NUMBER: 18-041-18 REV. B
GROUP: 18 - Vehicle Performance
DATE: October 16, 2018
SUBJECT: Flash: Powertrain Control Module (PCM) Updates
OVERVIEW: This bulletin involves reprogramming the PCM with the latest available software.
MODELS: 2018 (JL) Jeep Wrangler
NOTE: This bulletin applies to vehicles within the following markets/countries: NAFTA, EMEA, LATAM and APAC.
NOTE: This bulletin applies to vehicles built on or after **September 11, 2017 (MDH 0911XX) and on or before September 26, 2018 (MDH 0926XX)** equipped with a 3.6L V6 24V VVT Engine Up Grade I W/ESS (Sales Code ERC).
NOTE: The RRT portion of this bulletin applies to vehicles built on or before February 27, 2018 (MDH 0227XX) equipped with a 3.6L V6 24V VVT Engine Up Grade I W/ESS (Sales Code ERC).
Customers may experience one or more of the following:
• **Excessive blower fan noise when the A/C is on MAX output.
• Intermittent rough idle or idle surging, when coming to a stop (Automatic transmission equipped vehicles only).
• Random Electronic Stability Control (ESC) lamp illuminates in the Instrument Panel Cluster (IPC).**
• Driving at vehicle speeds while in first gear and shifting into neutral, a message 9Shift to 1st gear not allowed9 message appears in the Electronic Vehicle Information Center (EVIC) when conditions are not met (Manual transmission equipped vehicles only).
• 3 km (2 mph) difference between cruise set speed versus actual display speed.
• During cold vehicle operation and the use of cruise control on vehicles equipped with an automatic transmission, the engine RPMs may drop below idle speed while cruise control is engaged, this may occur if the customer presses the accelerator pedal to achieve a vehicle speed greater than the cruise control speed and then releasing it.
• Radio or IPC may reboot (flash off/flash on) during an Engine Stop Start (ESS) shutdown in cold conditions with a battery temperature below 12° C (10°F).
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idles rough 2018 Jeep Wrangler JL
2018 Jeep Wrangler JL fan sounds like a jet engine