The electro-hydraulic power steering (EHPS) scan tool data display values and
definition information that can assist in diagnosing EHPS related problems, especially
when no diagnostic trouble codes (DTC) are stored in memory. A vehicle's scan tool
data can be compared with the data display values from a known good vehicle in the
scan tool data display table. When data from the vehicle differs from the typical
data display value, the data definition information will help in understanding the
nature of the difference and the source of the problem. This list is in alphanumeric
order.
Data Definitions
Brake Pedal Travel -- -50 to 200 mm (-1.97 to 7.87 in): This data represents the chord length translation position of the
brake pedal through its normal range of movement.
BPP Sensor Rate -- 0 to +10%/25 ms: This data indicates
the rate of change of the brake pedal.
BPP Sensor Input Voltage -- 0 to 5 Volts: This data
represents the voltage being supplied to the BPP Sensor as measured by the EHPS system.
BPP Sensor Output Voltage -- 0 to 5 Volts: This
data represents a raw brake pedal position indicated by the voltage being received
by the EHPS module from the BPP Sensor as measured by the EHPS system.
EHPS 42 V Bus Voltage -- 0 to 76 Volts: This data indicates the voltage of the 42 V bus at the EHPS module.
EHPS Ignition 0-- OFF/ON: This data represents the
voltage of the Accessory signal at the EHPS module as read by the EHPS system.
EHPS Ignition 1 -- OFF/ON: This data represents
the voltage of the Ignition 1 signal at the EHPS module as read by the EHPS system.
EHPS Demand -- -100 to +100%: This data represents
the percentage of the available EHPS pump output being delivered as determined by
the EHPS system.
EHPS Demand Speed -- 0 to +7500 RPM: This data represents
the current pump speed being commanded as determined by the EHPS system.
EHPS ECU Temperature -- -180 to +180°C (-238 to +302°F): This data represents the temperature of the EHPS module in the EHPS
system as determined by the EHPS system.
EHPS Manifold Temperature -- -180 to +180°C (-238 to +302
°F): This data represents the temperature of the manifold in the
EHPS system as determined by the EHPS system.
EHPS Motor Current -- 0 to +200 A: This data represents
the current being used by the EHPS motor as measured by the EHPS system.
EHPS Motor RPM -- 0 to +7500 RPM: This data represents
the rotational speed of the EHPS motor as determined by the EHPS system.
Steering Wheel Rate -- 0 to 2048°/s: This data represents
the approximate degrees per second change of the steering wheel as determined by the
EHPS system.
Steering Wheel Sensor Phase A Volts -- Low/High: This data
represents the state of the Phase A digital output of the steering wheel sensor at
the EHPS unit as currently read by the EHPS system.
Steering Wheel Sensor Phase B Volts -- Low/High: This data represents the state of the Phase B digital output of the steering
wheel sensor at the EHPS unit as currently read by the EHPS system.
Vehicle Speed -- km/h (mph): This data represents the calculated
speed of the vehicle as determined by the PCM.