2021-2024 Audi Cooling Fan Control DTC P048000 P048100

Symptoms

Owners of certain 2021-2024 Audi models may notice specific warning signs related to their cooling system. These include the customer complaint that "the exhaust emissions warning lamp lights up, or the warning lamp for coolant temperature/ low coolant level lights up." Additionally, the "Fan runs continuously," which workshop findings confirm as the fan(s) running "constantly."

Fault Codes / DTCs

When these symptoms occur, the Engine Control Unit -J623- (address word 0001) is likely to log specific Diagnostic Trouble Codes (DTCs). These codes indicate an issue with the radiator fan control system:

Code	Description	Module
P048000	Cooling Fan 1 Control Circuit	Engine Control Unit -J623-
P048100	Cooling Fan 2 Control Circuit	Engine Control Unit -J623-

Diagnosis and Technical Background

Audi Technical Service Bulletin 2075348/1 explains that in very rare cases, an open circuit in the wiring may occur. This electrical fault can cause the radiator fan to be incorrectly identified as a component potentially causing damage, leading to its continuous operation and the logging of DTCs like P048000.

To diagnose this issue, technicians will first confirm the workshop findings of a constantly running fan. They will then check for the presence of DTCs P048000 or P048100 in the Engine Control Unit -J623-.

Repair Procedure Summary

Addressing the radiator fan control P048000 issue involves a series of diagnostic and repair steps outlined in TSB 2075348/1:

1. Ignition Activation: The technician will switch on the ignition to ensure the main relay is activated.
2. Fan Connector Check: The connector to the fan will be unplugged.
3. Voltage Supply Test: The voltage supply on control wire 87 will be checked while it is under load. If this test is successful, the ignition can be switched off.
4. PWM Wire Inspection: The PWM (Pulse Width Modulation) wire will be checked for an open circuit. This inspection focuses on the section between the engine control unit connector and the fan connector.
5. Guided Fault Finding: If both the voltage supply and PWM wire checks are satisfactory, the technician will proceed with Guided Fault Finding to further pinpoint the root cause.

Warranty Information

This Technical Service Bulletin provides specific guidelines for warranty claims related to the radiator fan control P048000 and P048100 DTCs. The Service Number for this issue is 9713, with a Damage Code of 0015. Labor operations include checking the electric fan (code 1908 0199), checking the engine wiring harness (code 9713 0199 if required), and repairing the wiring harness (code 9709 41xx). Guided Fault Finding (GFF) has a labor operation code of 0150 0060. All claims must adhere to the Audi Warranty Policies and Procedures Manual. The claim comment references TSB 2075343/1.

Important Warning: If the vehicle is outside of any warranty, this Technical Service Bulletin is for informational purposes only. This means that repairs for this specific issue may not be covered by Audi.

Owner Action

If your 2021-2024 Audi is exhibiting symptoms such as a constantly running radiator fan, or if you see an "exhaust emissions warning lamp lights up" or "warning lamp for coolant temperature/ low coolant level lights up" message, it is recommended to have your vehicle inspected by an authorized Audi service center. They can diagnose the underlying cause, check for DTCs like P048000, and perform the necessary repairs according to Technical Service Bulletin 2075348/1.

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Source: NHTSA ID 10255301