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Audi EA837 Engine Water Temperature and Supercharger Failure

Audi V6 3.0T engine
Audi V6 3.0T Engine

Problem: V6 3.0T engine water temperature is high for models: (D4/Q7/C7/A7/A5)

Troubleshooting, inspection and repair.

  1. Use the diagnostic instrument to detect the P1B1C fault code – the mechanical failure of the coolant pump;
  2. The diagnostic report has no fault code, and the temperature of the simple thermostat is high;

Inspection and repair

The first case:

(1) According to TPI 2040838, first upgrade the SVM 02A210. If the thermostat is faulty, please replace it with the thermostat with the tail number AL (if you can refer to the chassis number below). The original vehicle fault is required for AL. Return the faulty parts to Changchun. At the same time, check the vacuum degree of the pump through the vacuum pump VAS6213. If the pump can not hold the pressure, please replace the pump at the same time;

(2) If the fault cannot be solved after the execution of (1), check the working condition of the vacuum solenoid valve and the water temperature sensor G62 at the same time, and replace if there is a fault;

The second case:

(1) If the thermostat is judged to be AD according to the chassis number, the thermostat is directly replaced with AL when the thermostat is confirmed to be faulty;

(2) If the thermostat after AL or AL is judged according to the chassis number, the SVM 02A210 should be used for the upgrade. If the fault still cannot be eliminated, it can be replaced with the thermostat after AL or AL.

When it is determined whether it is the AL thermostat without disassembling, it is first necessary to refer to whether the faulty vehicle has performed the 24AP action, or the maintenance history has been replaced or the AL thermostat;

V6 3.0T engine tail number AL thermostat measures chassis number (for reference only)

OBD alarm after V6 3.0T 24AP action

Failure phenomenon:

The V6 3.0T vehicle performs the OBD alarm after the 24AP action.


The diagnostic report has a P000000 fault code;

cause of issue:

(1) In the initial stage of 24AP operation, the software setting is slightly sensitive, resulting in driving for a period of time after the execution of 24AP due to the failure of the three-way catalytic converter to cause OBD alarm;

(2) It is necessary to check to see if it is a three-way catalytic converter damage or an OBD alarm caused by software alone. Germany has updated the upgrade software in 2015.5.24. Vehicles that have performed an action before 5.24 may attempt to upgrade again. If the fault cannot be eliminated or the action is performed after 5.24, the need to perform TPI 2040724 is required.

Check the repair:

(1) If the 24AP action is performed after 5.24, please save and send the diagnostic report containing the MVBs EFF_CAT_DIAG[1] + [2] data, and replace the three-way catalytic converter on both sides, send the mail to Shuo.feng@faw and;

(2) If the fault occurs after the 24AP action is performed before 5.24, first upgrade the SVM 02A210 according to TPI 2040724, and then perform the detection process according to the TPI (the conversion function detection of the exhaust gas catalytic converter), see TPI for details;

(3) If the OBD lamp still alarms after the test is completed, and the diagnosis report has “P000000 or P042000/P043000 cylinder column 1/2 exhaust gas catalytic converter system is too low efficiency”, the three-way catalytic converter must be replaced, and Reported to the Product Support Department;

Note: The fault code of P000000 is caused by the display problem. The fault code has no practical meaning. Actually, P042000 or P043000 should be displayed.

V6 3.0T EVO supercharger fault analysis

Failure phenomenon:

The V6 3.0T vehicle is in the manual shift mode. When the engine speed is slowly increased to 3000r/min, the engine will emit a metal knocking sound, and there will be noise, and the noise will disappear after more than 3000rpm.


Engine speed increase to 3000r/min, the engine runs normally without abnormal noise due to the nose cone.

Technical Information:

(1) Figure 2 is the on and off characteristic of the supercharger; the red region is in a low torque state and the clutch is disengaged. The clutch is engaged when the engine speed reaches 3000 rpm. The gray area engine is fully loaded and the clutch is engaged.

(2) Figure 1 shows the gearbox in short switching (engine acceleration, forced downshift), and gearbox length switching (slow acceleration, exceeding speed limit).

The armature of the electromagnetic clutch and the rotor begin to contact at an engine speed of approximately 3000 rpm, and the current sensor in the engine control unit begins current regulation at this time. (The rotational speed of the rotor is transmitted as an input signal to the synchronizing gear of the supercharger via the sensor).

When switching shortly, the engine speed is increased fast, the corresponding supercharger speed is increased fast, and the clutch current stays in the adjustment area for a short time;

When switching long, the engine speed is slowly increased and the turbocharger speed is slowly increased. When the rotation speed is 3000 rpm, the current is adjusted, causing abnormal noise of the electromagnetic clutch, and the abnormal noise is normal. Above 3000 rpm, the clutch is fully engaged and the abnormal sound disappears.

How does V6 3.0T determine the failure of MPI and FSI injectors?

Failure phenomenon:

V6 3.0T EVO engine speed jitter


The fault can be reproduced. The event memory of the engine control unit is read. The cylinder has a misfire record. After replacing the 2 cylinders and other cylinder spark plugs and ignition coils, the 2 cylinder misfire fault is not eliminated. The 2 cylinder spark plug and the ignition coil are not transferred after the fault. . Suspected that the injector is malfunctioning.

Issues that need to be explicitly considered (small tips)

Because some models of this engine are equipped with MPI and FSI fuel injection systems at the same time, the problem is – how to determine whether the FSI system injector or the MPI system injector is faulty without disassembling?

Meet the 3.0T engine dual fuel injection model

(1) EVO engine is dual injection of FSI and MPI;

(2) In the ODIS inspection plan – the “fire-fighting identification FSI/MPI related to the operation mode” is added to the inspection plan;

V6 3.0T EVO vacuum system

V6 3.0T EVO vacuum system

When repairing such a fault in the engine, be sure to find out where the 1/2/3/4 pipelines are connected separately, and check the system seal-ability with a vacuum pump. If this step is omitted, the probability of repairing the car will be reduced by 50%.

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