C195C

Steering System

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

Refer to Wiring Diagram Set 43, Power Steering Controls for schematic and connector information Electrical Diagrams.

Normal Operation

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 (Electronic Power Assist Steering) 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 (Electronic Power Assist Steering) system.

- DTC C195C (Electric Power Assist Limited Operation Mode Detected)- This DTC indicates that the voltage to the PSCM (Power Steering Control Module) 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:

- Battery and/or charging system voltage exceeds 16 volts.

- The charging system warning indicator is illuminated and battery/charging system voltage falls below 11.8 volts.

- 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 (Electronic Power Assist Steering) system is supplied to the PSCM (Power Steering Control Module) by Smart Junction Box (SJB) fuse 35 (10A) along circuit CBP35 (YE/GY). Fused battery voltage for the EPAS (Electronic Power Assist Steering) 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 (Power Steering Control Module) 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:

- Fuse(s)

- Wiring, terminals or connectors

- Vehicle battery/charging system

- Steering wheel position sensor calibration

- Steering components

- Suspension components

- Steering column

PINPOINT TEST D : POOR RETURNABILITY/STICKY STEERING, STEERING HAS A LACK OF ASSIST OR INCONSISTENT ASSIST AND DTC C195C

NOTICE: 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 Inspection and Verification.

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 Body Control Systems Body Control Systems.

No
GO to D2.

D2 RETRIEVE ALL PSCM (Power Steering Control Module) DTCs

- Enter the following diagnostic mode on the scan tool: Self Test- PSCM (Power Steering Control Module).

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 Steering.

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.

D3 VERIFY PSCM (Power Steering Control Module) ELECTRICAL CONNECTIONS

- Disconnect: PSCM (Power Steering Control Module) C2231A.

- Disconnect: PSCM (Power Steering Control Module) C2231B.

- Connect: PSCM (Power Steering Control Module) C2231A.

- Connect: PSCM (Power Steering Control Module) C2231B.

- 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.

D4 CALIBRATE THE STEERING WHEEL POSITION SENSOR

- Carry out steering wheel position sensor calibration. Refer to Steering Wheel Position Sensor Calibration .

- 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.

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. TEST the system for normal operation.

D6 CHECK THE STEERING GEAR AND LINKAGE

- Carry out the Steering Linkage Component Test Component Tests and General Diagnostics.

- 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. TEST the system for normal operation.

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. TEST the system for normal operation.

D8 CHECK THE CHARGING SYSTEM VOLTAGE WHILE LOADING THE EPAS (Electronic Power Assist Steering) 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.

- Measure the voltage between PSCM (Power Steering Control Module) C2231A-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 (Smart Junction Box) fuse 35 (10A) is OK. If OK, REPAIR circuit CBP35 (YE/GY).

If the fuse is not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams.

TEST the system for normal operation.

D10 CHECK THE HIGH CURRENT CIRCUIT

- Ignition OFF.

- Connect: PSCM (Power Steering Control Module) C2231A.

- 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 (Power Steering Control Module) C2231B-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 (Power Steering Control Module) C2231B-1, circuit SBB01 (RD), harness side and the battery negative post, by backprobing the PSCM (Power Steering Control Module) 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 (Battery Junction Box) 80A MIDI fuse (WH) is OK. If OK, REPAIR circuit SBB01 (RD).

If the fuse is not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams.

TEST the system for normal operation.

D11 CHECK THE PSCM (Power Steering Control Module) 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 (Power Steering Control Module) C2231B-2, circuit GD116 (BK/VT), harness side and the battery negative post, by backprobing the PSCM (Power Steering Control Module) connector.

Is the voltage less than 0.5 volt?

Yes
INSTALL a new steering column.

No
REPAIR circuit GD116 (BK/VT). TEST the system for normal operation.

D12 INSPECT THE EPAS (Electronic Power Assist Steering) 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 (Power Steering Control Module) C2231A

- PSCM (Power Steering Control Module) C2231B

- Ground G206

- BJB (Battery Junction Box) 80A MIDI fuse (WH)

- SJB (Smart Junction Box) 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 Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information Electrical Diagrams.

Are the connections OK?

Yes
GO to D13.

No
REPAIR or INSTALL new as necessary.

TEST the system for normal operation.

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 to diagnose the charging system.

D14 CHECK THE EPAS (Electronic Power Assist Steering) 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 (Power Steering Control Module) C2231B-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 (Power Steering Control Module) C2231B-1, circuit SBB01 (RD), harness side and the battery negative post, by backprobing the PSCM (Power Steering Control Module) 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 (Battery Junction Box) 80A MIDI fuse (WH) is OK. If OK, REPAIR circuit SBB01 (RD).

If the fuse is not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams.

TEST the system for normal operation.

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 (Power Steering Control Module) C2231B-2, circuit GD116 (BK/VT), harness side and the battery negative post, by backprobing the PSCM (Power Steering Control Module) 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.