Pinpoint Test Z : U0140:00, U0422:68

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

Z1 VERIFY THE CUSTOMER CONCERN

Ignition ON.

Verify there is an observable symptom present.

Is an observable symptom present?

Yes

GO to Z2

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.

Z2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform the network test.
Does the BCM pass the network test?

Yes GO to Z3

No REFER to: Communications Network .

Z3 PERFORM THE RHVAC (REAR HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE SELF-TEST
- Using a diagnostic scan tool, perform the RHVAC control module self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes REFER to DTC Chart: RHVAC Control Module .

No GO to Z4

Z4 CHECK THE GWM (GATEWAY MODULE A) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, check the GWM Continuous Memory Diagnostic Trouble Codes (CMDTCs).
Are any Diagnostic Trouble Codes (DTCs) recorded?

Yes REFER to: Communications Network .

No GO to Z5

Z5 PERFORM THE BCM (BODY CONTROL MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the BCM self-test.
Are any non-network Diagnostic Trouble Codes (DTCs) present?

Yes REFER to DTC CHART: BODY CONTROL MODULE (BCM) .

No GO to Z6

Z6 RECHECK THE RHVAC (REAR HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE DIAGNOSTIC TROUBLE CODES (DTCS)

Using a diagnostic scan tool, clear the RHVAC control module Diagnostic Trouble Codes (DTCs).

Ignition OFF.

Ignition ON.

Wait 10 seconds.

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

Check the RHVAC control module Diagnostic Trouble Codes (DTCs).

Is DTC U0140:00 or DTC U0422:68 still present?

Yes

GO to Z7

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.

Z7 CHECK FOR OTHER CAUSES OF COMMUNICATION NETWORK CONCERN

NOTE: If new modules were installed prior to the DTC being set, the module configuration may 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 BCM or RHVAC control module. If recent service history is found:
- verify correct replacement module was installed
  - HVBOM 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

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

Is the observable symptom still present?

Yes

GO to Z8

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

Z8 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect the BCM and all related in-line 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 BCM and all related in-line 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, BCM guided routine is not applicable for this vehicle and market. Replace the component that was faulted through service information diagnosis.

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.