C220D

C220D-00-ELECTRICAL POWERED HYDRAULIC STEERING MODULE INTERNAL

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Electro-Hydraulic Power Steering (EHPS) Pump assembly contains a control module, brushless electric motor, and hydraulic pump integrated into a single unit. The EHPS Pump draws power from the 12-Volt electrical system and provides the necessary flow and pressure to the steering gear to provide normal power steering. The EHPS Pump requires communication over the CAN C bus to function properly. The output flow of the EHPS Pump is varied as a function of Steering Wheel Rate (received from SAS) and Vehicle Speed (received from ABS Module) in order to provide the optimum flow of power steering fluid to the steering gear under all operating conditions. The EHPS Pump will start to provide steering assist when the Vehicle speed message greater than 5 km/h (3 mph) is received on CAN C. If the Vehicle Speed message is missing at vehicle startup, the EHPS Pump will not operate. If the Vehicle Speed message is lost during operation the EHPS pump will use a default vehicle speed of 85 km/h (59 mph) to calculate desired flow and as a result, steering effort will no longer be speed sensitive. If the Steering Wheel Position message is lost the EHPS Pump will use a default steering wheel rate of 230°/sec to calculate desired flow and as a result, steering effort may be higher on evasive steering maneuvers. The EHPS pump will resume normal operation automatically once any missing message or out of range condition noted above is restored to normal.

- When Monitored:
Continuously.

- Set Condition:
If the Electro-Hydraulic Power Steering (EHPS) Module detects an internal fault, this DTC will set. Most of internal faults that can set this DTC will result in the EPS Pump not operating for the remainder of the current key cycle.





ACTIVE DTC

NOTE: This DTC must be active for the results of this test to be valid.

1. Ignition on, engine not running.
2. With the scan tool, record and erase DTCs.
3. Start the engine and run for two minutes.
4. With the scan tool, read DTCs.

Does the scan tool display: C220D-00-ELECTRICAL POWERED HYDRAULIC STEERING MODULE INTERNAL?

Yes

- Replace the Electronic Power Steering (EHPS) Pump. Power Steering Pump - Removal.
- Perform the EHPS Verification Test. EHPS Verification Test.

No

- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring harness and electrical connectors.
- Perform the EHPS Verification Test. EHPS Verification Test.