Pinpoint Test Cm: PSCM (Power Steering Control Module) DTC (Diagnostic Trouble Code) U0557:00 Invalid Data Received From Front Controls Interface Module "A"
NOTE:
The FCIM may also be known as the HVAC module.
Refer to POWER STEERING CONTROLS Wiring Diagrams for schematic and connector information.
Normal Operation and Fault Conditions
REFER to: Power Steering - System Operation and Component Description .
- Description
- The PSCM monitors the HS-CAN when the voltage to the PSCM is greater than 10 volts and there are no Diagnostic Trouble Codes (DTCs) present inhibiting PSCM operation.
- Pinpoint Test Applicability
- This test applies to PSCMDTC U0557 Invalid Data Received from the FCIM only. It does not apply to any other module except the PSCM.
- DTC Diagnostic Strategy
- If the module DTC list results in a large number of Diagnostic Trouble Codes (DTCs), diagnose all module hard faults first (C102D, C1B00, C200B, C200C, C200D, U2011 and U3000) before diagnosing any network faults (lost communication or invalid data). If voltage concern Diagnostic Trouble Codes (DTCs) are present, diagnose those after any module hard faults and before any network faults. Diagnose all current and active Diagnostic Trouble Codes (DTCs) before diagnosing any historic Diagnostic Trouble Codes (DTCs).
- Pinpoint Test Purpose
- To direct the diagnosis to the module and associated circuit sending the faulty or unknown information in the messages.
- Diagnostic Aids
- For additional information on the messages sent to the PSCM from the FCIM module, refer to the Network Message Chart .
- DTC U0557:00 indicates a concern with the lane information sent from the FCIM. The module reporting this DTC is not the problem module. Do not install a new PSCM as part of the repair for PSCMDTC U0557:00.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Condition |
|---|---|---|
| PSCM U0557:00 | Invalid Data Received From Front Controls Interface Module "A": No Sub Type Information | This DTC is set if the PSCM receives an "fault" or "unknown" message from the FCIM instead of valid information. |
Possible Sources
- HS-CAN concern
- FCIM
- This DTC sets when the PSCM does not receive the FCIM messages within a certain time frame. This can occur if the FCIM wiring harness or electrical connectors are loose or damaged, or if the vehicle battery state of charge levels are low. Consult the DTC Index for additional information if needed.
Pinpoint Tests CM: PSCM DTC U0557 Invalid Data Received From Front Controls Interface Module "A"