IMMOBILIZER

VW, AUDI, SKODA & SEAT IMMOBILIZER PROBLEMS

The worst thing that can ever happen to you especially when you're in a hurry to get to an appointment on time,  is to turn-on your car's ignition key and see a yellow immobilizer symbol (car with a key below it) flashing in your instrument cluster accompanied by a fairly loud ear piecing audible signal. When you witness this, your car isn't going to go anywhere and neither are you. I suppose there are worst scenarios you could be in like when you stop along a dark and lonely road at night, compelled to take a pee, only to return to your car, to be met by the yellow flashing immobilizer symbol. There are so many VAG Vehicle owners who have experienced some sort of immobilizer problem with their cars and those drivers who haven't, I'm so sorry to say, but its only a matter of time before you do. That sounds very pessimistic, but once again, I'm sorry to say but that's the reality of the situation. It is what it is.

The dreaded Immobilizer symbol

Looking through my database of immobilizer issues, some of which I have shared with you below, gives you a fair idea of what can be expected from your VAG vehicle in the future. VW, Seat, Skoda and Audi vehicles comes out with a various versions of theft deterrent software systems, starting with vehicles without an Immobilizer (Pre 1995),   to Immobilizer I (Immo I - 1996), to Immobilizer II (Immo II - 2002+), to Immobilizer III (Immo III) aka Transponder III, to Immobilizer IV (Immo IV) and  the 5th generation Immobilizer (Immo V - 2011). There are also various Immobilizer hardware integrated into the instrument cluster, two of which are (J285 & J334 Immobilizer Control Module) and  (J285 & J362 Immobilizer Control Module).  Not to state the obvious, VAG cars are equipped with Anti-Theft Engine Disable immobilizers to circumvent theft; and should a car thief swap-out an ECU without matching it to instrument cluster, the engine will start briefly then die and this will be repeated indefinitely. 

AUDI, SEAT, SKODA and VW AVITARS

Since the implementation of Immo 3, variable code evaluation is use in both  the engine control unit and Immobilizer control unit. They use an equation / algorithm that calculates the generated variable code that both control units must agree upon. So, if you ever start your car and it stalls after about 1 second, then its perfectly safe to suspect the Immobilizer as faulty whether it displays the immobilizer symbol or not.  In such a case  the DTC memory should be checked and, if necessary, the control module adapted. Whether or not the has Immobilizer disabled the ECU can be verified under address word 17, and or address word 25, using a scan tool like VCDS, ODIS,  Launch, Autoboss,  Autel MaxiDAS, etc. The data whether  ON or OFF, sits in measuring block 007 under Central locking. Most importantly the DTC are the clues that's going to point you in the right direction.

ODIS is the latest VW, AUDI SEAT SKODA, BENTLEY,
LAMBORGINI and PORSCHE Diagnostic Software.

So, when the ignition is switched ON, the Instrument cluster / Immobilizer Control Module enables or disables specific vehicle functions based on a hand shake. What this means is that when the switchblade key is pushed into the ignition lock, or placed in proximity of the  coil transmitted radio signal, the instrument cluster electronics detects the key and initiates a data transfer between the pickup coil in the steering column or ignition switch and the RFID (Radio Frequency Identification) capsule embedded in the fob key. If the correct / unique identification number / authorized security data stream is received at the Immobilizer Control Module it permits the engine to start and idle uninhibited. But if it doesn't the car wont start.

RFID capsules are tiny, it stores data unique to your car  and can be found inside your fob key.

The list below constitutes just a smatter of immobilizer errors that VAG car owners can experience, which range from a low fob key battery, to an instrument cluster or ECU replacement. And somewhere in between you will have, wiring harness issues ranging from intermittent to open circuit and even short circuit. Active RFID tags have their own power source whereas passive RFID tags used in all fob keys don't require power. 
Essentially they consist of a scanning antenna, a  transceiver with a decoder to interpret the data and  a transponder - the RFID tag - that has been pre-programmed with the relevant information specific to your VIN, ECU and Instrument cluster. A dry joint on the pickup coil inside the capsule can prevent the necessary hand shake thus its a good idea to have a second matched fob key available if the key that won't start the car is suspect. In the list below, you also find appropriate codings for  Immobilizer Module address 25 and as  can be clearly seen, different control modules have different ODX/ASAM datasets, different software versions and different .rod files. Before changing any codes, make certain that you have a printed copy of all existing codes.

Immobilizer DTCs, Immobilizer Errors, Immobilizer Problems & Codes 

Address 25: Immobilizer
   Cannot be reached
--------------------------------------------------
Address 25: Immobilizer
   unobtainable
--------------------------------------------------
Address 25: Immobilizer      
   DTCs not supported by controller
   or a communication error ocurred
--------------------------------------------------
Address 25: Immobilizer      
   16897 - Incorrect Immobilizer code
   P0513 - 35-00 - Malfunction in Circuit
   17978 - Motronic Engine Control Module (ECM) -J220- Electronically locked
   P1570 - 35-00 - Malfunction in Circuit
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6X0 953 257
   Component: IMMO 0008
   Coding: 00001
   Excessive Comm Errors
--------------------------------------------------
Address 25: Immobilizer
   Control unit: 6Y0 920 883 M
   Component: IMMOBILIZER VDO V04
   Coding: 00102
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6Q0 920 825 E
   Component: IMMOBILIZER VDO V06
   Coding: 03144
   01176 - Key
   07-00 - Signal too Low
--------------------------------------------------
Address 25: Immobilizer      
   Part No SW: 1K0 920 874 JX    HW: 1K0 920 874 JX
   Component: IMMO            3HL 2416
   Revision: V0005000    Serial number: VWX7Z0G524F0LU
   01176 - Key
   008 - Implausible Signal - Intermittent
--------------------------------------------------
Address 25: Immobilizer      
   Controller: 6H0 953 257 B
   Component: IMMO VWZ3Z0X1234088 V71
   Coding: 09600
   01176 - Key
   65-10 - Unauthorized - Intermittent
--------------------------------------------------
Address 25: Immobilizer      
   Controller: 038 906 019 DQ
   Component: 1,9l R4 EDC 0000SG 1536
   Coding: 00002
   17978 - Engine Start Blocked by Immobilizer
   P1570 - 35-00 - Malfunction in Circuit
   16989 - Internal Control Module: ROM Error
   P0605 - 35-00 - Implausible Signal
--------------------------------------------------
Address 25: Immobilizer      
   Controller: 4A0 953 234 F
   Component: IMMO AUZ9Z0T7884365 D77
   Coding: 00000
   01176 - Key
   07-10 - Signal to Low - Intermittent
   00750 - Warning Lamp
   31-10 - Open or Short to Ground - Intermittent
--------------------------------------------------
Address 25: Immobilizer  
   Part No: 6L0 920 803 E
   Component: IMMOBILIZER     AGD V05
   Coding: 00105
   01177 - Engine Control Unit
   65-10 - Unauthorized - Intermittent
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6X0 953 257
   Component: IMMO 0003
   Coding: 00003
   00750 - Warning Lamp
   31-00 - Open or Short to Ground
   01314 - Engine Control Module
   49-10 - No Communications - Intermittent
   01176 - Key
   65-10 - Unauthorized - Intermittent
--------------------------------------------------
Address 25: Immobilizer
   Part No: 4A0 953 234
   Component: IMMO AUZ9Z0W5254731 D77
   Coding: 00000
   01176 - Key
   07-10 - Signal too Low - Intermittent
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 1T0 920 873 E HW: 1T0 920 873 E
   Component: IMMO VDD 3808
   Revision: V0001000 Serial number: VWX7Z0G33ND1A0
   00003 - Control Module
   014 - Defective
--------------------------------------------------
Address 25: Immobilizer
   Part No: 1H0 953 257 B
   Component: IMMO VWZ3Z0M2519376 V00
   Coding: 09600
   00546 - Data wiring faulty
   27-00 - Implausible Signal
--------------------------------------------------
Address 25: Immobilizer       (J334)
Part No SW: 5K0 953 234 HW: 5K0 953 234
Component: IMMO H03 0607
Serial number: 00000000000000
Coding: 000000
ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03009
ROD: EV_Immo_UDS_VDD_RM09_SE36.rod
9456681 - Key
B104C 29 [009] - Implausible Signal
Confirmed - Tested Since Memory Clear
--------------------------------------------------
Address 25: Immobilizer
Part No: 1H0 953 257 B
Component: IMMO VWZ3Z0E1731908 V00
Coding: 09600
00546 - Data wiring faulty
27-00 - Implausible Signal
01181 - Initializing; Only 2 Keys Learned
35-00 - Implausible Signal
01179 - Incorrect Key Programming
35-00 - Implausible Signal
--------------------------------------------------
Address 25: Immobilizer
Part No: 1K0 920 960 L
Component: IMMO 3354
02241 - Engine Control Module; Immobilizer Data not Adapted
000 - - - Intermittent
--------------------------------------------------
Address 25: Immobilizer
Part No SW: 3C0 959 433 H HW: 3C0 959 433 H
Component: IMMO 038 0364
Revision: 00038000 Serial number: VWZCZ000000000
Part No: 3C0 905 861 C
Component: ELV 023 0350
3C0905861C ELV 023 0350
02823 - Requirements for Locking the Steering Column Lock not met
000 - - - Intermittent
02861 - Electronic Steering Column Lock Check Sum Error
008 - Implausible Signal - Intermittent
02815 - Steering Column Lock; Supply Voltage for Locking Motor
002 - Lower Limit Exceeded - Intermittent
02817 - Steering Column Lock; Enabling Wire from Steering Wheel Electronics
002 - Lower Limit Exceeded - Intermitten
02818 - Steering Column Lock; Enabling for Electronic Ignition Lock
009 - Open or Short to Ground
02811 - Control Module for Electronic Steering Column Lock (J764)
014 - Defective - Intermittent
--------------------------------------------------
Address 25: Immobilizer
Part No: 2K0 920 941 CX
Component: IMMO VDD 0716
--------------------------------------------------
Address 25: Immobilizer
Part No: 1P0 920 825 B
Component: IMMO VO3 0424
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6Q0 920 923 Q
   Component: IMMOBILIZER VDO V03
   Coding: 01444
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6Q0 920 923 R
   Component: IMMOBILIZER VDO V02
   Coding: 01432
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6Q0 920 903 J
   Component: IMMOBILIZER VDO V06
   Coding: 01431
--------------------------------------------------
Address 25: Immobilizer      
   Controller: 6Q0 920 825 E
   Component: IMMOBILIZER VDO V03
   Coding: 01144
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6Q0 920 825 F
   Component: IMMOBILIZER AGD V05
   Coding: 01132
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6Q0 920 804
   Component: IMMOBILIZER VDO V06
   Coding: 01131
--------------------------------------------------
Address 25: Immobilizer (J334)
   Part No SW: 5K0 953 234 HW: 5K0 953 234
   Component: IMMO H04 0406
   Serial number: 00000000000000
   Coding: 000000
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03008
   ROD: EV_Immo_UDS_VDD_RM09_SE25.rod
--------------------------------------------------
Address 25: Immobilizer (J334)
Part No SW: 6J0 920 901 A    HW: 6J0 920 901 A
Component: IMMO          X07 0110
Serial number:            
ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03004
ROD: EV_Immo_UDS_VDD_RM09_SE25.rod
--------------------------------------------------
Address 25: Immobilizer (J334)
Part No SW: 6R0 920 861 B HW: 6R0 920 861 B
Component: IMMO H23 0110
Serial number:
ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03004
ROD: EV_Immo_UDS_VDD_RM09_VN35.rod
--------------------------------------------------
Address 25: Immobilizer (J334)
   Part No SW: 5K0 953 234 HW: 5M0 920 960 E
   Component: IMMO H14 0112
   Revision: X0014004 Serial number:
   Coding: 000000
   ASAM Dataset: EV_ImmoUDSMM9RM10 A01102
   ROD: EV_ImmoUDSMM9RM10.rod
--------------------------------------------------
Address 25: Immobilizer (J334)
Part No SW: 5K6 920 970 G HW: 5K6 920 970 G
Component: IMMO H05 0206
Serial number: 00000000000000
ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03004
ROD: EV_Immo_UDS_VDD_RM09_VW36.rod
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 3C0 959 433 AR    HW: 3C0 959 433 AR
   Component:    IMMO         043 0383
   Revision: 00043000    Serial number: VWZCZ000000000
   Part No: 3C0 905 861 H
   Component:    ELV          028 0380
   3C0905861H    ELV          028 0380
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 1K6 920 974 H    HW: 1K6 920 974 H
   Component: IMMO            VDD 2416
   Revision: V0003000    Serial number: VWX7Z0H43NL82Z
--------------------------------------------------
Address 25: Immobilizer
Controller: 6X0 953 257
Component: IMMO 0007
Coding: 00001
--------------------------------------------------
Address 25: Immobilizer
Part No: 5P0 920 825 A
Component: IMMO VO3 0422
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 1Z0 920 912 E    HW: 1Z0 920 912 E
   Component: IMMO            VD1 1610
   Revision: V1610056    Serial number: SKZ7Z0G4047329
--------------------------------------------------
Address 25: Immobilizer (J334)
Part No SW: 5K0 953 234 HW: 5K0 953 234
Component: IMMO H03 0505
Serial number:
Coding: 000000
ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03009
ROD: EV_Immo_UDS_VDD_RM09_VW25.rod
--------------------------------------------------
Address 25: Immobilizer
Part No SW: 8P0 920 931 HW: 8P0 920 931
Component: KOMBIINSTR. VDO H18 0560
Revision: D0H18002 Serial number: AUX7Z0F6FN5049
-------------------------------------------------
Address 25: Immobilizer
Controller: 6X0 953 257
Component: IMMO 0003
Coding: 00001
--------------------------------------------------
Address 25: Immobilizer
Controller: 6X0 953 257
Component: IMMO 0008
Coding: 00001
--------------------------------------------------
Address 25: Immobilizer (J334)
   Part No SW: 5K0 953 234     HW: 5K0 953 234
   Component: IMMO          H07 0705
   Serial number: 00000000000000
   Coding: 000007
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03709
   ROD: EV_Immo_UDS_VDD_RM09_SE36.rod
--------------------------------------------------
Address 25: Immobilizer (J334)
   Part No SW: 5K0 953 234 HW: 5K0 953 234
   Component: IMMO H07 0308
   Serial number:
   Coding: 000000
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03005
   ROD: EV_Immo_UDS_VDD_RM09_SE35.rod
--------------------------------------------------
Address 25: Immobilizer (J334)
   Part No SW: 5K0 953 234 HW: 5K0 953 234
   Component: IMMO H03 0607
   Serial number:
   Coding: 000000
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03009
   ROD: EV_Immo_UDS_VDD_RM09_VW36.rod
--------------------------------------------------
Address 25: Immobilizer (J334)    
   Part No SW: 6J0 920 901 A    HW: 6J0 920 901 A
   Component: IMMO          X07 0110
   Serial number:            
   ASAM Dataset: EV_Immo_UDS_VDD_RM09 A03004
   ROD: EV_Immo_UDS_VDD_RM09_SE25.rod
--------------------------------------------------
Address 25: Immobilizer
   Part No: 1P0 920 904 C
   Component: IMMO VO3 0422
--------------------------------------------------
Address 25: Immobilizer
   Controller: 6X0 953 257
   Component: IMMO 0008
   Coding: 00001
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6Q0 920 903 J
   Component: IMMOBILIZER VDO V06
   Coding: 01431
--------------------------------------------------
Address 25: Immobilizer
   Part No: 6Q0 920 923 R
   Component: IMMOBILIZER VDO V06
   Coding: 01432
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 1K0 920 953 P HW: 1K0 920 953 P
   Component: IMMO 3HL 1610
   Revision: V0003000 Serial number: VWZ7Z0G9079540
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 3AA 959 433 HW: 3AA 959 433
   Component: IMMO 043 0399
   Revision: 00043000 Serial number: VWZCZ000000000
   Subsystem 1 - Part No: 3C0 905 861 J
   Component: ELV 029 0380
   3C0905861J ELV 029 0380
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 3C0 959 433 AQ    HW: 3C0 959 433 AQ
   Component:    IMMO         044 0383
   Revision: 00044000    Serial number: VWZCZ000000000
   Part No: 3C0 905 861 G
   Component:    ELV          027 0380
   3C0905861G    ELV          027 0380
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 8P0 920 981 A HW: 8P0 920 981 A
   Component: KOMBIINSTR. VDO H73 0300
   Revision: D04 Serial number: AUX7Z0E1FNG04N
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 8P0 920 900 F HW: 8P0 920 900 F
   Component: KOMBIINSTR. VDO H72 0210
   Revision: D03 Serial number: AUX7Z0D9FND0BK
--------------------------------------------------
Address 25: Immobilizer
   Part No SW: 8J0 920 980 G HW: 8J0 920 980 G
   Component: KOMBIINSTR. VDO H02 0480
   Revision: D0H02002 Serial number: AUX7Z0I4FNJ115
--------------------------------------------------
Address 25: Immobilizer  
   Part No SW: 1K0 920 974 N    HW: 1K0 920 974 N
   Component: IMMO            3HL 2418
   Revision: V0003000    Serial number: VWX7Z0H824U00R

TRANSMISSION LIMP MODE

TRANSMISSION LIMP MODE 

During the late 1970's to the early 1980s, the on-board computer made its first appearance, responsible for monitoring and controlling the vehicle's engine. It started out with better fuel economy in mind,  followed by a  electronic capacitive discharge ignition systems (CDI), then electronic points and engine timing were introduced. Soon thereafter it encompassed anti-lock braking (ABS), airbags (SRS), climate control (HVAC), electronic stability control (ESP) and emissions control among several others. Today, virtually every subsystem in your vehicle is controlled by a computer  interfaced with sensors of sorts – including the automatic transmission’s shift timing sequence and line pressure.   The manifold absolute pressure (MAP) sensor and throttle position sensor (TPS), among several other, supplies the engine’s load signals and information which is used by the  Engine Control Unit (ECU) to inform the Transmission Control Unit (TCU) when to manage gear up-shift and down-shift, especially when you’re driving up an incline or inclined toward spirited driving. Since there is so much electronics, there is so much more that can go wrong,  so a  "fail safe" system had to be employed as a safety feature just in case of signal errors  that occur  outside of its expected range.  A feature that would protect the engine / transmission from "runaway" that could cause it to self destruct. 

There is even an Electronic Pressure Control (EPC) valve safety circuit, integrated directly in the transmission hydraulic circuit of all VAG vehicles. When necessary, a part of the gearbox is depressurised to prevent any transmission clutches from closing uncontrolled due to  excessive clutch pressure. This is feature is called the "Emergency Program" aka "Limp Mode"  or "Limp Mode Home".

When your Audi, Volkswagen, Seat or Skoda's  EPC light,  and or the Check engine light,  and or DPF (Diesel Particulate filter) light turns on, your car is likely to go into limp mode, if  it hasn't  already entered into Limp mode. Other than the illuminated light or lights in the instrument panel, and an engine that will not rev more than 2000 revs, neither exceed 30 kph, it gives you absolutely no explanation why it happened.  To make matters worse, there is no definitive list of what causes this elusive limp mode but I have tabulated some of them from personal experience. 

How to fix limp home mode

• Throttle Pedal Sensors (TPS), G79/G185
• Throttle body Position sensors, G187/G188 
• Throttle Valve Control Module, J338
• Engine Component Power Supply Relay, J757
• Intermittent Ignition Coils, N, N128, N158, N163
• Fuel Injectors N30, N31, N32, N33
• Transmission Control Module J217
• Waste-gate Actuator Valve, N75
• Knock Sensor, G61 
• Fuel pressure sensor G247 
• Fuel pressure regulator valve, N276 
• Automatic transmission electronic pressure control (EPC )   solenoid / stuck solenoids
• Transmission solenoid harness

Volkswagen Automatic Transmission Solenoid and Harness kit.

The only way to repair an EPC fault (Limp Mode) or for that matter any fault on any VAG vehicle, is to do a DLC scan to pull the Diagnostic Trouble Codes (DTC) to at least point you in the right direction. One of the most miserable Limp mode experiences ever is a Transmission Limp Mode. They range from a transmission that is low on fluid, to stuck in 2nd gear, to jumping out of gear, to noisy gears selection. But the worst is when  engine antifreeze water from the radiator enters through the corroded ATF cooler lines into the transmission, also allowing the ATF to leak  into the engine coolant, radiator and engine. 

Knowing the Germans, their just had to be a oil cooler for the automatic gearbox integrated somewhere into the radiator. Even though VW claim that ATF is a lifetime fluid", it is only a matter of time before it mixes with antifreeze and water. Anyway, this happens to  the all-in-one radiators  of Volkswagen Jettas, VW Golf 4, Passat B6, Audi A4 Quattro  and I suspect other VAG vehicle which I havn't personally experienced. It also happens to the Mercedes Benz C250, but it's  not an exclusive German car design flaw. It s also prevalent in the Nissan Pathfinder, Fords and Pontiac as well as several Asian vehicles.

Once the oil cooler lines spring a leak inside the plastic radiator, it messes-up the entire system by mixing the anti freeze water mixture with ATF. Yet with all the vehicle on-board electronics there is no visible sign that this cross flow happened nor any electronic detection or indication. Since oil is less dense than water, the gears in the transmission runs in water which causes the  metal gears to rust besides taking  the facings off the clutch plates. Beside the water shorts out the printed circuit board driving the solenoids on the valve body. This type of extensive damage can result in a very expensive transmission replacement if it isn't detected before the damage is done. 

Volkswagen  valve body

An easy way to identify this problem, is to check the ATF dipstick level often, which needs to be between the two notches marking min and max. Much more than that can indicate ATF floating on water. Also verify that the colour of the ATF is translucent red and not brown or black. Bi-annual ATF replacement, though expensive should almost guarantee a trouble free transmission. The logic behind an all-in-one radiator ATF cooler is to heat-up the ATF with the hot radiator water during cold conditions because oil tends to become thick and gel when very cold.  But is may be in your interest to replace your all-in-one ATF cooler with a separate / free standing oil cooler as used in the new cars if you live in a country where it never snows or never experience freezing cold weather.

Universal Aluminum  after market Automotive 13-Roll Transmission Oil Cooler