A/T - No Start/MIL ON/DTC P0706/Indicator Inaccurate
Bulletin No.: 04-07-30-029Date: June 30, 2004
TECHNICAL
Subject:
Service Engine Soon (SES) Light On, Diagnostic Trouble Code (DTC) P0706, Gear Range Indicator Incorrect/Inaccurate, No Start (Reprogram Powertrain Control Module (PCM))
Models:
2003 Chevrolet and GMC Light Duty Trucks
with 4L80-E Automatic Transmission (RPO MT1) or 4L85-E Automatic Transmission (RPO MN8)
Condition
Some customers may comment that the SES light is on. Some may comment that the vehicle will not start. Others may comment that the gear range indicator always reads "2" or "D2" regardless of the actual gear the transmission is in.
Cause
The original PCM diagnostic for DTC P0706 defaults the transmission position to Drive Range "2" when P0706 is set relating to the transmission range select circuit.
Correction
Follow the diagnostic tips and service procedure below to correct this condition.
Diagnostic Tips
^ When DTC P0706 sets, the vehicle will not start.
^ For additional information on DTC P0706, refer to SI Document.
^ Check for proper operation and adjustment of the Park Neutral Position (PNP) switch. Refer to Park/Neutral Position Switch Adjustment.
^ Check for proper operation and adjustment of the Range Selector Cable. Refer to Automatic Transmission Range Selector Cable Adjustment.
^ Check for proper electrical connections and terminal integrity.
^ Inspect ground G103.
^ Check to determine if the PCM calibration has been previously updated to a calibration to include the update for throttle body coking. If the PCM currently has this coking calibration, it is not necessary to reprogram the PCM again.
Repair Procedure
1. Diagnose and repair the cause of P0706.
2. Reprogram the PCM with TIS version 4, released in April 2004 or later titled "New calibration to reduce the potential for setting P0706. Also addresses 3-2 downshift feel."
With the new calibration, if the P0706 diagnostic fails, the software assumes Park if the engine is not running. If the engine is running, software uses PSM (pressure switch manifold) as back-up.
Use one of the tour following procedures to reprogram the PCM:
^ Service Programming System (SPS) Remote Procedure.
^ Service Programming System (SPS) Pass-Thru Procedure.
^ Service Programming System (SPS) Off Board Remote Procedure.
^ Service Programming System (SPS) Off Board Pass-Thru Procedure.
Warranty Information
For vehicles repaired under warranty, use the table.
For additional Labor Operation Information, refer to Warranty Administration Bulletin 02-06-04-057.
Disclaimer