FIRST CASE / VW LIMP MODE
Lately I've been having some issues with my Jetta 2.0T. She just suddenly went into
"limp mode" or
"safe mode" and it happened thrice during this week, resulting in total loss of power. I'm at my tether end, I have no idea what to do or how to rectify the situation. The first two times she went into
"limp mode" the
EPC warning light did not come on, however on the third occasion it came on and now stays on and hasn't gone off since. Initially I thought it was because the pump jockey threw-in LRP instead of unleaded fuel but I have since rectified the situation and its not that. I've run Vag-com diagnostics twice, which revealed the following data. I need help to repair this problem else I would have to take it to the service agents. Just the thought of a huge repair bill kept me from going there in the first place.
(First scan)
Control Module Part Number: 1K0 907 115 B
Component Version: 2.0l R4/4V TFSI 00 0010
1 Fault Found:
000818 - Knock Sensor 2 (G66): Signal too Low
P0332 - 002 - Lower Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 00100010
Fault Priority: 0
Fault Frequency: 2
Mileage: 18745 km
Time Indication: 0
Date: 2015.01.12
Time: 14:41:21
Freeze Frame:
RPM: 2555 /min
Load: 86.1 %
Speed: 52.0 km/h
Temperature: 77.0°C
Temperature: 39.0°C
Absolute Pres.: 1001.0 mbar
Voltage: 14.323 V
Readiness: 0000 0000
(second scan)
Address 01: Engine
Part No SW: 1K0 907 115 B HW: 1K0 907 115 B
Component: 2.0l R4/4V TFSI 00 0010
1 Fault Found:
000818 - Knock Sensor 2 (G66): Signal too Low
P0332 - 002 - Lower Limit Exceeded - Intermittent
Freeze Frame:
Fault Status: 10100010
Fault Priority: 0
Fault Frequency: 2
Mileage: 18992 km
Time Indication: 0
Date: 2015.01.15
Time: 12:05:11
Freeze Frame:
RPM: 2444 /min
Load: 57.1 %
Speed: 61.0 km/h
Temperature: 89.0°C
Temperature: 45.0°C
Absolute Pres.: 989.0 mbar
Voltage: 12.066 V
Readiness: 0000 0000
EXPLANATION
Our fellow VW owner is concerned with the different results of his two scans. So first and foremost let me assure him that there is nothing to worry about because the Readiness passes with flying colour. Readiness is the operational status of the 8 emission functions, viz the (1st nought) Exhaust Gas Recirculation - EGR, (2nd nought) Oxygen Sensor Heater, (3rd nought) Oxygen Sensor, (4th nought) Air Conditioning, (5th nought) Secondary Air Injection System, (6th nought) Evaporative Emissions System, (7th nought) Catalyst Heating and (8th nought) Three Way Catalyst. However, not all vehicles are fitted with all 8 system. If the system is absent, the report default to a 0 but a 1 signifies a fault in the respective system. The RPM, load, Speed and Temperature above, are all relative to how long the engine has been running, the gradient of the road etc. The Absolute Pres of 989.0 mbar is lower in scan two than the Absolute Pres. of 1001.0 mbar of scan one because the battery is lower. The optimum battery voltage is 14.4V. Anyway, to get back to the
"limp mode" issue at hand. I am almost certain the cause of
"limp mode" in this case is the Knock Sensor 2 (G66) because of Signal too Low - lower than expected by the ECU. The mere fact that the ECU reports a low signal implies that the wiring from the knock sensor to the ECU is intact and that the actual fault could be the knock sensor or the ECU itself . It is highly unlikely that the ECU is at fault because they are fairly robust, which leaves us with the knock sensor. Knock Sensors are torqued to the engine block for flush contact so that it would pick up the maximum amount of vibration. Should the bolt securing the Knock Sensor come loose, the knock sensor would send a lower signal than expected.
See previous blog Knock Sensor issue. Since the ECU cannot protect the engine in the absence of knock sensor 2 it decided to enter into
"limp mode" to safeguard the engine from possible damage it a knock developed or vibrations exceeded the prescribed limit.
_______________________________________________
SECOND CASE / VW LIMP MODE
I have a 9N - VW Polo and my car's EPC warning light comes on when I rapidly accelerate when driving at slow speeds or when accelerating rapidly while driving a steady speed. When the EPC warning light comes on, the car goes into
"limp mode" at that very moment then he check engine light comes on. I’ve scanned the ECU with VAG-COM and after spending hours under the bonnet looking for a possible cause, I still haven't found anything and need help or any suggestions so I can fix this problem.
Address 01: Engine
Part No: 036 906 034 FJ
Component: MARELLI 4MV 4830
3 Faults Found:
17961 - Barometric / Manifold Pressure Signals
P1553 - 35-10 - Implausible Correlation - Intermittent
17912 - Intake Air System
P1504 - 35-10 - Leak Detected - Intermittent
17550 - Load Calculation Cross Check
P1142 - 35-10 - Lower Limit Exceeded - Intermittent
Readiness: 0000 0101
EXPLANATION
The fact that the Readiness failed (see explanation above) more than explains why you are having car trouble. Since the 6th nought is a 1, it says that your Evaporative Emissions System (EVAP) is faulty. The 8th nought is also a 1, which says that your Three Way Catalyst is at faulty. However, in your case it appears that hardware upstream of the catalytic converter is causing the readiness to fail. The problems are associated with Leaks Detected in the Mass Air Flow (MAF) / Intake Air System / Barometric / EVAP system . Since the incorrect amount of air needed for stoichiometric calculations is inadequate, the fuel is not completely burnup and as a result the catalytic converter detects unburnt fuel and flags an error. The units themselves may not be faulty but rather the wiring and connectors of these units or cracks or cuts in the rubber hoses. Repairing these should take priority because OBD-II is designed to shut the car down if it fails readiness and there therefore the minimum emission standards. Since the fuel is under pressure and the rubber hoses could be leaking fuel, safe mode (limp mode) is initialised.
_______________________________________________
THIRD CASE / VW LIMP MODE
What is limp mode? My 6L-Seat Ibiza can idle but not rev, I think it has gone into limp mode, please help before I set this cas alight. Please explain what is limp mode? And how to fix limp mode. Here is the VAG-COM scan of modules with faults,
Address 01 ----------------------------------------------
Controller: 038 906 019 NF
Component: 1,9l R4 EDC 0000SG 5839
2 Faults Found:
18043 - Powertrain Data Bus: Missing Message from A/C Controller
P1635 - 35-10 - - - Intermittent
18045 - Powertrain Data Bus: Missing Message from Electronic Load Controller
P1637 - 35-10 - - - Intermittent
Readiness: N/A
Address 03 ----------------------------------------------
Controller: 6Q0 907 379 S
Component: MABS 8.0 front H03 0001
Coding: 0000008
Shop #: WSC 06441
Note: Excessive Comm Errors
Address 08 ----------------------------------------------
Controller:
Note: Excessive Comm Errors
EXPLANATION
For an explanation of what limp mode is, read the above. The two engine faults signify there could be a problem with the Data bus Wiring since neither the Electronic Load Controller nor the A/C Controller can send and receive messages. Coupled to the fact that Address 3 - ABS braking system and Address 8 -Auto HVAC both have Excessive Comm Errors, further verifies trouble with the Data bus. However it is more likely Fuses and /or Connector(s) from / to Central Electronics Control and the Gateway controller. The fact that the ECU cannot coordinate torque and braking it was best to shut the systems down and enter into safe mode
(limp mode) since malfunction of these important systems may lead to an accident and for the very least make for a poor driving experience.
_______________________________________________
FOURTH CASE / VW LIMP MODE
I have a Skoda Fabia and I think there is problems with the butterfly of my throttle body or perhaps it is dirty because the car goes into
"limp mode" continually. I have given up on kickdown because it is getting dangerous because whenever I want to overtake, my car goes into
limp mode. I would appreciate your commentary and your recommendations because
"limp mode" frustrates me and I curse all the time. Do you think the sensors are causing all my problems? Here is my Vag-com scan.
Address 01: ----------------------------------------------
Engine
Part No: 036 906 034 BL
Component: MARELLI 4LV 3699
Coding: 00071
No fault code found.
Readiness: 1110 0101
Address 08: ----------------------------------------------
Auto HVAC
Part No: 6Y0 820 045
Component: Klimaanlage X0760
1 Fault Found:
00818 - Sensor for Evaporator Outlet Temperature (G263)
30-00 - Open or Short to Plus
Address 09: ----------------------------------------------
Cent. Elect.
Part No: 6Q1 937 049
Component: BORDNETZ-SG.1S30
3 Faults Found:
00906 - Horn (H1)
28-10 - Short to Plus - Intermittent
00778 - Steering Angle Sensor (G85)
49-00 - No Communications
01324 - Control Module for All Wheel Drive (J492)
49-00 - No Communications
Address 15: ----------------------------------------------
Airbags
Part No: 1C0 909 601 C
Component: 02 AIRBAG VW51 01
1 Fault Found:
00532 - Supply Voltage B+
07-10 - Signal too Low - Intermittent
Address 19: ----------------------------------------------
CAN Gateway
Part No: 6N0 909 901
Component: Gateway K<->CAN 1S30
2 Faults Found:
00778 - Steering Angle Sensor (G85)
49-00 - No Communications
01324 - Control Module for All Wheel Drive (J492)
49-00 - No Communications
Address 44: ----------------------------------------------
Steering Assist
Control Module Part Number: 6Q0 423 156 AB
Component and/or Version: LenkhilfeTRW V270
Software Coding: 10140
1 Fault Found:
00816 - Power Steering Sensor (G250)
30-10 - Open or Short to Plus - Intermittent
EXPLANATION
This Skoda Fabia seems to have enough problems for half a dozen cars. Once again we need to look at Readiness first because it is quite evident that there more 1's than 0's. That tells us there are problems in the (1st nought) Exhaust Gas Recirculation - EGR, (2nd nought) Oxygen Sensor Heater, (3rd nought) Oxygen Sensor, (6th nought) Evaporative Emissions System and (8th nought) Three Way Catalyst. This is reason enough for the car to go into limp mode. But since it also has issues with its Steering Angle Sensor (G85)
and the Control Module for All Wheel Drive (J492) there is even more reason to shut the important systemes down and do into safe mode
(limp mode). There are also several electrical issues with open circuits and short circuits which would most likely be wiring harness related. But the most striking thing is the Low - Intermittent Supply Voltage B+ which implies the
battery terminal is loose. Intermittent supply voltage resets all modules all the time and can lead to spurious DTC.