Also check these locations for chaffed wires these are known trouble spots, and can lead to the damage of control modules...
Page 1 of 3 No Communication with Any Modules, Memory Seat May Not Recall, Multiple U-DTCs ...
No Communication with Any Modules, Memory Seat May Not Recall, Multiple U-DTCs Set or Instrument Panel Cluster (IPC) Warning Indicators, Crank No Start (Inspect/Repair Affected Wiring Harness) TECHNICAL SERVICE BULLETIN Reference Number(s): 03-08-50-014A, Date of Issue: January 20, 2006 2003-2006 Cadillac Escalade, Escalade ESV, Escalade EXT; 2003-2006 Chevrolet Avalanche, Silverado, Suburban, Tahoe; 2003-2006 GMC Sierra, Yukon, Yukon XL; with Front, Individual (Non-Bkt) Seat (RPO AN3) and/or Active Brake Control (Stabilitrak(R)) (RPO JL4) This bulletin is being revised to update the various conditions and add the 2004-2006 model years, additional diagnostic and warranty information. Please discard Corporate Bulletin Number 03-08-50-014 (Section 08 - Body & Accessories). Related Ref Number(s): 03-08-50-014A Affected Model(s): Supercedes:
Some customers may comment on any of the following conditions:
Various IPC Warning indicators are coming on. " Driver Information Center (DIC) displays "Unknown Driver". " Memory seat may not recall. " RKE fobs may be inoperative. " Radio or HVAC may shut off. " Engine cranks but will not start. "
Upon investigation, the Technician may find multiple U-DTCs set.
Page 2 of 3 No Communication with Any Modules, Memory Seat May Not Recall, Multiple U-DTCs ...
Fig. 1: Possible Pinch/Chafe Location Courtesy of GENERAL MOTORS CORP.
On RPO AN3 equipped vehicles, a chafed or pinched seat wiring harness under the driver seat may be a cause of this condition. Because of the routing, a portion of the seat wiring harness may rest on the inboard edge of the seat track or frame. Over time, the harness may be pinched or chafed because of the seat movement. Refer to the above illustration. The illustration shows the inverted position of the seat bottom. The arrow shows the primary location of the possible harness chafing/pinching.
Also, on any of the above listed vehicles, the PCM wiring harness may be chafing against the precharge pump bracket (Refer to Document ID# 1252958) or the battery tray.
On RPO AN3 vehicles, inspect the routing of the seat wiring harness. Reroute the seat wiring harness and attaching harness fastener (1) to the opposite side of the seat module bracket. Repair the harness as necessary. Refer to Wiring Repairs in the Wiring Systems sub-section of SI. The seat may have to be removed for ease of access and proper repair of the wiring harness.
Inspect the routing of the PCM wiring harness at the precharge pump bracket and the battery tray. Repair the harness as necessary. Refer to Wiring Repairs in the Wiring Systems sub-section of SI.
Page 3 of 3 No Communication with Any Modules, Memory Seat May Not Recall, Multiple U-DTCs ...
If any of the above conditions still remain after this repair, refer to SI for further diagnostic information.
For vehicles repaired under warranty, use:
Labor OperationDescriptionLabor Time N9542 Wiring and/or Connector - Seat System and/or PCM - Repair 0.2-0.4 hr
Wednesday, October 6th, 2010 AT 11:06 PM