Answer
Apr 28, 2023 - 04:00 AM
Unfortunately, there is no simple answer to this question.
Indeed, pretty much any kind of malfunction or failure could cause the engine to get into Limp mode. As a general rule, I'd say that anything that could either damage the engine or hurt the occupant could trigger the Limp mode.
For instance, a discrepancy between the Throttle Position Sensor (TPS) and the Accelerator Pedal Position (APP) sensor could potentially cause the engine to accelerate without the driver stepping on the gas pedal. As a result, as soon as the Electronic Control Module detects a difference between both input signals, it triggers the engine to enter the Limp mode.
Another example is if the engine was to detect several misfires happening at the same time, the same would also apply to incorrect signals from the transmission sensors, etc.
In short, if your engine is stuck in Limp mode, there's usually a good reason for it. However, unless you run a quick scan and read the Diagnostic Trouble Codes (DTCs) recorded in the control modules, there's really no way of knowing what could be the issue here.
Luckily, once you've pulled those codes, you'll find every troubleshooting and repair procedure you might need to find and fix the problem in this 2004 Mercedes-Benz E-Class E240 (W211) OEM Download Service & Repair Manual Software.
