A4 - A6

A4 Test Drive Vehicle
- Ensure VAPS system is connected.
- Drive vehicle up to 55 mph and set speed control.
- While driving vehicle, note operation of speedometer (used in step A5).
Do steering efforts change and is effort balanced (left vs. right turn direction)?
Yes to both.
Diagnostics complete.
System is OK.
No change in steering effort (always too hard or always too easy).
Go to A5.
Efforts unbalanced left to right.
REPLACE steering gear assembly. Service and Repair
REPEAT A4.

A5 Speedometer Check
- The VAPS system requires a speed signal from the vehicle speed sensor.
- Note operation of speedometer and speed control (from Step A4).
If the speedometer or speed control does not work, these systems should be serviced using the appropriate diagnostic and service procedures.
Are speedometer and speed control operating properly?
Yes
Go to A6.
No
SERVICE as required.
Go to A4.

A6 Speed Sensor Circuit Check
- Disconnect VAPS connector from module.






- Connect DVOM across Circuits 150 and 563.
- Measure resistance.
Is the resistance is between 150-225 Ohms
Yes
Go to A7. A7 - A8
Is the resistance is less than 150 or greater than 225 Ohms
Yes
SERVICE harness.
Go to A4.