Electrical Troubleshooting Steps (GROUP D2, NO. 91-01)
Publication date: 1991-08-31Reference number: GROUP D2, NO. 91-01
ELECTRICAL TROUBLESHOOTING STEPS
TECHNICAL SERVICE BULLETIN
Reference Number(s): GROUP D2, NO. 91-01
ELECTRICAL TROUBLESHOOTING STEPS
Model(s): 1989-91 Audi 100, 200 w/ NF Engine
Group: D2
Bulletin No.: 91-01
Date: August 31, 1991
CIS-E III FUEL AND IGNITION SYSTEM, ELECTRICAL TESTING
- Perform all measurements using the Fluke 83 multimeter (US 1119) shown in Fig 1 , or equivalent.
- The specified values given in the procedures are valid within a temperature range of 0° and +40°C (32° and 104°F).
- If the measured values deviate from the specified values; check the wiring and connectors before replacing any components.
CAUTION:
Always switch the multimeter to the desired units and range of measurement (Volts, Ohms, etc.) before making any test connections to the system.
- Use the US 1115 LED tester (VAG 1527B) shown in Fig 2 , to indicate voltage presence as indicated in the procedures.
- Always use the VW 1594 adaptor kit shown in Fig 3 , to make connections between the test instruments (Fluke 83 and US 1115 LED tester) and the test point.
- Use Test box VAG 1598 and adaptor wire kit VW 1594 shown in Fig 4 , to make all test connections to the control unit.
CAUTION:
Do not connect or disconnect adaptors/test instruments to the VAG 1598 Test box while the ignition is switched ON.
REQUIREMENTS
- Battery voltage OK
- Fuses OK.
- System grounds OK.
- Power output stage of coil disconnected.
PROCEDURE
- Switch OFF ignition.
- Disconnect CIS-E III fuel injection control unit (J21) harness connector.
- Connect VAG 1598 Test box to control unit harness connector using adaptor cable VAG 1598/3.
- Control unit is not connected.
- Make connections on the VAG 1598 Test box as indicated in the following procedures.
NOTE:
The following checks apply to the (J 21) CIS-E III fuel injection control unit.
FUEL INJECTION CONTROL CHECK
| Test step | VAG 1598 terminals | To be tested | Test conditions and additional steps (if any) | Specified value or result |
|---|---|---|---|---|
| 1 | 14 + 18 | Voltage supply to ECU (J 21) 14 = fuse 28 positive 18 = ground | Switch ON ignition | Approx. battery voltage. If NO: check groundconnection or fuse 28, eliminate open circuit. |
| --- | 18 + 19 Calif. only | 18 = ground 19 = fuse 21 positive | Ignition switched ON | Approx. battery voltage. If NO: check groundconnection or fuse 21, eliminate open circuit. |
| 2 | 33 + 35 | A/C compressor switch ON signal | Ignition switched ON A/C switched ON to AUTO or BI-LEV | Approx. battery voltage. If NO: eliminate open circuit. |
| --- | --- | --- | --- | Switch OFF ignition. Switch multimeter to resistance range. |
| 3 | 7 + 18 | Wire to Oxygen sensor (G 39) | Disconnect Oxygen sensor and connect harness wire to ground with ignition switched OFF. | 0.5 Ohms maximum (continuity). If NO: eliminate open circuit. |
| --- | --- | --- | --- | No testing is performed on terminal 8 for the Oxygen sensor shield. |
| 4 | 4 + 5 | Differential pressure regulator (N 73) | Ignition switched OFF | 17.5 to 21.5 Ohms. If NO: check diff. pressure regulator |
| --- | --- | --- | --- | Switch OFF ignition. Substitute US 1115 LED tester for multimeter. |
| 5 | 14 + 34 | Activation of CIS-E III to manual trans or via auto trans selector lever Auto trans ONLY: | Switch ON ignition Selector on N then P Selector on any other position except N or P | LED tester must light up. If NO: eliminate open circuit. LED tester must light up. LED tester must NOT light up. |
| 6 | 3 + 18 | Coolant temperature sensor (G 62) | Ignition switched OFF | Use chart shown in Fig. Fig 1 to look up value. |
NOTE:
The following electrical checks apply to the (J 154) CIS-E III ignition control unit. - Switch multimeter to 20 Volt range.
NOTE:
Terminals in parentheses are for fuel injection control unit (J 21) harness connector.
IGNITION CONTROL UNIT ELECTRICAL CHECKS
| Test step | VAG 1598 terminals | To be tested | Test conditions and additional steps (if any) | Specified value or result |
|---|---|---|---|---|
| 1 | 6 + 20 | Voltage supply to ignition ECU (J 154) 6 = fuse 27 positive 18 = ground | Switch ON ignition | Approx. battery voltage. If NO: Check groundconnection or fuses27 and 4, eliminate open circuit. |
| 2 | 6 + 22 | Voltage supply to ignition control unit (J 154) 6 = positive from fuse 27 22 = ground | Operate starter briefly | 8 Volts minimum. If NO: eliminate open circuit. |
| 3 | 7 + 20 | Idle switch (F 60) | Throttle valve in idle position with ignition switched ON Operate throttle | Approx. battery voltage. If NO: check throttle valve basic adjustment. 0 Volts If NO: check/adjust idle switch or eliminate open circuit. |
| 4 | 9 + 20 | Full throttle switch (F 81) | Throttle valve in idle position with ignition switched ON Operate full throttle switch | 0 Volts. If NO: check/adjust full throttle switch. Approx. battery voltage. If NO: eliminate open circuit. |
| 5 | 14 + 20 | Wire 14 to fuel pump relay (J 17) | Ignition switched ON | Approx. battery voltage. If NO: eliminate open circuit. |
| 6 | 3 + 6 | Wire 3 to fuel pump relay (J 17) | Ignition switched ON with fuse installed in top of relay | Approx. battery voltage. If NO: eliminate open circuit. |
| --- | --- | --- | --- | Switch OFF ignition. Switch multimeter to resistance range |
| 7 | 16 + 20 | Wiring to power output stage of coil (N 70) | Ignition switched OFF Bridge terminal 2 (green) and terminal 3 (brown/white) | 0.5 Ohms maximum. Check or eliminate open circuit. |
| --- | --- | --- | --- | When checking the wiring between the control unit (J 154) and the fuel pump relay (J 17), Do NOT apply a voltage to any of the respective terminals. |
| 8 | 12 + 13 | Wiring to knock sensor (G 61) | Disconnect knock sensor and bridge all three terminals of harness connector | 0.5 Ohms maximum (continuity) If NO: eliminate open circuit. |
| 9 | 4 + 10 | Wiring to Hall sender (G 40) | Disconnect Hall sender and bridge outer terminals | 0.5 Ohms maximum (continuity). If NO: eliminate open circuit. |
| 10 | 10 + 24 | Wiring to Hall sender (G 40) | Ignition switched OFF Hall sender disconnected Bridge outer terminal (brown/white) with center terminal (green/white) | 0.5 Ohms maximum. If NO: check Hall sender or eliminate open circuit. |
| 11 | 22 + 25 | Coolant temperature sender (G 62) | Ignition switched OFF | Use chart shown in Fig. Fig 1 to look up value. |
| 12 | 2 + (25) 5 + (1) 7 + (28) 8 + (21) 9 + (31) 17 + (30)21 + (26) | Wiring between ignition control unit (J 154) and fuel injection control unit (J 21) | Ignition switched OFF With ignition switched OFF disconnect harness connector from fuel injection control unit. | 0.5 Ohms maximum. If NO: eliminate open circuit. |