Fault codes 18265 found in 2 location

[jackms]

Hello All

I have an ageing 2003 2.5tdi Audi A6.
It recently behaving very strangely.
On my daily commute two work 45 miles 50% A road 50%motorway the car would shudder, similar to wheel loosing grip, ESP light would turn on and water temperature gauge would show 0.
A few minutes later the ESP light would turn off and at the same time the temp gauge would go back to 90.
No other gauge would move.

I have VCDS and when I run a scan the fault code 18265 load signal appears in the location Auto Trans and ABS brakes.

The scan also real a faulty water temperature sender (G2).

Could someone help me decipher the meaning of those codes?

Cheers

Jack

[Crasher]

I reckon my wife was made by Audi, she is getting a bit strange as she ages.....

I have seen this when the blue/black wire from the Df terminal on the back of the alternator is broken or disconnected.

18265 (P1857) - Load Signal: Error Message from ECU

Possible Causes

No/incorrect signal being output by engine control unit
Fault in "Engine actual torque signal" diagnosed by engine control unit
Incorrect or defective engine control unit
Incorrect or defective gearbox control unit

Possible Solutions

Read measured value block; Display Group Numbers 081 and 009
Read out stored engine control unit fault code and eliminate fault
Check identification of engine control unit
Check identification of gearbox control unit

When selecting measured value block, note type of gearbox hydraulic control system.

• ◆ Fault detection conditions: Fault in component concerned is diagnosed by engine control unit. This fault diagnosis is transmitted via CAN bus wire to gearbox control unit.
• ◆ Fault detection condition: No problem detected with engine-speed and throttle-valve signals and no load signal detected for 245 ms.
• ◆ If load signal fault is detected by the engine control unit, this fault is transmitted to the gearbox control unit in the form of a duty cycle fault.

[jackms]

Hi Chrasher

thanks for your message.
What is the "DF terminal"

Jack

[jackms]

"DF" Dynamo field

The question is can it be sorted without having to remove the alternator...

[Crasher]

Possibly, you have to look at the back of it and see if the wire is plugged in, if it is you have to disconnect it and measure its overall resistance back into the car.

[jackms]

Do you have some value of the resistance I should find?
Where would so two wires go into the car?

Jack

[Crasher]

The resistance end to end should be as close to zero as possible. I could do with your engine type code and vehicle type number for the wiring specifics.

[jackms]

I am unsure of what you are asking so please find below a link to the log of the scan

Dropbox - Log-WAUZZZ4B34N034775.txt

Jack

[jackms]

I have replaced this afternoon the coolant temperature sensor so hopefully this code is cleared

[Crasher]

So it is a 2004 model year built 29/09/2003 with a BDG engine and a GJT transmission, the vehicle is a type 4B5 0BH.

This is the VAG interpretation of the codes in the transmission ECU.

18265 (P1857) Load signal. Fault message from engine CU

Possible cause of trouble
Engine control unit detects “engine actual torque” fault
Incorrect or defective engine control unit
Mechanical fault in engine

Remedy
Interrogate engine control unit fault memory and eliminate fault
Check engine control unit identification; interrogate fault memory and eliminate fault

Explanatory notes
The “engine actual torque” signal is transmitted from the engine control unit to the automatic gearbox control unit -J217-.
Information is exchanged between the control units by way of the CAN bus

This is the VAG interpretation of the same code in the ABS ECU

18265 Load signal - fault message from engine control unit- This fault can only occur on vehicles with TCS

Possible causes of fault
Data transfer through the engine control unit takes place via CAN bus. A fault has been stored in the engine control unit.

Fault remedy
For more information, please refer to "Function of Bosch ABS/EDL 5.3"
Eliminate the fault in the engine management system in line with the appropriate engine Workshop Manual and delete the fault memory of the engine control unit

It is possible that changing the temperature sender will solve the issue.

Function of Bosch ABS/EDL/TCS 5.3 Series

The Bosch type 5.3 system has a more compact design. The hydraulic pump -V39, the hydraulic unit -N55 and the control unit -J104 are combined to form the hydraulic control unit. The bolts that connect the individual components of the hydraulic unit must not be slackened. The direct connection between these components reduces possible sources of faults. There is no provision for repairing the hydraulic control unit - it must be renewed if faulty. The brake system is split diagonally into two. One actuating the front left and rear right brakes and one actuating the front right and rear left brakes. The components of the Bosch type 5.3 system have the following functions:

Electronic brake pressure distribution

The control unit -J 104 is programmed with specially designed software for electronic brake pressure distribution which assumes the function of the brake pressure regulator. In the event of failure of the ABS, the signal which actuates the ABS/EDL warning lamp and the red brake fault symbol is sent to the dash panel insert via the wire from contact 21 of control unit -J104. No signal and signal present conditions are distinguished in the dash panel insert up to production week 20/1997. The ABS/EDL warning lamp will light up and the red brake fault symbol will normally light up in addition. In vehicles from production week 21/1997 onwards, the red brake fault symbol no longer illuminates at all times when a failure of the ABS has occurred. In cases where a failure of the ABS has occurred, but the electronic brake pressure distribution function can still be maintained by a back-up feature, the signal sent to the dash panel insert is pulsed. The dash panel insert distinguishes between three conditions: no signal present, pulsed signal, and continuous signal present. The ABS/EDL warning lamp and the red brake fault symbol light up in accordance with the signal received.



1 - Terminal 15
2 - Signal for actuation of ABS/EDL warning lamp and red brake fault symbol.
3 - Voltage supply for the ABS/EDL warning lamp.
4 - Voltage supply for red brake fault symbol.
A - During a phase "A" (after ignition is switched on) ABS/EDL warning lamp is actuated for two seconds during self-test by means of signal "2" and comes on. During this phase, an internal function in the dash panel insert suppresses the activation of the red brake fault symbol.
B - Signal "2" is not present during phase "B". The ABS/EDL warning lamp and red brake fault symbol do not light up.
C - In phase "C" self-diagnosis has detected a fault, which does not cause electronic brake pressure distribution function to be deactivated. Signal "2" is pulsed. Only the ABS/EDL warning lamps illuminates
D - In phase "D" self-diagnosis has detected a fault, which causes electronic brake pressure distribution function to be deactivated. Signal "2" is present continuously. Both the ABS/EDL warning lamp and the red brake fault symbol light up.

If the red brake fault symbol illuminates, this indicates that the electronic brake pressure distribution function has failed. Extra care must be taken if the vehicle has to be driven in this condition.

ABS:

The anti-lock brake system (ABS) prevents the wheels from locking when the brakes are applied by the driver.

EDL:

The electronic differential lock (EDL) is an aid when driving away from a standstill. An electronically controlled brake application on the spinning driven wheel provides a torque reaction point for the differential. This enables the wheel with better traction to make use of the engine power. This also applies when reversing.
EDL is standard equipment on vehicles with 4WD. While EDL acts on all four wheels in vehicle with 4WD on vehicles with FWD it acts only on the front wheels. A mechanical differential lock is not required. The EDL control function can be initiated at road speeds up to 40 km/h. Once EDL has been activated, it cuts out automatically at a predetermined upper speed threshold of 40 km/h on vehicles with FWD and 80 km/h on vehicles with four wheel drive. Suction dampers are fitted in the hydraulic unit. They assist the build-up of pressure in the corresponding wheel brake cylinders when EDL is active. The operating range of the pressure-limiting valve in the hydraulic unit is 170 ± 25 bar. To stop the brakes overheating, the EDL control function is suppressed if the temperature of the brakes exceeds a certain value. The temperature value is defined in control unit-J104. The temperature of the brakes is calculated by the control unit using a simulation formula. The EDL is then reactivated if the calculated temperature drops below a predetermined lower threshold. The operation of the brake system and the ABS function are not affected by this automatic cut-off feature. When the ignition is switched off, the calculated temperature of the hot brakes is stored in the memory until the ignition is switched on again. When the ignition is switched on, the dash panel insert sends a time signal which enables the control unit -J104 to calculate the period the vehicle has been left standing. This period is put into the temperature simulation formula to calculate the new temperature of the brakes. If the vehicle has been left standing for more than one hour, the control unit will automatically assume a brake temperature equal to the lowest value in the simulation formula. If EDL is deactivated on account of the temperature limit being exceeded this is indicated in the measured value block for a period of 20 ignition cycles.

TCS:

TCS (traction control system) is fitted only on vehicles with front-wheel drive: In these vehicles, observe control unit encoding. The traction control function requires an exchange of signals between control unit -J104, the engine control unit and the gearbox control unit. The control units communicated with each other. Two communications systems are in use: ‒

Data transfer takes place on several individual wires.

Data are transferred by way of the CAN bus. The CAN bus employs only two wires, these are capable of transmitting all the necessary data.
To find out which communications system is being used for data transfer, check the control unit version. The TCS traction control system prevents the driven wheels from spinning under acceleration: The system operates by reducing engine torque and is active at all speeds. The EDL and TCS functions act together to assist acceleration. Depending on the engine version, the TCS also incorporates an overrun torque limiting function (MSR). MSR prevents the driven wheels from locking up due to excessive engine braking torque, for instance when the driver changes down from 3rd to 2nd gear. The engine braking effect is reduced via the idle volume control. If required, the TCS function can be switched off (and on again) by means of the TCS switch in the centre console. The TCS switch has no influence on MSR. The TCS will be reactivated automatically the next time the ignition is switched on. When the system is deactivated, the TCS warning lamp illuminates in the dash panel insert. The warning lamp flashes at rate of three times per second when the control function starts working.