Help! W204 C220 CDI Strange Issues

[bm2amb]

Hi,
I got a 2009 W204 C220 CDI diesel. There are two issues with it which started since Jan this year (2023)

1. On Jan 2023, I was driving at the highway (110km), the car will suddenly loose power and "ESP currently unavailable" will come up on the dash. the car will not rev over 1500 rpm, (limp mode ?). It clears only once you stop and switch it off and back on.

2. Since April, the car will loose drive for 1-2 seconds. Intermittently the car will just loose power - it can happen going fast or slow, car can be warm or cold.. it just cuts the power then after 1 or 2 seconds it goes fine, engine light went on for 24hrs, then disappeared. I took to the workshop, they changed the engine and fuel related relay, but it happens again after 4 weeks, because the fault is totally intermittent, the workshop has spend a lot of time to test, which caused a lot money on labor and did not the fix the problem

I bought a OBD reader, it happens again today. I have attached the DTC log, the workshop think its not the startup relay issue (because I always start may car without issues), also don't think its fuel regulator issue. I just don't want to spend lots of $$$ for someone spend half day to test and change out all the working parts and not resolve the issue.

anyone got similar experience ? Thanks

============================
OBD-IIOBD-II
DTCs: 9
----------------------------
P0615 [0x0615]
Starter motor relay - circuit malfunction
Status: Confirmed
----------------------------
P0091 [0x0091]
Fuel pressure regulator 1 - short to earth; Fuel Pressure Regulator 1 Control Circuit Low Voltage
Status: Confirmed
----------------------------
P0615(00) [0x061500] Archive (inactive)
Starter motor relay - circuit malfunction
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0597(00) [0x059700] Archive (inactive)
Thermostat heater control system - open circuit
Status: Confirmed, Test failed since last DTC clear
----------------------------
P2600(00) [0x260000] Archive (inactive)
Engine coolant pump motor - open circuit
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0091(00) [0x009100] Archive (inactive)
Fuel pressure regulator 1 - short to earth; Fuel Pressure Regulator 1 Control Circuit Low Voltage
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0244(13) [0x024413] Archive (inactive)
Turbocharger (TC) wastegate regulating valve A - range/performance problem
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0045(00) [0x004500] Archive (inactive)
Turbocharger (TC) boost control solenoid/supercharger (SC) boost control solenoid - open circuit
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0033(00) [0x003300] Archive (inactive)
Turbocharger (TC) bypass valve - circuit malfunction
Status: Confirmed, Test failed since last DTC clear
============================
Engine control unitEngine control unit
DTCs: 7
----------------------------
P0615(00) [0x061500] Archive (inactive)
Starter motor relay - circuit malfunction
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0597(00) [0x059700] Archive (inactive)
Thermostat heater control system - open circuit
Status: Confirmed, Test failed since last DTC clear
----------------------------
P2600(00) [0x260000] Archive (inactive)
Engine coolant pump motor - open circuit
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0091(00) [0x009100] Archive (inactive)
Fuel pressure regulator 1 - short to earth; Fuel Pressure Regulator 1 Control Circuit Low Voltage
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0244(13) [0x024413] Archive (inactive)
Turbocharger (TC) wastegate regulating valve A - range/performance problem
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0045(00) [0x004500] Archive (inactive)
Turbocharger (TC) boost control solenoid/supercharger (SC) boost control solenoid - open circuit
Status: Confirmed, Test failed since last DTC clear
----------------------------
P0033(00) [0x003300] Archive (inactive)
Turbocharger (TC) bypass valve - circuit malfunction
Status: Confirmed, Test failed since last DTC clear
============================
Transmission control unit
No DTC found.
============================
ABS control unitABS control unit
DTCs: 1
----------------------------
C2106 [0x6106] Archive (inactive)
Status: Validated and stored in non volatile memory

 

[bm2amb]

2019/Nov/13 New battery installed
2023/Jan/10 On the highway (110km), the car will suddenly loose power and "ESP currently unavailable" will come up on the dash. the car will not rev over 1500 rpm. However did not leave any DTC in the log
2023/Apr/09 Same thing happened again No EPS error this time, left DTC code: P0615 (Starter motor relay) and P0091 (Fuel pressure regulator 1)
2023/Apr/18 The car loose power in the car park, wouldn't crank up. after few mins it started again. (DTC same as OP)
2023/Apr/24 Workshop changed engine main relay, injection relay
2023/May/23 The car was suddenly shaked, and engine like came on. (DTC attached in OP)

It happened 4times in the past 5months, a bit more regular since Apr.