Steering System and NVH

Message center displays STEERING MALFUNCTION SERVICE NOW

Possible Source	Action
DTCs present in the PSCM	GO to PINPOINT TEST KC

Message center displays STEERING ASSIST MALFUNCTION SERVICE REQUIRED

Possible Source	Action
DTCs present in the PSCM	GO to PINPOINT TEST KC

Message center displays STEERING LOSS STOP SAFELY

Possible Source	Action
DTCs present in the PSCM	GO to PINPOINT TEST KC

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.

Possible Source	Action
Steering column shaft/U-joints Steering linkage Steering gear internal failure.	GO to PINPOINT TEST G

Lack of assist or inconsistent assist

• NOTE: If the steering wheel is held at the end of travel for more than 2 seconds, the PSCM noticeably reduces assist to the EPAS gear. This is a normal condition programmed into the PSCM to protect the system from permanent damage.
• NOTE: There are multiple conditions (overheating protection, high voltage, low voltage, etc.) which result in limited or reduced assist from the EPAS system. Address all existing PSCM DTCs prior to diagnosing any assist symptoms.
• 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/lack of assist and poor returnability/sticky steering.

Possible Source	Action
Fuse(s) Wiring, terminals or connectors Suspension components Steering gear internal failure Inner tie rods Outer tie rods	GO to PINPOINT TEST X

No communication with the PSCM

Possible Source	Action
Fuse(s) Wiring, terminals or connectors. High-speed communication area network (HS-CAN) bus Steering gear	REFER to MODULE COMMUNICATIONS NETWORK to diagnose the no communication concern.

Poor returnability/sticky steering

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

Possible Source	Action
Fuses Electrical connectors Under inflated or mismatched tires Misaligned steering column shrouds Binding lower steering column shaft coupling/U-joint. Loose, worn or damaged steering linkage. Binding suspension components. Binding steering gear. Binding steering gear bearing(s). Binding steering column shaft dash panel seal.	GO to PINPOINT TEST X

Steering system pull/drift/wander

• NOTE: The EPAS system is designed to compensate for some steering issues (drift, pull, wander, etc.).
• Drift describes what a vehicle with this condition does with the hands off the steering wheel
• Pull is described as a tugging sensation on the steering wheel felt by the driver, which must be overcome to keep the vehicle going straight
• 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
• A vehicle-related drift or 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. Drift or pull can be induced by conditions external to the vehicle, such as wind or road camber

Possible Source	Action
Alignment Tire(s) Suspension Steering column shaft/U-joints Steering column Steering gear mounts Steering Gear	GO to PINPOINT TEST H

Feedback (rattle, chuckle or knocking noise) - roughness is felt in the steering wheel when driven over rough surfaces

Possible Source	Action
Steering column shaft/coupling bolts are loose.	TIGHTEN the bolts to specification. REFER to STEERING COLUMN .
Steering column shaft/coupling joints damaged or worn.	INSTALL a new steering column shaft. REFER to STEERING COLUMN .
Loose, damaged or worn tie-rod ends	GO to PINPOINT TEST J
Damaged steering gear bellows boots	GO to PINPOINT TEST K
Steering gear insulators or mounting bolts loose or damaged	TIGHTEN the bolts to specification or INSTALL new bolts as necessary. REFER to Steering Gear . If the steering gear insulators are damaged or missing, INSTALL a new EPAS gear. REFER to Steering Gear .

Grinding noise or gravely feel

Possible Source	Action
Damaged steering gear bellows boots	GO to PINPOINT TEST K

Shimmy

Possible Source	Action
Loose, damaged or worn tie-rod ends	GO to PINPOINT TEST J

Steering column squeaks, clicks or grinds

Possible Source	Action
Loose or misaligned steering column shrouds.	TIGHTEN the steering column shroud screws.
Steering wheel rubbing against steering column shrouds.	ALIGN the steering column shrouds.

Steering gear clunk occurs only while cornering over a bump (can be temperature sensitive)

• NOTE: Some noise when turning into the steering stops is normal.

Possible Source	Action
Steering gear insulators or mounting bolts loose or damaged	If the mounting bolts are loose, INSTALL new bolts and TIGHTEN to specification. REFER to Steering Gear . If the steering gear insulators are damaged or missing, INSTALL a new EPAS gear. REFER to Steering Gear .
Steering gear has reached the end of travel and is contacting the steering stops.	COMPARE to other EPAS vehicles. If the noise is excessive, INSPECT the outer tie-rods and suspension ball joints. TIGHTEN or INSTALL new as necessary.

Steering Wheel is Off Center

Possible Source	Action
Alignment Steering gear	GO to PINPOINT TEST H

Whirring or whine noise that gets louder with increased steering wheel speed

• NOTE: Some amount of noise from the EPAS gear is considered normal.

Possible Source	Action
Grounded or loose steering column shaft dash panel seal.	REPAIR or INSTALL a new dash panel seal as necessary. REFER to STEERING COLUMN SHAFT .
Steering gear	COMPARE to other EPAS equipped vehicles. If the noise is excessive, INSTALL a new EPAS gear. REFER to Steering Gear .