GENERAL PRECAUTIONS
| WARNING | To avoid injury from accidental air bag deployment, read and carefully follow all SERVICE PRECAUTIONS and also see DISABLING & ACTIVATING AIR BAG SYSTEM procedures in appropriate AIR BAG RESTRAINT SYSTEMS article in ACCESSORIES & EQUIPMENT. |
| CAUTION | When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. |
| CAUTION | Electronic components used in control systems are designed to carry very low voltages. Static electricity can cause a total or degrading failure in control modules or other electronic components containing integrated circuits. Before servicing electronic components, technician must ground himself and work area to discharge static electricity. |
SYSTEM PRECHECK
Check fluid for correct type, level and contamination. Check control modules, fluid flow solenoid actuator and wiring for damage or corrosion. Check power steering system for poor performance and leaks. Check speedometer operation to verify VSS signal.
VARIABLE EFFORT STEERING SYSTEM CHECK
Perform variable effort steering system check prior to testing system. (Scheme 15)and (Scheme 16). After each repair is performed, repeat system check to verify problem has been corrected. See EVO DIAGNOSTIC TROUBLE CODE DEFINITIONS.
Scheme 15
Scheme 16
| DTC | Fault Description |
|---|---|
| C0000 | Vehicle Speed Information Circuit Malfunction |
| C0472 | Steering Handwheel Sensor (HWSS) Circuit Low |
| C0473 | Steering Handwheel Sensor (HWSS) Circuit High |
| C0495 | EVO Tracking Error |
| C0498 | Steering Assist Control Solenoid Feed Circuit Low |
| C0499 | Steering Assist Control Solenoid Feed Circuit High |
| C0503 | Steering Assist Control Solenoid Return Circuit Low |
| C0504 | Steering Assist Control Solenoid Return Circuit High |
| C0559 | EEPROM Checksum Error |
EVO DIAGNOSTIC TROUBLE CODE DEFINITIONS
INTERMITTENTS
Faulty electrical connections and wiring cause most intermittent faults, although a damaged control module can occasionally be at fault. Also, power steering fluid flow actuator valve may be stuck and unable to calculate power steering assist.
Check for poor connections, a break in wire insulation exposing internal wire, or a wire that is broken inside insulation. Thoroughly inspect EVO/Passlock(R) module, VCM or PCM for backed-out terminals, broken locks, improperly formed or damaged terminals, weak terminal retaining tension, and proper wire routing.
STEERING WHEEL POSITION SENSOR
Note. Steering wheel position sensor is also referred to as "handwheel speed sensor" or "steering wheel rotation sensor".