Symptom Related Diagnostic Procedures

Symptom Troubleshooting Index








Find the symptom in the chart, and do the related procedures in the order listed until you find the cause.

Symptom Troubleshooting
Hard Steering
1. Check the power assist with vehicle parked.
Is the power assist more than 25 N (2.5 kgf, 5.5 lbs.)?
YES - Go to step 2.
NO - Power assist is OK.
2. Measure the power assist with the sensor inlet fitting and hose plugged.
Is the power assist more than 25 N (2.5 kgf, 5.5 lbs.)?
YES - Go to step 3.
NO - Go to step 8.
3. Measure steady-state fluid pressure from the pump at idle with T/N 07406-0010001 or with T/N 07406-001000A.
Is the pressure 1,500 kPa (15 kgf/cm2, 213 psi) or less?
YES - Go to step 4.
NO - Go to step 9.
4. Measure the pump relief pressure at idle with T/N 07406-0010001 or with T/N 07406001000A.
Is the pressure 7,600 - 8,300 kPa (78 - 85 kgf/cm2, 1,110 - 1,210 psi) or less?
YES - Go to step 5.
NO - Go to step 10.
5. With a spring scale, measure the power assist in both directions, to the left and to the right.
Are the 2 measurements within 5.0 N (0.51 kgf, 1.12 lbs.) of each other?
YES - Go to step 6.
NO - Go to step 11.
6. Measure the fluid pressure with both pressure gauge valves open (if so equipped), while turning the steering wheel fully to the left and fully to the right.
Is the pressure 7,600 - 8,300 kPa (78 - 85 kgf/cm2, 1,110 - 1,210 psi) or less?
YES - Go to step 7.
NO - Faulty gearbox.
7. Adjust the rack guide, and retest.
Is the steering OK?
YES - Repair is completed.
NO - Faulty gearboxes
8. Check for fluid leaks at the hoses, lines, joints and connections.
Are the hoses, lines, joints and connections OK?
YES - Faulty power steering speed sensor or valve body unites
NO - Repair or replace the lines or hoses.
9. Check the supply and return lines between the pump and the gearbox for clogging and deformation.
Are the lines clogged or deformed?
YES - Repair or replace the lines.
NO - Faulty valve body unit.
10. Check the flow control valve for smooth movement and leaks.
Is the flow control valve OK?
YES - Faulty pump assembly.
NO - Faulty flow control valve.
11. Check the cylinder lines A and B for deformation.
Are the A or B lines deformed?
YES - Replace the lines.
NO - Go to step 12.
12. Check for a bent rack shaft or misadjusted rack guide (too tight).
Is the rack shaft bent or the rack guide adjusted too tight?
YES - Replace the rack shaft or readjust the rack guide.
NO - Faulty valve body unit.