About Trouble Codes

Diagnostic Trouble Code (DTC) table


NOTE:
- All the DTCs recognized by A/C control head -E87- and displayed on VAG1551 Scan Tool
- If malfunctions occur only occasionally or if the DTC memory was not erased after repairs, these DTCs are displayed as "sporadic." (The contents of DTC memory are retained until erased "permanent memory").
- DTCs and blink codes (only in the case of individual components) appear only in the printout in operating mode -1- "Rapid data transfer".

Example:

DTC Blink code
5-digit 4-digit
00532 2232

- The malfunction type may also appear additionally in the DTC table (a readout marked with a * appears in addition to the relevant component or to the "Info" display).
- After performing repairs, the DTCs should always be checked again and erased with VAG1551 Scan Tool.
- Before replacing components, always test the relevant positive and Ground connections (terminals 75, 30 and 31) as well as all harness connectors (between -E87- and the component recognized as faulty) according to the wiring diagram.
- When dealing with any sporadic DTCs, always pay attention to possible loose terminals in harness connectors.
- After replacing a component of the heating, A/C system, always perform basic setting (function 04) and then check and erase the DTC memory (function 02 and 05).
- Use VAG1598/19 test box to test the electrical connections of the A/C control head -E87- according to the wiring diagram.
- If the A/C control head -E87- remains in operation after switching ignition off, test the wiring to -E87- (connector -E-, terminal -7-) for short circuit to positive according to the wiring diagram.
- If 22 °C (72 °F) is always displayed after switching ignition off and on, regardless of the last setting, check voltage supply (terminal 30) to the A/C control head -E87- according to the wiring diagram.
- The temperature readout can be switched from °C (Celsius) to °F (Fahrenheit) and back by pressing the left temperature "+" button (driver side) when the recirculating air button is pressed.
- If no DTC is detected although complaints have been received regarding the heating, A/C electronics, perform the function 03 "Output Diagnostic Test Mode" and function 08 "Read Measuring Value Block."
- Checking A/C system cooling performance A/C System Cooling Performance, Testing
- For vehicles with Nippondenso compressor there is no A/C compressor speed sensor -G111- installed. If the A/C control head -E87- is improperly coded, the compressor will run for a short time and shut off, since there is no compressor RPM signal.

Up To M.Y. 2000:
- The DTC "Sensor for air quality -G238-" has been introduced for model year 1998.
- With the introduction of sensor for air quality -G238-, A/C control head -E87- was revised (Part No. beginning at index "J").
- Pressure switches -F73- ,-F23- and -F118- have been deleted for model years 1998 on.
- A/C pressure switch -F129- is new for model years 1998 on.

A/C pressure switch -F129- consists of 2 shift elements:
- The compressor shuts off at low or high pressure in the refrigerant circuit via contacts 1 and 2 (switch open).
- The coolant fan is switched into the 2nd stage via contacts 3 and 4 (switch closed).
- If pressure switch -F129- is open between terminals 1 and 2, it is recognized by A/C control head -E87- as excess pressure in the refrigerant circuit and stored as a DTC. If the measured outside temperature is between 0 °C (32 °F) and 50 °C (122 °F), and the switch remains open for more than 30 seconds it switches from excess pressure to low pressure (low pressure switch function) See Read Measuring Value Block, Reading (display group 001, compressor cut-off conditions).
- If while driving an open high pressure switch -F129- was recognized 30 times, e.g. due to a loose connection, the compressor is shut off ("ECON" operating mode). By pressing the "Compressor on" button, or by switching the ignition on and off the compressor can be switched on again. If this malfunction occurs over several drive cycles, the compressor can be switched on again after the DTC memory is erased.