Initial Inspection and Diagnostic Overview
Inspection and VerificationCAUTION: Do not hold the steering wheel at the stops for an extended amount of time. Damage to the power steering pump can result.
NOTE: Make the following preliminary checks before repairing the steering system:
1. Verify the customer concern.
2. Visually inspect for obvious signs of mechanical damage.
Visual Inspection Chart
3. NOTE: The 3 areas that should be inspected for possible contamination are the power steering reservoir filter, flow control and pressure relief valve in the pump, and the check valve in the inlet port on the power steering gear (if equipped).
Inspect the power steering fluid for the following conditions:
^ Aerated or foamy: Purge the power steering system.
^ Overheating or contamination: Flush the power steering system.
4. Check the power steering system for fluid leaks.
^ Check the power steering fluid level.
NOTE: It may be necessary to add power steering fluid to achieve the correct level. With the ignition OFF:
^ Wipe off the power steering pump, power steering pressure hose, power steering return hose, power steering fluid cooler, hose assembly and steering gear.
^ CAUTION: Do not hold the steering wheel at the stops for an extended amount of time. Damage to the power steering pump can occur.
Start the engine and turn the steering wheel from stop-to-stop several times and check for leaks.
5. Inspect the power steering pressure and return hoses, fittings and O-rings for leaks.
^ If a leak is detected between a fitting nut, seal the fitting nut using a Teflon seal.
^ If a leak is detected at a fitting or clamp plate, tighten to specification. If leak is still evident, visually inspect the fittings, clamp plate, O-rings, and Teflon-seals. Install new as necessary.
^ If a leak is detected at the power steering reservoir, install a new reservoir.
^ If a leak is detected at a constant tension spring clamp, verify that the hose is fully installed on the fitting and that the hose clamp is correctly positioned. If the leak remains, install a new screw clamp.
^ If a leak is detected at a screw clamp joint, tighten the screw clamp. If the leak remains, inspect the tube end and install a new hose.
^ If a leak is detected at the power steering pump, install a new power steering pump.
NOTE: To inspect for leaks it may be necessary to remove the squeeze-type clamp from the steering gear boots.
6. Inspect the power steering gear for leaks. If a leak is detected at the power steering gear, install a new power steering gear.
7. If an obvious cause for an observed or reported concern is found, correct the cause before proceeding to the next step.
8. If the concern remains after the inspection, connect the diagnostic tool to the Data Link Connector (DLC) located beneath the instrument panel, and select the vehicle to be tested from the diagnostic tool menu. If the diagnostic tool does not communicate with the vehicle:
^ check that the program card is correctly installed.
^ check the connections to the vehicle.
^ check the ignition switch position.
9. If the diagnostic tool still does not communicate with the vehicle, refer to the tester manual.
10. Carry out the diagnostic tool data link test. If the diagnostic tool responds with:
^ SCP or ISO; all electronic control units no response/not equipped.
^ No response/not equipped for 4WAS module.
^ System passed, retrieve and record the continuous diagnostic trouble codes (DTC'S), erase the continuous DTC'S and carry out the self-test diagnostics for the 4 WAS module.
11. If the DTC'S retrieved are related to the concern, go to Air Suspension Module Diagnostic Trouble Code (DTC) Index to continue diagnostics.
12. If no DTC'S related to the concern are retrieved, GO to Symptom Chart continue diagnostics. Symptom Related Diagnostic Procedures