02 ML55 AMG LIMP MODE IN THE COLD
04-12-2019, 11:51 PM
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02 ML55 AMG LIMP MODE IN THE COLD
It's throwing P0720 & P0500. It's not the conductor plate, wheel sensors, fluid level or anything obvious. Vehicle goes into limp mode immediately (at start up) when ambient temperature is roughly 60F or below.
I have determined that engine compartment temperature is what matters. I've implemented an unorthodox test when car was stone cold, with ambient temp between 55F to 60F. I used a bullet kerosene heater, aimed at the engine compartment for 15 min or so. Got in the car and problem was gone.
This isolates the thermal increase to the engine compartment, as I am sure the internal temps of engine and or trans would remain at ambient temps, in-spite of increased engine compartment temps. No operating temperatures would occur without engine being fired up.
Without the Kerosene heater test, the same resolve of said issue will occur naturally and somewhat quickly in 60F temps and above (even before reaching operating temp) and diapering entirely in summer weather. However, in colder weather (say 40F to 30F) said issue will resolve, only after a prolonged period; until totally reaching operating temp.
When I say (limp mode) I mean that the car throws dash lights: BAS/ESP, ETS, ABS and vehicle will not shift out of first gear. - Put that one in your pipe and smoke it. Please let me know what you come up with.
I have determined that engine compartment temperature is what matters. I've implemented an unorthodox test when car was stone cold, with ambient temp between 55F to 60F. I used a bullet kerosene heater, aimed at the engine compartment for 15 min or so. Got in the car and problem was gone.
This isolates the thermal increase to the engine compartment, as I am sure the internal temps of engine and or trans would remain at ambient temps, in-spite of increased engine compartment temps. No operating temperatures would occur without engine being fired up.
Without the Kerosene heater test, the same resolve of said issue will occur naturally and somewhat quickly in 60F temps and above (even before reaching operating temp) and diapering entirely in summer weather. However, in colder weather (say 40F to 30F) said issue will resolve, only after a prolonged period; until totally reaching operating temp.
When I say (limp mode) I mean that the car throws dash lights: BAS/ESP, ETS, ABS and vehicle will not shift out of first gear. - Put that one in your pipe and smoke it. Please let me know what you come up with.
