Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1994 Audi 90 CS QuattroFACTORY OEM SERVICE PROCEDURE
Trouble Code Identification
TROUBLE CODE IDENTIFICATION
| DTC Code ( Blink Code) (1) | Affected Sensor/Circuit | ||||||
|---|---|---|---|---|---|---|---|
| 00000 (4444) | No Fault Recognized | ||||||
| 00281 (1231) | Vehicle Speed Sensor (VSS) | ||||||
| 00513 (2111) | Engine Speed (RPM) Sensor | ||||||
| 00514 (2112) | Crankshaft Position (CKP) Sensor | ||||||
| 00515 (2113) | Camshaft Position (CMP) Sensor | ||||||
| 00516 (2121) | Closed Throttle Position (CTP) Switch | ||||||
| 00518 (2212) | Throttle Position (TP) Sensor | ||||||
| 00521 (2242) (2) | CO Fuel Trim Potentiometer | ||||||
| 00522 (2312) | Engine Coolant Temperature (ECT) Sensor | ||||||
| 00524 (2142) | Right Knock Sensor I | ||||||
| 00525 (2342) | Right Oxygen Sensor (O2S) | ||||||
| 00531 (2231) | Mass Airflow (MAF) Sensor | ||||||
| 00532 (2234) | Supply Voltage | ||||||
| 00535 (2141) (2) | Knock Sensor I Control | ||||||
| 00536 (2143) (2) | Knock Sensor II Control | ||||||
| 00537 (2341) | Right Oxygen Sensor (O2S) Control | ||||||
| 00540 (2144) | Knock Sensor II (Left) | ||||||
| 00553 (2324) | Mass Airflow (MAF) Sensor | ||||||
| 00554 (2331) | Left Oxygen Sensor (O2S) Control | ||||||
| 00555 (2332) | Left Oxygen Sensor (O2S) | ||||||
| 00560 (2411) | EGR System | ||||||
| 00577 (2141) | Knock Regulation - Cyl. 1 | ||||||
| 00578 (2141) | Knock Regulation - Cyl. 2 | ||||||
| 00579 (2141) (3) | Knock Regulation - Cyl. 3 | ||||||
| 00580 (2143) | Knock Regulation - Cyl. 4 | ||||||
| 00581 (2143) | Knock Regulation - Cyl. 5 | ||||||
| 00582 (2143) (3) | Knock Regulation - Cyl. 6 | ||||||
| 00585 (2411) | EGR Temperature Sensor | ||||||
| 00609 (4332) | Ignition Power Output Stage 1 | ||||||
| 00610 (4332) | Ignition Power Output Stage 2 | ||||||
| 00611 (4332) | Ignition Power Output Stage 3 | ||||||
| 00689 (4431) (3) | Leak In Intake Air System | ||||||
| 01242 (4332) | Final Stages Of Control | ||||||
| " | (Ignition Power Output Stage) | ||||||
| 01243 (4333) (3) | Intake Manifold Change-Over Valve | ||||||
| 01247 (4343) | EVAP Control Solenoid Valve | ||||||
| 01249 (4411) | Fuel Injector Cyl. No. 1 | ||||||
| 01250 (4412) | Fuel Injector Cyl. No. 2 | ||||||
| 01251 (4413) | Fuel Injector Cyl. No. 3 | ||||||
| 01252 (4414) | Fuel Injector Cyl. No. 4 | ||||||
| 01253 (4415 Or 4421) | Fuel Injector Cyl. No. 5 | ||||||
| 01254 (4416 Or 4422) | Fuel Injector Cyl. No. 6 | ||||||
| 01257 (4431) | Idle Air Control (IAC) Valve | ||||||
| 01265 (4312) | EGR Control Solenoid Valve | ||||||
| 65535 (1111) | ECM Malfunction | ||||||
|
|||||||
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.