Pinpoint Test P: U0140:00, U0422:68, U0422:81

Refer to Wiring Diagrams AUTOMATIC CLIMATE CONTROL SYSTEM for schematic and connector information.

Normal Operation and Fault Conditions

With the ignition ON, the BCM sends messages to the HVAC control module over the MS-CAN. If the HVAC control module does not receive these messages within the specified time frame, the module sets a DTC. This can be due to a BCM failure, a circuit failure on the MS-CAN or an excessive load on the network. For information on the messages sent to the HVAC control module by the BCM, REFER to: Climate Control System - Vehicles With: Electronic Manual Temperature Control (EMTC) - System Operation and Component Description .

Inspect for loose or corroded BCM and HVAC control module connections.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
HVAC U0140:00	Lost Communication With Body Control Module: No Sub Type Information	If data messages received from the BCM over the MS-CAN are missing for 5 seconds or more.
HVAC U0422:68	Invalid Data Received From Body Control Module: Event Information	A fault in the BCM or data messages missing for 5 seconds or more.
HVAC U0422:81	Invalid Data Received From Body Control Module: Invalid Serial Data Received	A fault in the BCM.

Possible Sources

Network communication concern
Wiring, terminals or connectors
Over or undervoltage concerns
BCM
HVAC control module

P1 VERIFY THE CUSTOMER CONCERN

Ignition ON.

Verify there is an observable symptom present.

Is an observable symptom present?

Yes

GO to P2

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.

P2 CHECK THE COMMUNICATION NETWORK
- Using a diagnostic scan tool, perform a network test.
Does the BCM pass the network test?

Yes GO to P3

No REFER to: Communications Network .

P3 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE BCM (BODY CONTROL MODULE) SELF-TEST
- Using a diagnostic scan tool, perform the BCM self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?

Yes REFER to: Body Control Module (BCM) .

No GO to P4

P4 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE (HVAC) HEATING, VENTILATION AND AIR CONDITIONING CONTROL MODULE SELF-TEST
- Using a diagnostic scan tool, perform the HVAC control module self-test.
Is DTC U3003:16 or DTC U3003:17 recorded?

Yes GO to Pinpoint Test R

No GO to P5

P5 RECHECK THE (HVAC) HEATING, VENTILATION AND AIR CONDITIONING CONTROL MODULE DIAGNOSTIC TROUBLE CODES (DTCS)

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.

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

Ignition OFF.

Ignition ON.

Wait 10 seconds.

Using a diagnostic scan tool, perform the HVAC control module self-test.

Is DTC U0140:00 still present?

Yes

GO to P6

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

P6 CHECK FOR DTC (DIAGNOSTIC TROUBLE CODE) U0140:00, U0422:68 OR U0422:81 SET IN OTHER MODULES

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

Ignition OFF.

Ignition ON.

Wait 10 seconds.

Using a diagnostic scan tool, retrieve all continuous memory Diagnostic Trouble Codes (DTCs).

Is DTC U0140:00, U0422:68 or U0422:81 set in other modules on the network?

Yes	REFER to: Communications Network . REFER to the BCM does not communicate with the diagnostic scan tool to DIAGNOSE the CAN circuits.

GO to P7

P7 CHECK FOR CORRECT HVAC (HEATING, VENTILATION AND AIR CONDITIONING) CONTROL MODULE OPERATION

Ignition OFF.

Disconnect and inspect all HVAC control module electrical connectors (if not previously disconnected).

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

Connect all HVAC control module electrical 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, INSTALL a new HVAC control module. REFER to the appropriate REMOVAL AND INSTALLATION .

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