Pinpoint Test Ab: U0131:00, U0131:87 Or U0420:00

Normal Operation and Fault Conditions

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
IPMB U0131:00	Lost Communication With Power Steering Control Module "A": No Sub Type Information	Sets in continuous memory in the IPMB if data messages received from the PSCM are missing for 5 seconds or longer.
IPMB U0131:87	Lost Communication With Power Steering Control Module "A": Missing Message	Sets in continuous memory in the IPMB if it is missing a message from the PSCM for 5 seconds or longer.
IPMB U0420:00	Invalid Data Received from Power Steering Control Module "A": No Sub Type Information	Sets in the IPMB when the IPMB received invalid network data from the PSCM through the GWM for 5 seconds or longer.

Possible Sources

Communication concern
PSCM
IPMB

AB1 VERIFY THE CUSTOMER CONCERN

Verify there is an observable symptom present.

Is an observable symptom present?

Yes

GO to AB2

No	Clear the DTC. The system is operating normally at this time. The DTC may have been set due to high network traffic, or an intermittent fault condition.

AB2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform the network test.
Does the PSCM pass the network test?

Yes GO to AB3

No REFER to: Communications Network .

AB3 PERFORM THE IPMB (IMAGE PROCESSING MODULE B) CONTROL MODULE SELF-TEST
- Using a diagnostic scan tool, perform the IPMB module self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes REFER to Diagnostic Trouble Code (DTC) Chart .

No GO to AB4

AB4 PERFORM THE PSCM (POWER STEERING CONTROL MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the PSCM self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes REFER to: Power Steering .

No GO to AB5

AB5 RECHECK THE IPMB (IMAGE PROCESSING MODULE B) DIAGNOSTIC TROUBLE CODES (DTCS)

Using a diagnostic scan tool, clear the IPMB Diagnostic Trouble Codes (DTCs).

Ignition OFF.

Ignition ON.

Wait 10 seconds.

Using a diagnostic scan tool, perform the IPMB continuous memory self-test.

Check the IPMB Diagnostic Trouble Codes (CMDTCs).

Is DTC U0131:00, U0131:87 or U0420:00 present?

Yes

GO to AB6

No	The system is operating correctly at this time. The DTC may have been set due to high network traffic, or an intermittent fault condition.

AB6 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN

NOTE: If new modules were installed prior to the DTC being set, the module configuration can be incorrectly set during the PMI, or the PMI may not have been carried out.

CHECK the vehicle service history for recent service actions related to the PSCM or IPMB. If recent service history is found:
- verify correct replacement module was installed
  - vehicle parts build may be used to verify correct part fitment
- verify the configuration of replacement module was correct
  - re-configure module using as-built data if prior configuration is suspect
- verify the module was not obtained from a like vehicle and installed into customer vehicle
  - return the swapped module to source vehicle and obtain new replacement module
  - if a new replacement module is installed, PERFORM PMI using as-built data

Operate the system and determine if the observable symptom is still present.

Is the observable symptom still present?

Yes

GO to AB7

No	The system is operating correctly at this time. The concern may have been due to incorrect parts replacement procedures or incorrect module configuration.

AB7 CHECK FOR CORRECT PSCM (POWER STEERING CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all PSCM connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the PSCM connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, REFER to: Steering Wheel and Column Electrical Components .

No	The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.