part of the PCM. RETRIEVE and RECORD all DTCs from the PCM. Refer to the INTRODUCTION article to diagnose the DTCs.
U0415Invalid Data From ABSVERIFY the correct PSCM configuration. VERIFY that the correct Vehicle Identification Number (VIN) is programmed to the PCM. Carry out the PCM self-test, RETRIEVE and RECORD any DTCs. Refer to the Diagnostic Trouble Code (DTC) Chart in MULTIFUNCTION ELECTRONIC MODULE article.
U045AInvalid Data From Parking Assist Control ModuleVERIFY the correct PSCM configuration. VERIFY that the correct VIN is programmed to the PCM. Carry out the PCM self-test, RETRIEVE and RECORD any DTCs. Refer to the Diagnostic Trouble Code (DTC) Chart in MULTIFUNCTION ELECTRONIC MODULE article.
U2023Fault Received From External NodeOne or more modules are reporting a DTC. RETRIEVE DTCs from all other modules. Refer to the module's respective service information for diagnosis. If no DTCs are present, Refer to MODULE COMMUNICATIONS NETWORK article to diagnose the HS-CAN bus.
U2499ECU Overheat ProtectionThe PSCM uses a thermistor to monitor the internal temperature of the EPAS gear. This DTC alone does not indicate a fault in the PSCM . It indicates an over-temperature condition due to ambient conditions and/or a heavy load on the EPAS system. DIAGNOSE all other PSCM DTCs before diagnosing DTC U2499. If no other DTCs are present, ADVISE the customer that high ambient temperatures and/or heavy loads on the EPAS system causes this DTC to set, resulting in higher than usual steering effort. A heavy load is defined as multiple parking lot maneuvers over a short duration of time, possibly with low tire pressure, or towing for long distances followed by multiple parking maneuvers.

DTC CHART

Steering System Symptom Definitions

Drift/Pull

Pull is described as a tugging sensation, felt by the hands on the steering wheel, that must be overcome to keep the vehicle going straight.

Drift describes what a vehicle with this condition does with the hands off the steering wheel.

  1. A vehicle-related drift/pull, on a flat road, can cause a consistent deviation from the straight-ahead path and require constant steering input in the opposite direction to counteract the effect.
  2. Drift/pull can be induced by conditions external to the vehicle (for example, wind or road camber).

Excessive Steering Wheel Play

Excessive steering wheel play is a condition in which there is too much steering wheel movement before the wheels move. A small amount of steering wheel free play is considered normal.

Lack of Assist or Inconsistent Assist

Lack of assist or inconsistent assist is experienced when the steering wheel effort is higher than normal. Hard steering can remain constant through the full turn or occur near the end of a turn. It is important to know the difference between hard steering/inconsistent assist and poor returnability/sticky steering.

Hard steering or lack of assist can result from either electrical or mechanical conditions.

Poor Returnability/Sticky Steering

Poor returnability and sticky steering is used to describe the poor return of the steering wheel to center after a turn or the steering correction, is completed.

Shimmy

Shimmy, as observed by the driver, is large, consistent, rotational oscillations of the steering wheel resulting from large, side-to-side (lateral) tire/wheel movements.

Shimmy is usually experienced near 64 km/h (40 mph), and can begin or be amplified when the tire contacts pot holes or irregularities in the road surface.

Wander

Wander is the tendency of the vehicle to require frequent, random left and right steering wheel corrections to maintain a straight path down a level road.

ConditionPossible SourcesAction
No communication with the Power Steering Control Module (PSCM)Wiring, terminals or connectors Fuse(s) PSCMRefer to MODULE COMMUNICATIONS NETWORK article to diagnose the no communication problem.
Excessive steering wheel playSteering column shaft/U-joints Steering linkage Steering gearGo to PINPOINT TEST B .
Steering system drift/pull/wanderSteering column shaft/U-joints Steering column Steering gear mounts Steering column torsion barGo to PINPOINT TEST C .
Poor returnability/sticky steeringBinding lower steering column shaft coupling/U-joints Loose, worn or damaged steering linkage Binding suspension components Binding steering gear Binding steering column bearing(s) Binding steering column shaft dash panel seal Steering wheel position sensor not calibrated Alignments/suspensionGo to PINPOINT TEST D .
Lack of assist or inconsistent assistSuspension components Steering components Wiring terminals or connectors Low battery/charging system voltageGo to PINPOINT TEST D .
The active park assist system does not activateDTCs present in PAM , PSCM and/or ABS module.RETRIEVE and RECORD all DTCs. DIAGNOSE all PAM DTCs before diagnosing any PSCM or ABS module DTCs. For PAM and ABS module DTCs, Refer to the Diagnostic Trouble Code (DTC) Chart in MULTIFUNCTION ELECTRONIC MODULE article. For PSCM DTCs, Refer to the POWER STEERING CONTROL MODULE (PSCM) DTC CHART in this service information.
The active park assist system deactivates during parking maneuversDriver input via steering wheelRefer customer to the active park assist service information of the Owner's Literature for correct system operation.
DTCs present in PAM , PSCM and/or ABS module.RETRIEVE and RECORD all DTCs. DIAGNOSE all PAM DTCs before diagnosing any PSCM or ABS module DTCs. For PAM and ABS module DTCs, Refer to the Diagnostic Trouble Code (DTC) Chart in MULTIFUNCTION ELECTRONIC MODULE article. For PSCM DTCs, Refer to the POWER STEERING CONTROL MODULE (PSCM) DTC CHART in this service information.

SYMPTOM CHART - STEERING SYSTEM

Symptom Chart - NVH

Note. NVH symptoms should be identified using the diagnostic tools that are available. For a list of these tools, an explanation of their uses and a glossary of common terms, refer to NOISE, VIBRATION & HARSHNESS article. Since it is possible any one of multiple systems may be the cause of a symptom, it may be necessary to use a process of elimination type of diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, refer back to NOISE, VIBRATION & HARSHNESS article for the next likely system and continue diagnosis.

ConditionPossible SourcesAction
Steering column pop or clunk - occurs with wheels 1/4 turn from stopsSteering column shaft/couplingREPLACE both the steering shaft and steering shaft coupling U-joint. Refer to STEERING COLUMN article.
Steering gear clunk - occurs only while cornering over a bump (can be temperature sensitive)Steering gear insulators or mounting bolts loose or damagedTIGHTEN the bolts to specification or INSTALL new bolts as necessary. Refer to POWER STEERING article.
Feedback (rattle, chuckle or knocking noise) - roughness is felt in the steering wheel when the vehicle is driven over rough surfacesSteering column shaft/coupling bolts are looseTIGHTEN the bolts to specification. Refer to STEERING COLUMN article.
Steering column shaft/coupling joints damaged or wornINSTALL a new steering column shaft. Refer to STEERING COLUMN article.
Loose, damaged or worn tie-rod endsINSPECT and INSTALL new tie-rod ends as necessary. Go to STEERING LINKAGE in this service information.
Steering gear insulators or mounting bolts loose or damagedTIGHTEN the bolts to specification or INSTALL new bolts as necessary. Refer to POWER STEERING article.
Steering column squeaks, clicks or grindsLoose or misaligned steering column shrouds Steering wheel rubbing against steering column shroudsTIGHTEN the steering column shroud screws or ALIGN the steering column shrouds.
Hiss or whistle while turning the steering wheelGrounded or loose steering column shaft dash panel sealNOTE: Some amount of noise from the Electronic Power Assist Steering (EPAS) column is considered acceptable. If in doubt of the acceptability, compare to another vehicle. REPAIR or INSTALL a new dash panel seal as necessary. Refer to Steering Column Shaft in STEERING COLUMN article.
ShimmyLoose, worn or damaged tie rodGo to STEERING LINKAGE in this service information.
Steering gear clunk - occurs at end of travel once per ignition cycleContact with the steering stopsThis is a normal characteristic of the system. Once EPAS determines center, the software is designed to increase steering effort near the hard stops to prevent the noise from occurring until the next ignition key cycle. Do not replace the steering column or steering gear for this concern.
NOTE
Some amount of noise from the Electronic Power Assist Steering (EPAS) column is considered acceptable. If in doubt of the acceptability, compare to another vehicle.

SYMPTOM CHART - NVH

Pinpoint Test A: DTCs B1317 and B1318

Refer to SYSTEM WIRING DIAGRAMS article, Power Steering Controls for schematic and connector information.

Normal Operation

The voltage required for correct Electronic Power Assist Steering (EPAS) system operation is 11-16 volts. Above or below that voltage range, DTC B1317 (battery voltage high) or DTC B1318 (battery voltage low) will be set.

Fused ignition voltage for the EPAS system is supplied to the control module by Smart Junction Box (SJB) fuse 35 (10A) along circuit CBP35 (YE/GY). Fused battery voltage for the power steering motor is supplied to the Power Steering Control Module (PSCM) by Battery Junction Box (BJB) 80A MIDI (WH) fuse along circuit SBB01 (RD). Ground for the PSCM is provided along circuit GD116 (BK/VT).

  1. DTC B1317 (Battery Voltage High) - When the battery or charging system voltage exceeds 16 volts for more than 1,000 ms, DTC B1317 will be set.
  2. DTC B1318 (Battery Voltage Low) - When the battery or charging system voltage drops below 9 volts for more than 4,000 ms, DTC B1318 will be set.
  3. These DTCs may also result in a reduced amount of steering assist.

This pinpoint test is intended to diagnose the following

  1. Wiring, terminals or connectors
  2. Charging system
  3. PSCM

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

Note. DTC B1317, B1318 or B1676 can be set if the vehicle has been recently jump started, the battery has been recently charged or the battery has been discharged. The battery may become discharged due to excessive load(s) on the charging system from aftermarket accessories or if the battery has been left unattended with the accessories on.

Note. Carry out a thorough inspection and verification before proceeding with the pinpoint test. Refer to INSPECTION AND VERIFICATION in this service information.

Scheme 2

Scheme 2: PINPOINT TEST A: DTCs B1317 AND B1318
Scheme 2: PINPOINT TEST A: DTCs B1317 AND B1318

Scheme 3

Scheme 3
Scheme 3

Scheme 4

Scheme 4
Scheme 4

Scheme 5

Scheme 5
Scheme 5
  1. A1 RETRIEVE ALL CMDTCs IN ALL MODULES Ignition ON. Enter the following diagnostic mode on the scan tool: Self Test - All CMDTCs . Is DTC B1317, B1318 or B1676 present in one or more modules AND is DTC P0563, P0620, P0625, P0626 or P065B present in the PCM? Yes: Refer to «CHARGING SYSTEM»(/mercury/mariner/ii-2011-2011/remont/charging-system/#charging-system) article for diagnosis of the battery and charging system. No: Go to A2 .
  2. A2 CHECK BATTERY CONDITION Ignition OFF. Refer to «BATTERY, BATTERY MOUNTING SYSTEM & BATTERY CABLES»(ref-434539) article and carry out Pinpoint Test A: Battery Condition Test. Does the battery pass the condition test? Yes: If the battery passed the condition test but required a recharge, Refer to «CHARGING SYSTEM»(/mercury/mariner/ii-2011-2011/remont/charging-system/#charging-system) article to diagnose the charging system. CLEAR all Continuous Memory Diagnostic Trouble Codes (CMDTCs). TEST the system for normal operation. If the battery passed the condition test and did not require a recharge, Go to A3 . No: INSTALL a new battery. CLEAR all CMDTCs . TEST the system for normal operation.
  3. A3 CHECK THE CHARGING SYSTEM VOLTAGE NOTE: Do not allow the engine rpm to increase above 2,000 rpm while performing this step or the generator may self excite and result in default charging system output voltage. If engine rpm has gone above 2,000 rpm, shut the vehicle OFF and restart the engine before performing this step. Start the engine. Measure the voltage of the battery: For DTC B1317, turn off all accessories and run the engine at 1,500 rpm for a minimum of 2 minutes. For DTC B1318, turn on headlights and HVAC fan on high and run engine at 1,500 rpm for a minimum of 2 minutes. Is the battery voltage between 13-15.2 volts? Yes: For DTC B1318, Go to A4 . For DTC B1317, Go to A7 . No: Refer to «CHARGING SYSTEM»(/mercury/mariner/ii-2011-2011/remont/charging-system/#charging-system) article to diagnose the charging system. CLEAR all CMDTCs . TEST the system for normal operation.
  4. A4 CHECK FOR IGNITION VOLTAGE AT THE PSCM Ignition OFF. Disconnect: PSCM C1463A. Ignition ON. Measure the voltage between PSCM C1463A-1, circuit CBP35 (YE/GY), harness side and ground. Is the voltage greater than 11 volts? Yes: Go to A5 . No: VERIFY SJB fuse 35 (10A) is OK. If OK, REPAIR circuit CBP35 (YE/GY). If not OK, Refer to the «SYSTEM WIRING DIAGRAMS»(ref-395046) article to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test.
  5. A5 CHECK FOR BATTERY VOLTAGE AT THE PSCM Disconnect: PSCM C1463B. Measure the voltage between PSCM C1463B-1, circuit SBB01 (RD), harness side and ground. Is the voltage greater than 11 volts? Yes: Go to A6 . No: REPAIR circuit SBB01 (RD). CLEAR the DTCs. REPEAT the self-test.
  6. A6 CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN Measure the resistance between PSCM C1463B-2, circuit GD116 (BK/VT), harness side and ground. Is the resistance less than 5 ohms? Yes: Go to A7 . No: REPAIR circuit GD116 (BK/VT). CLEAR the DTCs. REPEAT the self-test.
  7. A7 CHECK THE PSCM OPERATION Disconnect the PSCM connectors. Check the connectors for: corrosion. pushed-out pins. spread terminals. Connect the PSCM connectors and make sure that they are seated correctly. Operate the system and verify the concern is still present. Is the concern still present? Yes: INSTALL a new steering column. Refer to «STEERING COLUMN»(/mercury/mariner/ii-2011-2011/remont/steering-column/#steering-column) article. CLEAR the DTCs. REPEAT the self-test. No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

Pinpoint Test B: Excessive Steering Wheel Play

This pinpoint test is intended to diagnose the following

  1. Steering column shaft U-joints
  2. Steering linkage
  3. Steering gear
  1. B1 CHECK THE STEERING LINKAGE Carry out the «Steering Linkage»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-system__steering-linkage) Component Test in this service information. Is the steering linkage OK? Yes: Go to B2 . No: INSTALL new steering linkage components as necessary. Refer to the appropriate Steering System article for the procedure.
  2. B2 CHECK THE STEERING COLUMN SHAFT Inspect the steering column shaft U-joints and fasteners for looseness. Are the U-joints and fasteners OK? Yes: INSTALL a new steering gear as necessary. Refer to «POWER STEERING»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#power-steering-system) article. No: TIGHTEN the steering column shaft fasteners or INSTALL a new steering column shaft. Refer to «STEERING COLUMN»(/mercury/mariner/ii-2011-2011/remont/steering-column/#steering-column) article.

This pinpoint test is intended to diagnose the following

  1. Steering column shaft
  2. Steering gear
  3. Steering gear mounts
  4. Steering column shaft U-joints
  5. Steering column torsion bar
  1. C1 CHECK THE STEERING COLUMN SHAFT NOTE: Be sure to keep the clockspring centered when disconnecting the intermediate shaft. Refer to «SUPPLEMENTAL RESTRAINT SYSTEM»(ref-434537) article. Check the steering column and shaft for grounding. Disconnect the steering column shaft at the steering column. Inspect the steering column shaft U-joints for looseness or wear. Are the steering column shaft U-joints OK? Yes: Go to C2 . No: INSTALL new steering column shaft as necessary. Refer to «STEERING COLUMN»(/mercury/mariner/ii-2011-2011/remont/steering-column/#steering-column) article.
  2. C2 CHECK THE STEERING GEAR MOUNTING Check the steering gear mounts for looseness or wear. Are the steering gear mounts OK? Yes: Go to C3 . No: INSTALL a new steering gear as necessary. Refer to «POWER STEERING»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#power-steering-system) article.
  3. C3 CHECK THE STEERING GEAR Carry out the «Steering Column Torsion Bar Test»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-system__steering-column-torsion-bar-test) in this service information. Is the steering column OK? Yes: Refer to «SUSPENSION SYSTEM - GENERAL INFORMATION»(/mercury/mariner/ii-2011-2011/remont/suspension-front/#suspension-system-general-information) article to diagnose suspension system drift/pull/wander. No: INSTALL a new steering gear as necessary. Refer to «POWER STEERING»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#power-steering-system) article.

Pinpoint Test D: Poor Returnability/Sticky Steering, Steering Has a Lack of Assist or Inconsistent Assist and DTC C195C

Refer to SYSTEM WIRING DIAGRAMS article, Power Steering Controls for schematic and connector information.

With a fully charged battery and the ignition in the ON position, 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.

  1. DTC C195C (Electric Power Assist Limited Operation Mode Detected) - This DTC indicates that the voltage to the PSCM is below the normal operating range and is causing a perceived loss of steering assist.

The Power Steering Control Module (PSCM) will enter into a limited operation mode that may result in a lack of assist or inconsistent assist for the following reasons

  1. Battery and/or charging system voltage exceeds 16 volts.
  2. The charging system warning indicator is illuminated and battery/charging system voltage falls below 11.8 volts.
  3. The charging system warning indicator is not illuminated and battery/charging system voltage falls below 10.8 volts.

The limited operation mode is a fail-safe mode that will allow the continued, safe operation of the steering system in the event of a high/low voltage condition.

Fused ignition voltage for the EPAS system is supplied to the PSCM by Smart Junction Box (SJB) fuse 35 (10A) along circuit CBP35 (YE/GY). Fused battery voltage for the EPAS system motor is supplied to the control module by the Battery Junction Box (BJB) 80A MIDI fuse (WH) along circuit SBB01 (RD). Ground for the control module is provided along circuit GD116 (BK/VT). The PSCM communicates with the other vehicle modules along the High Speed Controller Area Network (HS-CAN) bus, circuits VDB04 (WH/BU) and VDB05 (WH).

This pinpoint test is intended to diagnose the following

  1. Fuse(s)
  2. Wiring, terminals or connectors
  3. Vehicle battery/charging system
  4. Steering wheel position sensor calibration
  5. Steering components
  6. Suspension components
  7. Steering column

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

Note. Carry out a thorough inspection and verification before proceeding with the pinpoint test. Refer to INSPECTION AND VERIFICATION in this service information.

Scheme 6

Scheme 6: PINPOINT TEST D: POOR RETURNABILITY/STICKY STEERING, STEERING HAS A LACK OF ASSIST OR INCONSISTENT A
Scheme 6: PINPOINT TEST D: POOR RETURNABILITY/STICKY STEERING, STEERING HAS A LACK OF ASSIST OR INCONSISTENT A

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8

Scheme 9

Scheme 9
Scheme 9

Scheme 10

Scheme 10
Scheme 10

Scheme 11

Scheme 11
Scheme 11

Scheme 12

Scheme 12
Scheme 12

Scheme 13

Scheme 13
Scheme 13
  1. D1 CHECK FOR CHARGING SYSTEM DTCs Connect the scan tool. Ignition ON. Enter the following diagnostic mode on the scan tool: Self Test - PCM. Are there any charging system DTCs present? Yes: Refer to the Diagnostic Trouble Code (DTC) Chart in «MULTIFUNCTION ELECTRONIC MODULE»(/mercury/mariner/ii-2011-2011/remont/communication-devices/#multifunction-electronic-module) article. No: Go to D2 .
  2. D2 RETRIEVE ALL PSCM DTCs Enter the following diagnostic mode on the scan tool: Self Test - PSCM . Are any DTCs present? Yes: For DTC C195C Go to D8 For all other DTCs Refer to the «POWER STEERING CONTROL MODULE (PSCM) DTC CHART»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-system__power-steering-control-module-pscm-dtc) in this service information. No: If the vehicle is currently exhibiting a lack of assist or inconsistent assist, Go to D3 . If the vehicle is not currently exhibiting a lack of assist or inconsistent assist, Go to D12 .
  3. D3 VERIFY PSCM ELECTRICAL CONNECTIONS Disconnect: PSCM C1436A. Disconnect: PSCM C1436B. Connect: PSCM C1436A. Connect: PSCM C1436B. NOTE: The connectors should make an audible "click" noise when seated correctly. Make sure both connectors are seated correctly, then test drive the vehicle and verify the concern. Is the concern still present? Yes: Go to D4 . No: The concern was caused by a loose or incorrectly connected electrical connector. RETURN the vehicle to the customer.
  4. D4 CALIBRATE THE STEERING WHEEL POSITION SENSOR Carry out steering wheel position sensor calibration. Refer to «STEERING WHEEL POSITION SENSOR CALIBRATION»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-system__steering-wheel-position-sensor-calibration) in this service information. Drive the vehicle and confirm that the condition is no longer present. Has the condition been corrected? Yes: The condition was due to an incomplete or incorrect sensor calibration. TEST the system for normal operation. No: Go to D5 .
  5. D5 CHECK THE SUSPENSION COMPONENTS Isolate the suspension components, check for any binding conditions. Are the suspension components free from any binding conditions? Yes: Go to D6 . No: ISOLATE the suspension component(s) that is causing the binding. INSTALL a new component(s) as necessary. Refer to «FRONT SUSPENSION»(/mercury/mariner/ii-2011-2011/remont/suspension-front/#front-suspension-system) article. TEST the system for normal operation.
  6. D6 CHECK THE STEERING GEAR AND LINKAGE Carry out the «Steering Linkage»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-system__steering-linkage) Component Test in this service information. Isolate the steering gear and linkage, check for any binding conditions. Are the steering gear and linkage free from any binding conditions? Yes: Go to D7 . No: ISOLATE the component(s) that is causing the binding. INSTALL a new component(s) as necessary. Refer to «POWER STEERING»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#power-steering-system) article or «STEERING LINKAGE»(/mercury/mariner/ii-2011-2011/remont/manual-power-steering/#steering-linkage) article. TEST the system for normal operation.
  7. D7 CHECK THE STEERING COLUMN SHAFT AND DASH SEAL Isolate the steering column shaft and dash seal, check for any binding conditions. Are the shaft and seal free from any binding conditions? Yes: Go to D8 . No: ISOLATE the component(s) that is causing the binding. INSTALL a new component(s) as necessary. Refer to Steering Column Shaft in «STEERING COLUMN»(/mercury/mariner/ii-2011-2011/remont/steering-column/#steering-column) article. TEST the system for normal operation.
  8. D8 CHECK THE CHARGING SYSTEM VOLTAGE WHILE LOADING THE EPAS SYSTEM Start the engine. Turn on all electrical accessories and allow the engine idle to stabilize. NOTE: A meter with a min/max feature and/or recording capabilities must be used to obtain accurate measurements. Connect the meter to the battery terminals; positive lead to positive terminal, negative lead to negative terminal. Set the meter to measure DC voltage. Set the meter range to greater than 15 volts. Enable the min/max or recording feature. NOTE: In order to provide adequate friction for a thorough test, make sure the vehicle is parked on an unsealed concrete or asphalt surface. While turning the steering wheel from stop to stop, measure the voltage between the battery positive post and the battery negative post. Record the lowest displayed voltage. Is the lowest displayed voltage greater than 12 volts? Yes: Go to D9 . No: Refer to «CHARGING SYSTEM»(/mercury/mariner/ii-2011-2011/remont/charging-system/#charging-system) article to diagnose the charging system.
  9. D9 CHECK THE IGNITION VOLTAGE TO THE PSCM Ignition OFF. Disconnect: PSCM C1463A. Ignition ON. Measure and record the voltage between the battery positive post and the battery negative post. Measure the voltage between PSCM C1463A-1, circuit CBP35 (YE/GY), harness side and ground. Is the voltage within 0.5 volt of the recorded battery voltage? Yes: Go to D10 . No: VERIFY SJB fuse 35 (10A) is OK. If OK, REPAIR circuit CBP35 (YE/GY). If the fuse is not OK, Refer to the «SYSTEM WIRING DIAGRAMS»(ref-395046) article to identify the possible causes of the circuit short. TEST the system for normal operation.
  10. D10 CHECK THE HIGH CURRENT CIRCUIT Ignition OFF. Connect: PSCM C1463A. Start the engine, turn on all electrical accessories and allow the engine idle to stabilize. NOTE: A meter with a min/max feature and/or recording capabilities must be used to obtain accurate measurements. NOTE: In order to obtain the best possible readings with the meter, make sure the meter leads have a good, clean connection to the item being measured. Connect the positive lead of the meter to PSCM C1463B-1 by backprobing the connector. Connect the negative lead of the meter to the battery negative post. Set the meter to measure DC voltage. Set the meter range to greater than 15 volts. Enable the min/max or recording feature. NOTE: In order to provide adequate friction for a thorough test, make sure the vehicle is parked on an unsealed concrete or asphalt surface. While turning the steering wheel from stop to stop, measure the voltage between PSCM C1463B-1, circuit SBB01 (RD), harness side and the battery negative post, by backprobing the PSCM connector. Record the lowest displayed voltage. Is the lowest displayed voltage within 0.5 volt of the lowest displayed voltage recorded in Step E8? Yes: Go to D11 . No: VERIFY BJB 80A MIDI fuse (WH) is OK. If OK, REPAIR circuit SBB01 (RD). If the fuse is not OK, Refer to the «SYSTEM WIRING DIAGRAMS»(ref-395046) article to identify the possible causes of the circuit short. TEST the system for normal operation.
  11. D11 CHECK THE PSCM GROUND CIRCUIT NOTE: In order to obtain the best possible readings with the meter, make sure the meter leads have a good, clean connection to the item being measured. With the engine still running and while turning the steering wheel from stop to stop, measure the voltage between PSCM C1463B-2, circuit GD116 (BK/VT), harness side and the battery negative post, by backprobing the PSCM connector. Is the voltage less than 0.5 volt? Yes: INSTALL a new steering column. Refer to «STEERING COLUMN»(/mercury/mariner/ii-2011-2011/remont/steering-column/#steering-column) article. No: REPAIR circuit GD116 (BK/VT). TEST the system for normal operation.
  12. D12 INSPECT THE EPAS ELECTRICAL CONNECTIONS Ignition OFF. Using a good light source, inspect the following connections for corrosion, pushed-out/bent pins, spread/bent terminals and loose connections: PSCM C1463A PSCM C1463B Ground G206 BJB 80A MIDI fuse (WH) SJB fuse 35 (10A) Using a suitable mating terminal, check each terminal for deformed or enlarged contacts by comparing the fit of the mating terminal between each pin location. Refer to «SYSTEM WIRING DIAGRAMS»(ref-395046) article, Connect or Repair Procedures for schematic and connector information. Are the connections OK? Yes: Go to D13 . No: REPAIR or INSTALL new as necessary. TEST the system for normal operation.
  13. D13 CHECK THE BATTERY VOLTAGE Connect all previously disconnected connectors. Start the engine. Turn on all electrical accessories and allow the engine idle to stabilize. NOTE: A meter with a min/max feature and/or recording capabilities must be used to obtain accurate measurements. Connect the meter to the battery terminals; positive lead to positive terminal, negative lead to negative terminal. Set the meter to measure DC voltage. Set the meter range to greater than 15 volts. Enable the min/max or recording feature. NOTE: In order to provide adequate friction for a thorough test, make sure the vehicle is parked on an unsealed concrete or asphalt surface. While turning the steering wheel quickly (at least 60 rpm or 1 revolution per second) from stop to stop, measure the voltage between the battery positive post and the battery negative post. Record the lowest displayed voltage. Is the lowest displayed voltage greater than 12 volts? Yes: Go to D14 . No: Refer to «CHARGING SYSTEM»(/mercury/mariner/ii-2011-2011/remont/charging-system/#charging-system) article to diagnose the charging system.
  14. D14 CHECK THE EPAS MOTOR VOLTAGE SUPPLY NOTE: A meter with a min/max feature and/or recording capabilities must be used to obtain accurate measurements. NOTE: In order to obtain the best possible readings with the meter, make sure the meter leads have a good, clean connection to the item being measured. Connect the positive lead of the meter to PSCM C1463B-1 by backprobing the connector. Connect the negative lead of the meter to the battery negative post. Set the meter to measure DC voltage. Set the meter range to greater than 15 volts. Enable the min/max or recording feature. NOTE: In order to provide adequate friction for a thorough test, make sure the vehicle is parked on an unsealed concrete or asphalt surface. With the engine still running and while turning the steering wheel quickly (at least 60 rpm or 1 revolution per second) from stop to stop, measure the voltage between PSCM C1463B-1, circuit SBB01 (RD), harness side and the battery negative post, by backprobing the PSCM connector. Record the lowest displayed voltage. Compare the recorded voltage to the voltage recorded in Step E12. Is voltage difference less than 0.5 volt? Yes: Go to D15 . No: VERIFY BJB 80A MIDI fuse (WH) is OK. If OK, REPAIR circuit SBB01 (RD). If the fuse is not OK, Refer to the «SYSTEM WIRING DIAGRAMS»(ref-395046) to identify the possible causes of the circuit short. TEST the system for normal operation.
  15. D15 CHECK THE GROUND CIRCUIT FOR EXCESSIVE RESISTANCE With the engine still running and while turning the steering wheel quickly (at least 60 rpm or 1 revolution per second) from stop to stop, measure the voltage between PSCM C1463B-2, circuit GD116 (BK/VT), harness side and the battery negative post, by backprobing the PSCM connector. Is the voltage less than 0.5 volt? Yes: The concern is not present at this time and may have been caused by a loose or corroded connector. CLEAR DTCs, RETURN the vehicle to the customer. No: REPAIR circuit GD116 (BK/VT). TEST the system for normal operation.

Steering Linkage

  1. With the vehicle in NEUTRAL, position it on a hoist. Refer to «JACKING & LIFTING»(/mercury/mariner/ii-2011-2011/remont/hoistjack/#jacking-lifting) article.
  2. Using hand force only, check the inner and outer tie rods for vertical and lateral movement in the tie-rod ball studs/sockets. If there is any lateral or vertical movement in the tie-rod ball studs/sockets (inner or outer), a new tie rod must be installed. Refer to the appropriate Steering System article for the procedure.

Steering Column Torsion Bar Test

  1. Put the steering wheel straight ahead and position the vehicle on a hoist.
  2. Raise the vehicle until the tires are several inches off the ground.
  3. Start the vehicle and slightly turn the wheel to the right and remove hands.
  4. If the steering wheel continues to turn on its own to the end stop, replace the steering column. Refer to «STEERING COLUMN»(/mercury/mariner/ii-2011-2011/remont/steering-column/#steering-column) article.

Steering Wheel Position Sensor Calibration

Pinpoint Test D

D6 PSCM

More articles — Steering