Tests W/codes Audi 90 B3

INTRODUCTION

If no faults were found while performing BASIC TESTING , proceed with tests in this G - TESTS W/ CODES article. If no fault codes or only pass codes are present, proceed to TESTS W/O CODES article for diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.).

"HARD FAILURES"

Hard failures cause "malfunction" light to illuminate and remain on until the malfunction is repaired. If light comes on and remains on (light may flash) during vehicle operation, cause of malfunction must be determined using diagnostic (code) charts. If a sensor fails, control unit will use a substitute value in its calculations to continue engine operation. In this condition, vehicle is functional, but loss of good driveability will most likely be encountered.

"INTERMITTENT FAILURES"

Intermittent failures may cause "malfunction" light to flicker or illuminate and go out after the intermittent fault goes away. The corresponding trouble code, however, will be retained in control unit memory. If related fault does not reoccur within a certain time frame, related trouble code will be erased from control unit memory. Intermittent failures may be caused by sensor, connector or wiring related problems. See INTERMITTENTS in TESTS W/O CODES article.

CIS DIGITAL CONTROL (200/200 QUATTRO)

Turn ignition on. Engine warning light (on instrument panel) should come on. Start engine. Engine warning light should go off. Drive vehicle for at least 5 minutes to store necessary information in control unit memory. During test drive, accelerate engine above 3000 RPM and briefly accelerate using full throttle. DO NOT turn ignition off as this will erase control unit memory. If engine will not start, crank starter for at least 5 seconds. Return ignition key to "ON" position. Fault codes may now be read.

CIS-E III (90, 80/90 QUATTRO & 100/100 QUATTRO)

Drive vehicle for a minimum of 5 minutes to allow fault information to be stored. If a no-start condition exists, operate starter for at least 6 seconds. DO NOT turn ignition off. This will erase the fault memory.

CIS MOTRONIC (80)

Drive vehicle for a minimum of 5 minutes to allow fault information to be stored. When ECU detects a temporary fault, the "CHECK" light on the instrument panel will flash. The light will continue to flash until ignition is turned off. The ECU may clear the fault on next engine start, and the "CHECK" light will not flash unless fault is detected again. Vehicle will have to be test driven for at least 5 minutes to reset fault. When ECU detects a permanent fault, "CHECK" light will flash but fault will remain in ECU memory until physically erased.

Scheme 17

1. Locate 2 diagnostic connectors in drivers footwell area. Connect a test light between connectors A and B. (Scheme 17)
2. Connect a jumper wire to other terminal in connector A. Touch other end of jumper wire to the only terminal in connector B for at least 4 seconds. Fault codes will now be displayed by the flashing "CHECK" light for California vehicles or a flashing test light for Federal vehicles. NOTE: Careful attention must be paid to flashing light, since there are no discernable break points between 4-digit number groups.
3. Trouble codes will then be flashed as 4 digit numbers. After each flash there will be a 1/2 second pause before the next flash occurs. Adding flashes together will obtain each code digit.
4. To advance to next fault code, touch end of jumper wire to the only terminal in connector B for at least 4 seconds. (Scheme 17) After each digit code is flashed, there will be a 2 1/2 second pause. After fourth digit of number is flashed, a 2 1/2 second pause will follow before the fault code is repeated.
5. The fault code will be repeated until the ignition is turned off. Record fault code. Check the list of input codes and possible problems. See CIS DIGITAL CONTROL INPUT FAULT CODE IDENTIFICATION CHART.
6. Check and repair circuits and/or sensors as indicated. After the fault is corrected, repeat step 1) and check for additional codes.

OUTPUT CODES

1. Control unit circuitry allows checking of certain components by generating specific output signals. During output diagnosis, components can be checked by listening for their operation. Diagnostic output code will flash during testing, indicating which step control unit is in.
2. Turn ignition switch off to erase fault memory. Turn ignition on. DO NOT crank or start engine. If this is done, system will automatically switch to input testing when diagnostic procedure has been activated.
3. To activate diagnostic procedure, locate 2 diagnostic connectors in drivers footwell area. Connect a test light between connectors A and B. (Scheme 17)
4. Connect a jumper wire to other terminal in connector A. Touch other end of jumper wire to the only terminal in connector B for at least 4 seconds.
5. This will activate the first of 5 output steps. To proceed to the next step, touch end of jumper wire to the only terminal in connector B for at least 4 seconds. (Scheme 17)
6. First step (Code 4433) will activate fuel pump. Pump will continute to activate throughout all 5 steps and until diagnostic procedure is ended by turning off ignition.
7. Second step (Code 4441) will operate OXS frequency valve at 50 percent duty cycle until next step is activated.
8. Third step (Code 4442) will cause wastegate frequency valve to switch on and off until next step is activated.
9. Fourth step (Code 4443) will cause cold start valve to switch on and off for about 10 seconds.
10. Fifth step (Code 4343) causes carbon canister shut-off valve to switch on and off until step is terminated by turning ignition switch off. If necessary, output tests may be continued by repeating steps 3) through 10).
11. If any device does not operate as indicated during output tests, see appropriate test in the SYSTEM/COMPONENT TESTS article.

CIS DIGITAL CONTROL INPUT FAULT CODE IDENTIFICATION CHART

1. Locate 2 diagnostic connectors in drivers footwell area. Connect a test light between connectors A and B. (Scheme 17) NOTE: If ICU is replaced, check ignition timing. If warning light blinks while driving, knock regulation is at maximum control limit.
2. Connect a jumper wire to other terminal in connector A. Touch other end of jumper wire to the only terminal in connector B for at least 4 seconds. Fault codes will now be displayed by the flashing "CHECK" light for California vehicles or a flashing test light for Federal vehicles. These fault codes will be from the Ignition Control Unit (ICU). NOTE: Careful attention must be paid to flashing light, since there are no discernable break points between 4-digit number groups.
3. Trouble codes will then be flashed as 4 digit numbers. After each flash there will be a 1/2 second pause before the next flash occurs. Adding flashes together will obtain each code digit.
4. To advance to next fault code, touch end of jumper wire to the only terminal in connector B for at least 4 seconds. (Scheme 17) After each digit code is flashed, there will be a 2 1/2 second pause.
5. After fourth digit of number is flashed, a 2 1/2 second pause will follow. Continue displaying codes until Code 0000 is displayed. Code 0000 displays by light remaining on for 2 1/2 seconds, then off for 2 1/2 seconds with no pause in flashing. This indicates that all fault codes from ICU have been displayed.
6. Repeat step 4) after Code 0000 is displayed. This time, however, faults that are displayed will be from Fuel Injection Control Unit (FICU). Engine speed may increase. Record all codes.
7. Repeat step 4) until all FICU fault codes have been displayed. When all fault codes from FICU have been displayed, a Code 0000 will display. For a list of all fault codes, refer to the «CIS-E III FAULT CODE IDENTIFICATION CHART»(/audi/90/b3-1987-1991/remont/testing-diagnostics/#tests-wcodes) table.

CIS-E III FAULT CODE IDENTIFICATION CHART

1. Locate 2 diagnostic connectors in drivers footwell area. Connect a test light between connectors A and B. (Scheme 17)
2. Connect a jumper wire to other terminal in connector A. Touch other end of jumper wire to the only terminal in connector B for at least 4 seconds. Fault codes will now be displayed by the flashing "CHECK" light for California vehicles or a flashing test light for Federal vehicles.
3. Trouble codes will then be flashed as 4 digit numbers. After each flash there will be a 1/2 second pause before the next flash occurs. Adding flashes together will obtain each code digit.
4. To advance to next fault code, touch end of jumper wire to the only terminal in connector B for at least 4 seconds. (Scheme 17) After each digit code is flashed, there will be a 2 1/2 second pause.
5. After fourth digit of number is flashed, a 2 1/2 second pause will follow. Continue displaying codes until Code 0000 is displayed. This indicates that all fault codes have been displayed.
6. Continue with step 4) until a Code 0000 is displayed indicating all fault codes have been displayed. Code 0000 is read when FIL is on for 2.5 seconds, then off 2.5 seconds, and continues this display with no pause in flashing.

Scheme 18

CIS MOTRONIC FAULT CODE IDENTIFICATION CHART

CLEARING CODES

Note. The procedure for erasing trouble codes from memory on CIS-E III equipped Federal vehicles was not available from manufacturer.

To erase fault codes, turn ignition off.

Since procedure for clearing codes is only available for California vehicles, identify vehicles by FICU and ICU part numbers. California vehicles are FICU 443 906 264 B and ICU 443 907 397 E, Federal vehicles are FICU 443906 264 C and ICU 443 907 397 C.

1. To erase trouble codes from memory (Calif. vehicles only), turn ignition off. Insert fuse in top of fuel pump relay. (Scheme 19) Turn ignition on. Wait at least 4 seconds then remove fuse.
2. A signal that repeatedly comes on for 2.5 seconds and then goes off for 2.5 seconds should appear. Reinstall fuse in top of fuel pump relay. Wait at least 10 seconds, then remove fuse. If procedure was followed correctly, warning light will stay on continuously.

Scheme 19

CIS MOTRONIC 80

1. To erase trouble codes from memory (Calif. vehicles only), turn ignition off. Insert fuse in top of fuel pump relay. (Scheme 19) Turn ignition on. Wait at least 4 seconds then remove fuse.
2. A signal that repeatedly comes on for 2.5 seconds and then goes off for 2.5 seconds should appear (Code 0000). Reinstall fuse in top of fuel pump relay. Wait at least 10 seconds, then remove fuse. If procedure was followed correctly, warning light will stay on continuously.

SUMMARY

If no hard fault codes (or only pass codes) are present, proceed to TESTS W/O CODES article diagnosis by symptom (i.e. ROUGH IDLE, NO START, etc.), or intermittent diagnosis procedures.

See also:
• BASIC TESTING
• TESTS W/O CODES
• CIS-E III FAULT CODE IDENTIFICATION CHART