Computer Relearn Procedures: Other Volkswagen Passat B5 facelift

BODY CONTROLS

Vehicles equipped with body, air conditioning, anti-lock brake or memory computers may require a computer relearn procedure after components are replaced or the vehicle battery is disconnected. Vehicle computers memorize and store vehicle information and operation selections. When the vehicle battery is disconnected, vehicle computer memory may be lost, requiring relearning or resetting. Depending on the vehicle and how it is equipped, the following memories may exist

1. Seat position.
2. Tilt/telescoping steering wheel position.
3. Mirror position.
4. Radio presets and anti-theft code.
5. Clock.
6. Remote keyless entry custom features.
7. Door key lock entry custom features.
8. Power window or sunroof operation.

These do not affect vehicle operation. For systems that do not affect operation, see appropriate article for relearn procedures. Other computer relearn procedures are required for vehicle or system operation. These may include

1. Initial control unit programming.
2. Traction control yaw sensor initializing.
3. Multiplex communication.
4. Anti-theft system or engine immobilizer system passwords.

ENGINE CONTROLS

Vehicles equipped with powertrain control computers may require a computer relearn procedure after the vehicle battery is disconnected. Vehicle computers memorize and store vehicle operation patterns for optimum driveability and performance. When the vehicle battery is disconnected, this memory is lost, which may result in a driveability problem. Depending on the vehicle and how it is equipped, the following driveability problems may exist

1. Rough or unstable idle.
2. Hesitation or stumble.
3. Rich or lean running.
4. Poor fuel mileage.
5. Harsh or poor transmission/transaxle shift quality.

Default data is used until NEW data from each key start is stored. As the computer restores its memory from each new key start, driveability is restored.

Driveability problems may occur during the computer relearn stage. To accelerate computer relearn process after battery removal and installation, specified computer relearn procedures should be performed.

ENGINE CONTROL MODULE PROGRAMMING

Note. While limited diagnostic information is available, vehicle manufacturer does not support diagnostic information using aftermarket scan tools. To properly diagnose vehicle, it is recommended to use VAS 5051 scan tool with VAS 5051/1 adapter cable or VAG 1551 scan tool with 1551/3A adapter cable and VAG 1598/31 test box.

Note. If Engine Control Module (ECM) memory is cleared, ECM is disconnected or loses battery voltage, it is necessary to generate a ECM readiness code. See READINESS CODE .

BEFORE REPLACING ENGINE CONTROL MODULE

Before ECM is replaced on any model perform following procedure.

1. Turn ignition off. Connect Scan Tool (VAG 1551/1552) using Adapter cable (VAG 1551/3) to Data Link Connector (DLC).
2. Turn ignition on. Prior to removing original ECM, print out ECM identification. On scan tool, press 0 and 1 buttons to select ADDRESS WORD 01: ENGINE ELECTRONICS. Print out ECM identification by pressing PRINT button. Press right arrow button. On scan tool, press 0 and 6 buttons to select FUNCTION 06: END OUTPUT. Press "Q" button to enter input. Turn ignition off.

ENGINE CONTROL MODULE CODING

If Engine Control Module (ECM) is replaced, it is necessary to code new ECM. If new ECM is not properly coded, the following problems may occur

1. Driveability problems (e.g., harsh shifting).
2. False malfunctions stored in ECM memory.
3. Increased fuel consumption.
4. Increased exhaust emissions.
5. Reduction in transmission life.
6. All ECM functions are not carried out (e.g., EVAP system operation).
7. On front wheel drive vehicles Anti-Slip Regulation (ASR), ASR warning lamp comes on.

Note. Once procedure is started DO NOT turn ignition off during ECM programming. After coding ECM and starting engine for first time, allow engine to idle for several minutes so ECM can go through learn function. Idle speed may be erratic while ECM is learning.

1. Remove original ECM and install new ECM. Turn ignition on.
2. On scan tool, press 0 and 1 buttons to select ADDRESS WORD 01: ENGINE ELECTRONICS. Press right arrow button. Press 0 and 7 buttons to select FUNCTION 07: CODE CONTROL MODULE. Press "Q" button to enter input. Enter appropriate code for vehicle. See appropriate ENGINE CONTROL MODULE CODING TABLE or VARIATION TABLE as follows.
3. After coding ECM, press 0 and 6 buttons to select FUNCTION 06: END OUTPUT. Press "Q" button to enter input.

After Installing & Coding ECM

After installing and/or coding ECM perform following procedures

1. Use scan tool to check DTC memory, erase if necessary. See RETRIEVING DIAGNOSTIC TROUBLE CODES in appropriate SELF-DIAGNOSTICS article.
2. Perform adaptation of throttle valve control module. See ADAPTATION OF THROTTLE VALVE CONTROL MODULE in appropriate SELF-DIAGNOSTICS article.
3. On vehicles equipped with cruise control, activate cruise control to ECM. See CRUISE CONTROL SYSTEMS article in ACCESSORIES & EQUIPMENT.
4. On vehicles equipped with automatic transmission, perform adaptation of kickdown switch or automatic transmission basic setting. See ADAPTATION OF KICKDOWN FUNCTION or AUTOMATIC TRANSMISSION BASIC SETTING PROCEDURE in appropriate SELF-DIAGNOSTICS article.
5. On vehicles equipped with factory alarm system, perform adaptation of immobilizer to ECM. See appropriate ANTI-THEFT & POWER DOOR LOCKS article in ACCESSORIES & EQUIPMENT.
6. Using scan tool, generate a ECM readiness code. See «READINESS CODE»(ref-158398-S38891365482003092400000) .

ENGINE CONTROL MODULE CODING OPTIONS (1.8L TURBO)

Note. These options relate to Golf, Jetta, Beetle and Passat models equipped with 1.8L engine.

ENGINE CONTROL MODULE CODING VARIATION OPTIONS (BEETLE)

ENGINE CONTROL MODULE CODING OPTIONS (GTI & JETTA)

ENGINE CONTROL MODULE CODING OPTIONS (PASSAT)

ENGINE CONTROL MODULE CODING OPTIONS (1.9L DIESEL)

Note. This procedure relates to GTI, Jetta, and Beetle models equipped with 1.9L diesel engine.

ENGINE CONTROL MODULE CODING VARIATION OPTIONS (1.9L)

ENGINE CONTROL MODULE CODING OPTIONS (2.0L)

Note. This procedure relates to Cabrio, Golf, GTI, Jetta, Beetle and Passat models equipped with 2.0L engine.

ENGINE CONTROL MODULE CODING VARIATION OPTIONS (2.0L)

ENGINE CONTROL MODULE CODING OPTIONS (2.8L)

Note. This procedure relates to EuroVan, Jetta, and Passat models equipped with 2.8L engine.

For Passat 2.8L with engine code ATQ (Scheme 1) For EuroVan 2.8L with engine code AXK (Scheme 2) For Jetta with engine code AFP, see ENGINE CONTROL MODULE CODING VARIANTS (2.8L W/ENGINE CODE AFP) table.

ENGINE CONTROL MODULE CODING VARIANTS (2.8L W/ENGINE CODE AFP)

Scheme 1

Scheme 2

READINESS CODE

Note. Throttle Valve Control Module (TVCM) (J338) adaptation is part of Readiness Code procedures. TVCM adaptation can also be performed by itself, see THROTTLE VALVE CONTROL MODULE in appropriate SELF-DIAGNOSTICS article. For further information, see SELF-DIAGNOSTIC SYSTEMS in appropriate SELF-DIAGNOSTICS article.

READING READINESS CODE

Readiness code is returned to 0 1 1 0 1 1 0 1 if DTC memory is erased, voltage supply to ECM is lost, or a new ECM is installed. To read readiness code, connect scan tool to DLC. DLC is located left side of steering column. Turn ignition on. Follow scan tool manufacturer's instructions and read Readiness Code. (Scheme 3) Readiness code should display 0 0 0 0 0 0 0 0. If readiness code displays as specified, testing is complete. If readiness code does not display as specified, generate readiness code. See GENERATING READINESS CODE.

GENERATING READINESS CODE

Note. Before generating readiness code, perform a long road test. Coolant temperature needs to be greater than 176°F (80°C). Idle, partial throttle, full throttle and overdrive operating conditions must be attained several times. During test drive, apply full throttle until engine speed exceeds 3500 RPM. Read readiness code. OBD system checks components and generates Readiness Code at regular intervals during normal driving.

Note. During readiness code generating procedure, if test result is indicated as OK after selecting a display group, testing has already been carried out and it is okay to proceed to next work step.

1. To generate readiness code, vehicle must be stationary, transmission in Park or Neutral, all electrical consumers off, A/C switched off and coolant temperature at least 176°F (80°C). If possible it is best to warm-up vehicle by test driving. Connect scan tool to DLC. DLC is located at left side of steering column.
2. Using scan tool, retrieve DTCs. See RETRIEVING CODES in appropriate SELF-DIAGNOSTICS article. If DTCs are stored. Perform appropriate test and repair as necessary. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION in appropriate SELF-DIAGNOSTICS article. Using scan tool, clear DTC memory. See CLEARING CODES in appropriate SELF-DIAGNOSTICS article.
3. After clearing DTC memory. Follow scan tool instructions to complete generating readiness code. During test sequence if test is successful scan tool changes display digits from 1 to 0. (Scheme 3) Readiness code should display 0 0 0 0 0 0 0 0. If readiness code displays as specified, testing is complete.

Scheme 3