What causes the following faults code on 2004 volvo S40 :ECM-250A LONG TERM-FUEL TRIM:UPPER LIMIT,BCM-0100 COMMUNICATION PROBLEM WITH ECM,EPS-0082 ENGINE STATUS FAULTY SIGNAL,CCM-001 COMMUNICATION CONTROL MODULE;INTERNAL FAULT,DDM-E001 CONTROL MODULE COMMUNICATRION,INTERNAL FAULT

https://www.dtcdecode.com/Volvo/EPS-0082

You need to have someone scan the OBD system and tell you if the fuel trim is at the upper or lower limit. Then you will need to fault trace from the following list Possible source

• Upper limit:
  intake air leakage
  exhaust system air leakage
  defective heated oxygen sensor (HO2S)

Lower limit:

• intake air leakage
  high fuel pressure
  leaking injectors
  defective mass air flow (MAF) sensor
  contaminated engine oil
  oil level too high
  defective heated oxygen sensor (HO2S)

The ECM has numerous sensors that are read continuously and these results are checked against pre-set parameters in the CPU memories. Every possible cause of a fault code is an associated sensor that is being affected by the fault so there are several possible reasons that cause the fault . That is to say wiring is a possible cause ---the unit itself is another possible cause---low /high voltage is another and so on. Take it to a service centre as with most makes of vehicles there is a common fault problem that experienced technicians are aware of and can pin point quickly. As with advice from readers the causes are general areas of advice to look at so if it appears confusing then take it to an experienced shop.

Error description:
ECM-250A Long-term trim - Upper Limit

code 1600 refers to throttle position (TP) sensor-communication error. Cause wiring---poor connection---TP sensor---ESP control module---ECM
code 1000 refers to barometric pressure (BARO) sensor --signal high. Cause---wiring short to positive---BARO sensor.

Sound like a problem with the MAF sensor, try replace.

Pulled codes for ECM-250A long term fuel trim upper limit, inspected and found air mass sensor failing internally, should show 4 f/s at idle and is showing 2.98 f/s at idle. Recommend replacing with new.



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DTC P2187: Fuel Trim System Lean at Idle

Fuel Trim Description
The Engine Control Module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the ECM determines fuel delivery based on sensor signals without Heated Oxygen Sensor (HO2S) input. During Closed Loop, the HO2S inputs are added and used by the ECM to calculate short and long term fuel trim fuel delivery adjustments. If the HO2S indicate a lean condition, fuel trim values will be above 0%. If the Heated Oxygen Sensors (HO2S) indicate a rich condition, fuel trim values will be below 0%. Short term fuel trim values change rapidly in response to the HO2S signals. Long term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7 : 1.

This code can only set when the engine control is in Closed Loop. The engine must be fully warmed up.

This must be diagnosed using a scan tool that can read engine data in order to determine the actual cause of the problem. It can be caused by the following things:

> Vacuum leaks
> Malfunctioning, dirty, or skewed Mass Airflow Sensor (MAF)
> Malfunctioning or skewed Manifold Absolute Pressure Sensor (MAP)
> Dirty or sticking injectors
> Malfunctioning or improperly programmed Powertrain Control Module (PCM)

The control module receives information from the heated oxygen sensor (HO2S) about the fuel/air mixture when idling at both the lower and upper part-load range - If the fuel/air mixture deviates from [lambda]=1 the short-term fuel trim will compensate for this by adjusting injection time so that [lambda]=1 is achieved. When the short-term fuel trim makes an adjustment, the integrator median must be adjusted by the long-term trim. Diagnostic trouble code (DTC) ECM-261A will be stored when the long-term trim must be adjusted to maximum in the lower part of the load area.

p0172 is not a volvo code so may not be correct but converted to volvo is code 250a long term fuel upper limit (lean vac leak) ck all vac hoses and replace the canister purge valve mounted on the radiator (about $40.00 part) then reset all codes

Faults can happen from day one, on. That is why there is a warning system.
If the warning light is on, you must access the computer system to access which fault code is present. Many different companies manufacture tools to do this from an inexpensive generic one from Launch Tech of China to the original factory unit made for Volvo by Balco. Depending on the fault code, the most common one that I see is caused by the fuel cap either installed incorrectly or not fully tightenned. Check your fuel cap and if it is not installed correctly or not fully tightenned, please re-install. If the fuel cap was the problem, the warning light will go off by itself in a few days.