Pinpoint Test A: Steering Has Lack Of Assist Or Inconsistent Assist

Steering System







Pinpoint Tests

Pinpoint Test A: Steering Has Lack of Assist or Inconsistent Assist

NOTE: Hard steering or lack of assist is experienced when the steering wheel effort is higher than normal. Hard steering can remain constant through the full turn, occur near the end of a turn or differ right to left.

This pinpoint test is intended to diagnose the following:
- Power steering fluid contamination
- Steering gear
- Power steering pump
- Power steering hoses



PINPOINT TEST A: STEERING HAS LACK OF ASSIST OR INCONSISTENT ASSIST

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A1 CHECK FOR POWER STEERING FLUID CONTAMINATION


- Check the power steering fluid for contamination.
- Is the power steering fluid contaminated?

Yes
FLUSH the power steering system. REFER to Power Steering System Flushing Power Steering System Flushing. CHECK the system for normal operation. If assist concern still exists, GO to A2.

No
GO to A2.

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A2 CHECK THE STEERING ASSIST WITH THE ENGINE RPM RAISED


- NOTICE: Do not hold the steering wheel at the stops for an extended amount of time. Damage to the power steering pump may occur.
- Set the engine at 2,100 rpm and turn the steering wheel fully to the left and right.
- Is steering assist fully restored to normal with the engine rpm raised?

Yes
INSTALL a new power steering pump.

No
GO to A3.

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A3 CHECK FOR A CHANGE OF ASSIST ON LEFT AND RIGHT TURNS


- With the engine at idle, turn the steering wheel fully to the left and to the right.
- Does the steering assist change when turning from right to left?

Yes
INSTALL a new steering gear.

No
GO to A4.

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A4 CHECK THE STEERING LINES AND HOSES FOR RESTRICTIONS


- Inspect the steering lines and hoses for damage, kinks or restrictions.
- Are the steering lines or hoses damaged, kinked or restricted?

Yes
INSTALL new lines or hoses as necessary.

No
GO to A5.

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A5 MONITOR THE ENGINE RPM CHANGES


NOTICE: Do not hold the steering wheel at the stops for an extended amount of time. Damage to the power steering pump may occur.

NOTE: Make sure that the vehicle is on a flat dry surface, all accessories are in the OFF position and that the steering system is at normal operating temperature.

- Connect the scan tool.
- Start the engine.
- With the engine at idle, raise the power steering fluid temperature to 74-80°C (165-176°F) by rotating the steering wheel fully to the left and right several times.
- While monitoring the Engine Revolutions Per Minute (RPM) PID with the scan tool, turn the steering wheel quickly to the left stop position and then to the right stop position.
- Note the engine rpm during the turns.
- Does the engine rpm change (even temporarily) more than 30 rpm when turning the steering wheel?

Yes
INSTALL a new steering gear.

No
INSTALL a new power steering pump.

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