Friday, December 27, 2019

2010 Cadillac Truck Escalade AWD V8-6.2L Page 2974

* The vehicle power mode master requires serial data communication to occur for this specific module.

Conditions for Setting the DTC

A supervised periodic message that includes the transmitter module availability has not been received.

Action Taken When the DTC Sets

The modules is never signaled, therefore the specific subsystems will not function.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.

* A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.

Circuit/System Verification

With a scan tool, ensure the following DTCs are not present in the modules as follows:

HPCM

U189A

SDGM

* U182A

* U0074

If any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic

Trouble Code (DTC) List - Vehicle) to diagnose that DTC.

U1818

DTC U1818

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptor

DTC U1818 00

- Lost Communication With ECM/PCM A on Bus B

Diagnostic Fault Information

Circuit/System Description

Modules connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and

commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the

serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an

availability indication of the transmitter module. Each message contains the identification number of the transmitter module.

DTC U1818 will set in the serial data gateway module (SDGM) when no communication is established with the ECM on the PTLAN serial data