Engine Controls - System & Component Testing: Introduction
Before testing separate components or systems, perform a visual inspection. See VISUAL INSPECTION . Since many computer-controlled and monitored components set a trouble code if they malfunction, also perform procedures in appropriate SELF-DIAGNOSTICS article.
NOTE:
Testing individual components does not isolate shorts or opens. Perform all resistance tests with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use DVOM to isolate wiring harness open or short circuits.
NOTE:
Manufacturer recommends using Scan Tool VAG 1551, VAG1552, VAS 5051 or VAS5052 and Test Box VAG 1598. Generic scan tools may not be able to perform all functions that are necessary (e.g. Readiness Code, Idle Check and Automatic Test Sequence etc.).
NOTE:
For testing most engine systems and components Volkswagen recommends using a scan tool. When voltage supply to ECM (J220) is interrupted or ECM (J220) memory is erased, ECM (J220) looses all "learned" and/or "basic" values. Serious driveability problems may occur depending on vehicle mileage. A relearn procedure must be performed. See TEST DRIVE RELEARN PROCEDURE
.
NOTE:
Manufacturer's alpha-numeric component designations are used throughout this article. For component alpha-numeric identification, see MANUFACTURER'S COMPONENT ALPHA-NUMERIC IDENTIFICATION
table. Manufacturer's alpha-numeric component designations are also used by some scan tool manufacturer's. Alpha-numeric identification in MANUFACTURER'S COMPONENT ALPHA-NUMERIC IDENTIFICATION
table is only a partial list. These are components pertaining to engine performance.
MANUFACTURER'S COMPONENT ALPHA-NUMERIC IDENTIFICATION
| Component | Alpha-Numeric Identification |
|---|---|
| ABS Control Module | J104 |
| ABS Warning Light | K47 |
| Accelerator Position Sensor 1 | G79 |
| Accelerator Position Sensor 2 | G185 |
| Air Bag Control Module | J234 |
| Air Bag Warning Light | K75 |
| AC Control Module | J255 |
| Angle Sensor 1 For Throttle Valve Drive | G187 |
| Angle Sensor 2 For Throttle Valve Drive | G188 |
| Barometric Pressure Sensor (Inside ECM) | G96 |
| Brake Booster Sensor | G294 |
| Brake Light Switch | F |
| Brake Pedal Switch | F47 |
| Brake Vacuum Pump Motor | V192 |
| CAN Data Bus Interface (Gateway) | J533 |
| Camshaft Position Sensor | G40 |
| Charge Air Pressure Sensor | G31 |
| Clutch Pedal Switch | F36 |
| Comfort Systems Central Control Module | J393 |
| ECM | J220 |
| ECM Power Supply Relay | J271 |
| ECT Sensor | G62 |
| Engine Coolant Level Sensor | G32 |
| Engine Speed (RPM) Sensor | G28 |
| EPC Warning Light | K132 |
| EVAP Canister Purge Valve | N80 |
| EVAP Leak Detection Pump | V144 |
| Fuel Pump | G6 |
| Fuel Pump Relay | J17 |
| HO2S Upstream TWC | G39 |
| HO2S Downstream TWC | G130 |
| IAT Sensor | G42 |
| Ignition Coil With Power Output Stage | N70, N127, N129 & N292 |
| Immobilizer Induction Coil | D2 |
| Immobilizer Warning Light | K117 |
| Injectors | N30-N33 |
| Instrument Cluster Control Module (Also Used By Immobilizer) | J285 |
| Knock Sensor 1 | G61 |
| Knock Sensor 2 | G66 |
| MAF Sensor | G70 |
| Malfunction Indicator Light | K83 |
| Oil Level Sensor | G266 |
| Oil Pressure Switch | F1 |
| Oil Pressure Warning Light | K3 |
| Power Steering Switch | F88 |
| Recirculating Valve For Turbocharger | N249 |
| Secondary Air Injection Valve | N112 |
| Secondary Air Injection Pump Motor | V101 |
| Secondary Air Injection Pump Relay | J299 |
| Steering Control Module | J453 |
| Steering Sensor | G85 |
| Throttle Position Actuator | V60 |
| Throttle Valve Control Module | J338 |
| Throttle Valve Drive | G186 |
| Transmission Control Module (Automatic Transmission) | J217 |
| Valve For Camshaft Adjustment | N205 |
| Vehicle Speed Sensor (Speedometer) | G22 |
| Wastegate By-Pass Regulator Valve | N75 |