Steering System And 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
. 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 diagnostic approach to pinpoint the responsible system. If this is not the causal system for the symptom, refer back to NOISE, VIBRATION & HARSHNESS
for the next likely system and continue diagnostics.
Select a symptom to see recommended actions
Message center displays STEERING MALFUNCTION SERVICE NOW
| Possible Source | Action |
|---|---|
|
GO to PINPOINT TEST KC |
Message center displays STEERING ASSIST MALFUNCTION SERVICE REQUIRED
| Possible Source | Action |
|---|---|
|
GO to PINPOINT TEST KC |
Message center displays STEERING LOSS STOP SAFELY
| Possible Source | Action |
|---|---|
|
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
- Loose, damaged or worn inner or outer tie rods
- 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.
- If equipped, active park assist can only be activated if the steering system is providing full steering assist. If the active park assist system is currently in use and the steering system experiences a partial or non-assist event, active park assist is deactivated.
Possible Source Action - Fuse(s)
- Wiring, terminals or connectors
- Suspension components
- Steering gear internal failure
- Loose, damaged or worn inner or outer tie rods
GO to PINPOINT TEST I
No communication with the PSCM
| Possible Source | Action |
|---|---|
|
|
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 steering correction is completed.
Possible Source Action - Binding lower steering column shaft coupling/U-joint
- Loose, damaged or worn inner or outer tie rods
- Binding suspension components
- Binding steering gear
- Binding steering gear bearing(s)
- Binding steering column shaft dash panel seal
- Alignment/suspension
- GO to PINPOINT TEST I
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 |
|---|---|
|
|
|
|
|
GO to PINPOINT TEST J |
|
GO to PINPOINT TEST K |
|
|
Grinding noise or gravely feel
| Possible Source | Action |
|---|---|
|
GO to PINPOINT TEST K |
Shimmy
| Possible Source | Action |
|---|---|
|
GO to PINPOINT TEST J |
Steering column squeaks, clicks or grinds
| Possible Source | Action |
|---|---|
|
|
|
|
Steering Wheel is Off Center
| Possible Source | Action |
|---|---|
|
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 in STEERING COLUMN .
- Steering gear
- COMPARE to other EPAS equipped vehicles. If the noise is excessive, INSTALL a new EPAS gear.
- REFER to Steering Gear .