Thermostat Map Cooling AGAIN!! - BimmerFest BMW Forum Fault code 2EF4 (B) — Map cooling thermostat mechanically stuck is stored in the DME. The engine does not overheat and the map thermostat operates properly. • Deterioration of coolant quality (the mixture concentration falls below 50%).
PROCEDURE CORRECTION CAUSE SITUATION MODEL
A. Electrical Active air flap fault code(s) (All models listed in this SIB) Correction A: This correction is to be used for all situations where the following fault codes are stored: B00 D 1. Replace the upper air flap actuator only, using the actuator suggested using ETK/AIR. Refer to attachment 1 “Upper air flap actuator. 279B (P0128), replaced thermostat: E46 Fanatics Forum Mahle's a decent supplier wrong coolant mix (too little coolant) can trip these MAP t-stats. Try unplugging, cleaning the connection, and replugging. Also test your coolant using a density tester to easily see if you have the right mix. Tap water (with electrolytes) can affect thermostat function as well. The language of machines is Logic.
BMW Fault Code Lookup - BMWFaultCodes situations where the following fault codes are stored: B00 1. Replace the upper air flap actuator only, using the actuator suggested using ETK/AIR. Refer to attachment 1 “Upper air flap actuator replacement instructions”. Copyright © BMW of North America, Inc.
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Recurring 279b code - E46 Fanatics Forum BMW Fault Code Lookup. Enter a BMW fault code (P or hex), complete the captcha, and click "Search" P-Codes will start with a P and are usually generated by generic scanners. Example: P Hex Codes are typically given by more advanced scanners. Examples: or 1B or 30FF.
Code 279B DME: Thermostat stuck: BimmerFest BMW Forum With the BMW Tools you can confirm the Load Signal, Intake Air Temp and the Radiator Outlet Temp sensor are not triggering the MAP thermostat. It looks like the positive voltage is always supplied to the thermostat, but the ECU provides the ground connection when needed to reduce coolant temp.
Error codes - BimmerFest BMW Forum Check your ambient temp sensor. A bit of a long shot, but if the DME takes it into consideration, then it may be a cause. Also check the coolant temp senor on the radiator outlet. I would record a coolant temperature log to see what the actual values are, from cold start idle for 5 minutes, then driving to your destination.
Code 2EF4 (279B) - now what? - They came back with code 2EF4 (B). According to the BMW bulletin from April , 6ers made between 09/04 and 12/04 have faulty engine harness and temp sensors and they need to be replaced. BMW is aware of that, obviously, but there was no recall and they pay for none of it.
