A 2017 Skoda Kodiaq rolled in with a check engine light and a single P164700 fault code stored in the system. The technician noted the dashboard warning, but on these MQB platform vehicles, a P164700 is rarely a sign of a failed mechanical component. It is a manufacturer-specific VAG code indicating a logic conflict in the drivetrain control modules. When a vehicle flags this specific error, we are looking at an issue where the control units are failing to recognize each other's operating parameters. In the diagnostic platform we build, we see that diagnosing this code requires a strict sequence of software and network checks before any hardware is condemned. Finding the root cause efficiently dictates whether a diagnostic job is profitable or if it ends up tying up a bay for days.
The Software Version Management Conflict
The most probable cause for this specific fault code is a software incompatibility between the drivetrain control units, specifically a Software Version Management deviation. In this Skoda Kodiaq, the engine control module is a Bosch EDC17C74 unit managing the DFGA engine, designated as J623. It communicates continuously with the J743 DSG DQ381 transmission control module and the J533 Central Gateway.
These modules expect to see specific software versions that match a factory matrix. If the engine control module recently received an update during a service campaign, or if an aftermarket tuning file was applied, the software versions will no longer match the expected pairing in the transmission and gateway modules. The modules perform periodic validations of torque requests and emissions parameters during steady highway driving. When the software versions do not align, this validation fails, the system flags a version incompatibility, and the engine light illuminates. The light often goes out on subsequent drive cycles if the specific validation conditions are not met, creating a frustrating intermittent symptom for the workshop to trace.
Finding this deviation requires a systematic approach. The first test is to check the software versions and the calibration identification numbers (CALID/CVN) in both the J623 and J743 modules. You then need to read the Software Version Management history and compare it against the current factory matrix for the DFGA engine. If there is a mismatch, the fix involves performing a synchronization via ODIS connected to the manufacturer server. Chasing wiring or sensors without checking these software IDs will waste hours of valuable diagnostic time.
Long Coding and Equipment Mismatches
If the software versions match the factory matrix, the next area to investigate is an incorrect long coding string or a flawed Gateway installation list. The Gateway and the engine control module on the MQB platform are strictly coded to the exact equipment configuration of the vehicle. This includes the specific gearbox type, the presence of a four-wheel-drive system, adaptive cruise control, and the exact braking system installed at the factory.
A long coding conflict usually happens when manual coding has been attempted by a previous shop or the owner. A common example is trying to disable the Start/Stop system by altering the voltage limits in the Gateway. Incorrect variant coding for cruise control or installing replacement modules without performing an online coding procedure will also break this logic chain. During a drive cycle, the control module runs periodic routines to match its coded functions against the actual physical nodes responding on the CAN bus. When a parameter in the long coding string does not match the actual equipment, it triggers the P164700 code.
To rule this out, you need to check and reload the installation list in Gateway Address 19. You must compare the long coding string in the J623 module directly against the vehicle production numbers and the factory configuration. Resetting the adaptation channels in the Gateway back to their factory values is often necessary to clear out incorrect manual inputs. This process ensures the digital foundation of the vehicle matches the physical hardware bolted to it.
High-Speed Network Degradation
Software is not the only way to trigger a version or coding fault. Contact resistance or signal interference on the drivetrain CAN network can mimic a software incompatibility. The drivetrain CAN bus operates at a high speed of 500 kilobits per second, linking the engine, transmission, and gateway modules together.
Over years of thermal cycling in the engine bay, constant vibration at highway speeds, and potential moisture ingress, the physical connections can degrade. Intermittent contact resistance often develops at the main connector to the J623 module or in the wiring harness running between the engine bay and the cabin. The system sends cyclical control messages carrying version identification and torque validation data. If degraded wiring causes data packets to drop, the engine control module interprets the missing data as a version or data validation error, setting the P164700 code.
Testing the physical network requires checking the CAN termination resistance. With the battery completely disconnected, you should measure exactly 60 Ohms across the network. You also need to use an oscilloscope to measure the signals on the CAN High and CAN Low lines while physically vibrating the wiring harness to expose intermittent drops. Finally, a visual inspection of the connectors at the J623 and J743 modules for pin tension and corrosion is required before moving forward.
Micro-Hybrid Voltage Instability
A less obvious but critical factor is voltage instability originating from the 12-volt starting battery or the charging regulation system. The 2.0 TDI engine in this Skoda utilizes an energy recovery system, functioning as a micro-hybrid setup. The alternator charging voltage is dynamically regulated between 12.2 volts and 14.8 volts depending on whether the vehicle is accelerating or coasting.
As the AGM or EFB battery ages, its internal resistance increases. When the vehicle makes a rapid transition from engine braking to steady cruising, the sudden shift in charging demand can create transient voltage drops if the battery cannot buffer the change. These microscopic voltage fluctuations can cause brief communication interruptions during the periodic validations between the Gateway and the engine control module. The result is a sporadically set P164700 code that seems to have no obvious trigger.
Diagnosing this requires testing the state of health and cold cranking amps of the 12-volt battery using a conductance tester. You should also read the live battery data in Gateway Address 19, specifically looking at the state of charge and the measured internal resistance. Verifying the voltage stability under heavy acceleration and engine braking will confirm if the electrical foundation is solid enough to support the high-speed network communications.
Rethinking the Diagnostic Sequence
Modern vehicle diagnostics increasingly require workshops to verify software versions and network integrity before looking at a mechanical component. A code like P164700 is a perfect example of how a logical conflict can mask itself as a hard fault. By checking the Software Version Management matrix and long coding first, you prevent your technicians from tearing into wiring harnesses unnecessarily. Do you see similar software and coding conflicts eating up diagnostic time in your own bays?