Home ReviewsRefund
Home/Audi/5000 S/Audi 5000 S (1985-1988)/Repair manual/Ignition System/Ignition System - Hall Effect
Contents Section: Ignition System All sections

Ignition System - Hall Effect Audi 5000 S

Ignition System 9 illustrations ~4516 words

DESCRIPTION

Note. Ignition system on Audi Coupe GT, 4000CS Quattro, 5000S controlled by the CIS-E electronic control system. See BOSCH CIS-E ELECTRONIC CONTROL SYSTEM in FUEL SYSTEMS section.

The typical Bosch Hall Effect electronic ignition system consists of an ignition coil, Hall Effect sending unit (in distributor), Hall control unit, distributor, spark plug wires and spark plugs.

The Hall Effect sending unit receives voltage directly from the electronic control unit. Signals from the sending unit are sent to the Hall control unit through an electronic ignition control unit.

During engine operation, ignition timing is controlled by the electronic ignition control unit after receiving signals from the knock sensor, idle switch, full throttle switch and engine vacuum.

OPERATION

The Hall Effect sending unit is mounted inside the distributor. A trigger wheel passes in and out of the air gap of the Hall Effect sending unit. There is one trigger wheel shutter for each cylinder of the engine.

The Hall Effect sending unit signals the ignition control unit to make and break current flow in the primary circuit of the ignition coil. Secondary voltage is released through the high tension wiring, distributor cap and rotor to the spark plugs.

INTRODUCTION

No adjustments should be attempted on ignition system, except spark plug gap and initial ignition timing. On Audi 5000CS Turbo, idle switch, full throttle switch, and distributor position may have to be adjusted.

5000CS Turbo

  1. Turn ignition off. Install Adapter (2079 ) and turn crankshaft to TDC position. Mark on camshaft sprocket must align with upper edge of valve cover gasket.
  2. Remove distributor cap, rotor and dust cover. Loosen distributor adjustment nut. Turn distributor housing so mark on trigger wheel aligns with mark on housing. Tighten adjustment nut.
  1. Remove throttle body. Mount Protractor (3084 ) to throttle body shaft. Remove throttle lever mounting nut if necessary. Attach pointer to throttle body. Zero protractor.
  2. Connect ohmmeter to idle switch terminals. Open throttle to 20 degrees, then slowly close. Ohmmeter must indicate zero ohms 2-4 degrees before closed throttle position. Loosen screws and adjust idle switch. If switch cannot be adjusted, replace switch.
  1. Remove throttle body. Mount Protractor (3084 ) to throttle body shaft. Remove throttle lever mounting nut if necessary. Attach pointer to throttle body. Zero protractor.
  2. Connect ohmmeter to full throttle switch terminals. Slowly open throttle valve. Ohmmeter must indicate zero ohms at 53-63 degrees of throttle opening. Loosen screws and adjust switch. If switch cannot be adjusted, replace switch.

PRE-TEST PROCEDURES - ALL MODELS

  1. Ensure battery is fully charged before making tests. Check all ignition wiring.
  2. DO NOT connect any condenser to terminal No. 1 of ignition coil. Connect and disconnect test instruments only when ignition is off. DO NOT touch or remove high tension wires when engine is running or cranking.
  3. Disconnect ignition wires only when ignition is off. DO NOT crank engine unless high tension wire is removed from distributor cap and grounded with a jumper wire.
  4. When installing suppressors, use only 1000 ohms for high tension wires and 1000-5000 ohms for spark plug connectors. DO NOT wash engine when it is running. DO NOT use a battery charger for more than one minute nor exceed 16.5 charging voltage.

Audi 4000S Electronic Ignition System Wiring Diagram. Scheme 1

Scheme 1: Audi 4000S Electronic Ignition System Wiring Diagram
Scheme 1: Audi 4000S Electronic Ignition System Wiring Diagram

Knock Sensor Test

  1. Turn ignition on. Engine warning light (on instrument panel) should come on. Start engine and accelerate engine to 3000 RPM (one time only). Engine warning light must go off. If light goes out, test is completed.
  2. If light does not go out, install a fuse in test terminals of fuel pump relay for a minimum of 3 seconds. (Scheme 2) Engine warning light must start blinking. If light stays on, go to «TIMING ADVANCE TEST»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect__timing-advance-test).
  3. If light blinks in intervals of 2, the knock sensor circuit is defective. Check knock sensor tightness. If loose, tighten knock sensor to 10 ft. lbs. (14 N.m). Check for open circuit in knock sensor wiring. If wiring is okay, knock sensor or Hall control unit is defective.
  4. If light blinks in intervals of 3, check White vacuum hose to electronic ignition control unit for damage. Check for faulty throttle switches. See «IDLE & FULL THROTTLE SWITCH TEST - 4000S»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect). If okay, pressure sensor in unit is faulty.

Audi 4000S Knock Sensor Test. Scheme 2

Scheme 2: Audi 4000S Knock Sensor Test
Scheme 2: Audi 4000S Knock Sensor Test

Timing Advance Test

Perform KNOCK SENSOR TEST . If knock sensor circuit is okay, check engine idle speed and timing. Adjust if necessary. With engine running, pull off White vacuum hose from intake manifold. Plug manifold connection. Increase engine speed to 3000 RPM. Ensure timing is 20-24 degrees BTDC. If timing is incorrect, Hall control unit is defective.

HALL CONTROL UNIT TEST - 4000S

  1. Check ignition coil. See «IGNITION COIL RESISTANCE CHECK - 4000S»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect__ignition-coil-resistance-check-4000s) . Disconnect Hall control unit (in glove box) by pressing wire retaining clip. Set Digital Voltmeter (US 1119 ) on 20-volt scale. Connect voltmeter between terminals No. 2 and 4 at control unit connector.
  2. Turn ignition on. Voltmeter should indicate battery voltage. If reading is incorrect, find open circuit in wiring and repair as necessary. Connect voltmeter between terminals No. 4 and 6 at control unit connector.
  3. Crank engine and check signal from Hall Effect sending unit. Voltmeter should display some voltage. If voltage is displayed, check Hall Effect sending unit. See «HALL EFFECT SENDING UNIT TEST - 4000S»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect__hall-effect-sending-unit-test) .
  4. If no voltage is displayed, turn ignition off and reconnect Hall control unit. Disconnect connector to Hall Effect sending unit at distributor. Connect voltmeter between negative terminal No. 1 and positive terminal No. 15 on ignition coil.
  5. Turn ignition on. Initial meter reading should be 2 volts minimum. Voltage must drop to zero after 1-2 seconds. If reading is incorrect, replace Hall control unit.
  6. Check ignition coil to see if any sealing compound has leaked out. Replace coil if necessary. Briefly tap center wire from disconnected Hall sending unit connector to ground.
  7. Displayed voltage must increase a minimum of 2 volts for a short time. If reading is incorrect, replace Hall control unit. Turn ignition off. Reconnect Hall Effect sending unit.

HALL EFFECT SENDING UNIT TEST - 4000S

Note. Perform this test only if spark is absent.

Scheme 3

Scheme 3: HALL EFFECT SENDING UNIT TEST - 4000S
Scheme 3: HALL EFFECT SENDING UNIT TEST - 4000S
  1. Disconnect Hall control unit (in glove box) by pressing wire retaining clip. Set Digital Voltmeter (US 1119 ) on 20-volt scale. Connect voltmeter between terminal No. 4 and 6 at control unit connector. (Scheme 3)
  2. Crank engine and check signal from Hall Effect sending unit. Voltmeter should display some voltage. If voltage is displayed, Hall Effect sending unit is okay. (Scheme 3): Audi 4000S Hall Effect Sending Unit Test
  3. If no voltage is displayed, turn ignition off and reconnect Hall control unit. Remove connector to Hall Effect sending unit at distributor. Connect voltmeter to outer connector terminals and check voltage supply (from Hall control unit) to sending unit.
  4. Voltmeter should indicate battery voltage. Slide rubber boot away from Hall sending unit connector. Connect voltmeter between battery positive terminal and center wire on connector.
  5. Crank engine and check signal from Hall Effect sending unit. Voltmeter should display an alternating voltage. If not, ignition distributor and/or Hall control unit is defective. Reposition boot.

Voltage Test

Connect Test Lead (VW 1501 ) between feed line to throttle switches and wire connector. (Scheme 4) Turn ignition on. Check voltage between ground and connector No. 2 on test lead. Voltmeter reading should be 12 volts. Turn ignition off. If reading is incorrect, check for open circuit in wiring and repair as necessary.

Idle Switch

  1. Turn ignition on. Check voltage between ground and connector No. 1 on test lead. (Scheme 4) Voltmeter reading should be 12 volts. Open throttle body, then slowly close. While doing this, use a feeler gauge to measure point at which idle switch closes.
  2. Idle switch-to-idle stop gap should be.006-.02" (.15-.50 mm). If gap is incorrect, move switch to adjust gap. If gap is correct, check full throttle switch.

Idle & Full Throttle Switch Tests Idle switch test shown. Full throttle switch test is similar. Scheme 4

Scheme 4: Idle & Full Throttle Switch Tests Idle switch test shown. Full throttle switch test is similar.
Scheme 4: Idle & Full Throttle Switch Tests Idle switch test shown. Full throttle switch test is similar.

Full Throttle Switch

  1. Turn ignition on. With throttle body completely open, check voltage between ground and connector No. 3 on test lead. Voltmeter reading should be 12 volts.
  2. Using a screwdriver, push throttle body lever toward full throttle stop. While doing this, use a feeler gauge to measure point at which full throttle switch closes.
  3. Full throttle switch gap should be .03-.05" (.80-1.2 mm). If not, move switch to adjust gap. Ensure throttle body lever roller contacts edge of full throttle switch lever.

IGNITION COIL RESISTANCE CHECK - 4000S

  1. Turn ignition off and disconnect all wires from ignition coil. Using an ohmmeter, measure resistance between coil primary terminals No. 1 and 15. Ohmmeter reading must be .52-.76 ohms.
  2. Measure resistance between coil tower and negative coil terminal No. 1. Ohmmeter reading must be 2400-3500 ohms. If readings are incorrect, replace ignition coil.

SPARK PLUG WIRES & ROTOR - 4000S

  1. Check coil wire resistance. If radio suppression wires are used, reading should be 1200-2800 ohms. If not, reading should be zero ohms. Check resistance of spark plug wires.
  2. If radio suppression wires are used, reading should be 4600-7400 ohms. If not, reading should be 600-1400 ohms. Check spark plug connectors. If radio suppression connectors are used, reading should be 4000-6000 ohms.
  3. If not, reading should be 600-1400 ohms. Check rotor and spark plug wire distributor cap connectors. Resistance should be 600-1400 ohms. Ensure rotor is marked "R1".

IGNITION SYSTEM TEST - 5000CS TURBO

  1. Crank engine. If engine does not start, crank engine for at least 5 seconds, then leave ignition on. This will store information on components which might have caused a no-start condition. Go to step 3).
  2. If engine starts, road test vehicle. Ensure engine reaches normal operating temperature, 3000 RPM and a boost pressure of 17 psi (1.2 kg/cm 2 ). DO NOT turn ignition off after road test. Allow engine to idle. Go to step 3). NOTE: If ignition is turned off, fault memory will be erased. To reproduce fault and store in memory, vehicle must be restarted and test driven.
  3. Ensure idle switch is closed. Close full throttle switch, by hand, for about 3 seconds. Tachometer should indicate 7000 RPM and fault indicator light should come on, indicating system is ready for fault diagnosis.
  4. Depress brake pedal to actuate fault memory. If no faults are stored in memory, tachometer reading will be 7000 RPM and fault indicator light will not come on. Turn ignition off to end test.
  5. If faults are stored in memory, tachometer reading will be 1000-6000 RPM. Fault indicator light comes on and/or off. See «IGNITION SYSTEM TROUBLE SHOOTING - 5000CS TURBO»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect__ignition-system-trouble-shooting-5000cs) . Depress brake pedal again to display additional faults. NOTE: If tachometer displays 7000 RPM after depressing brake pedal and fault indicator light comes on, check voltage supply and brake light switch.
  6. On Bosch ignition controlled systems, if no additional faults are stored in memory, and if initial fault is displayed again, fault diagnosis sequence is completed. Turn ignition off. See «IGNITION SYSTEM TROUBLE SHOOTING - 5000CS TURBO»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect__ignition-system-trouble-shooting-5000cs) and correct fault(s).
  7. On Hitachi ignition controlled systems, if no additional faults are stored in memory, and tachometer indicates 7000 RPM with fault light off, fault diagnosis sequence is completed. Turn ignition off. See «IGNITION SYSTEM TROUBLE SHOOTING - 5000CS TURBO»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect__ignition-system-trouble-shooting-5000cs) and correct fault(s).
  8. On either system, if more than one fault is indicated by displays, trace and correct faults in the same order in which they were displayed. Test drive vehicle and perform «IGNITION SYSTEM TEST - 5000CS TURBO»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect__ignition-system-test-5000cs-turbo) once more to verify repairs.

IGNITION SYSTEM TROUBLE SHOOTING - 5000CS TURBO

Note. If inoperative components are discovered while trouble shooting, be sure to check wiring and connections. Tachometer Indicates 1000 RPM

Fault Indicator Light Is Off

Fault is in RPM sensor circuit. Check for open or short in circuit wiring. If wiring is okay, check RPM sensor. See RPM SENSOR TEST - 5000CS TURBO in this article.

Tachometer Indicates 1000 RPM Fault Indicator Light Is On

Fault is in engine knock control circuit. Engine knock occurs because ignition timing is retarded by engine control unit. Fill tank with fuel of specified octane rating. Check engine compression, valve clearance, fuel injection system, and turbocharger by-pass valve.

Tachometer Indicates 2000 RPM Fault Indicator Light Is Off

Fault is in ignition timing reference sensor circuit. Check for open or short in circuit wiring. If wiring is okay, check ignition timing reference sensor. See IGNITION TIMING REFERENCE SENSOR TEST - 5000CS TURBO . Ensure distributor is properly adjusted. See ADJUSTMENTS .

Tachometer Indicates 2000 RPM Fault Indicator Light Is On

Fault is in knock sensor circuit. Check for open or short in circuit wiring. If wiring is okay, replace defective knock sensor.

Tachometer Indicates 3000 RPM Fault Indicator Light Is Off

Fault is in Hall Effect sending unit circuit. Check for open or short in distributor circuit wiring. If wiring is okay, check Hall Effect sending unit. See HALL EFFECT SENDING UNIT TEST - 5000CS TURBO . Check that distributor is properly adjusted. See ADJUSTMENTS .

Tachometer Indicates 3000 RPM Fault Indicator Light Is On

Fault is in intake air temperature sensor circuit. Check for open or short in circuit wiring. If wiring is okay, check intake air temperature sensor. See INTAKE AIR TEMPERATURE SENSOR TEST - 5000CS TURBO .

Tachometer Indicates 4000 RPM Fault Indicator Light Is On

Fault is in intake coolant temperature sensor circuit. Check for open or short in circuit wiring. If wiring is okay, check coolant temperature sensor. See COOLANT TEMPERATURE SENSOR TEST - 5000CS TURBO .

Tachometer Indicates 4000 or 6000 RPM Fault Indicator Light Is Off

  1. Fault is in vacuum hose to ignition control unit. Check vacuum hose from intake manifold to ignition control unit for leaks or damage.
  2. Check for short in idle switch circuit wiring. If wiring is okay, check idle and full throttle switch. See «IDLE & FULL THROTTLE SWITCH TEST - 5000CS TURBO»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect) .

Tachometer Indicates 5000 RPM Fault Indicator Light Is Off

Pressure sensor in ignition control unit is defective. Replace ignition control unit.

Tachometer Indicates 7000 RPM Fault Indicator Light Is Off

All faults have been displayed. No faults stored in memory. Test is completed.

Tachometer Indicates 7000 RPM Fault Indicator Light Is On

Start of diagnosis sequence. Fault memory called up by activating full throttle switch with idle switch closed. If tachometer reads 7000 RPM with fault indicator light on after brake pedal is depressed, check voltage supply and brake light switch.

IGNITION COIL TEST - 5000CS TURBO

  1. Disconnect electrical leads from top of ignition coil. Connect ohmmeter between coil tower and terminal No. 1 (next to coil tower). Resistance reading should be 6500-8000 ohms.
  2. If not, check for good contact at lower ignition coil connection. If connection is okay, replace coil. Connect ohmmeter between terminals No. 1 and 15. Resistance reading should be .50-1.5 ohms. If not, replace coil.

Scheme 5

Scheme 5: SWITCHING MODULE TEST - 5000CS TURBO
Scheme 5: SWITCHING MODULE TEST - 5000CS TURBO
  1. Check Blue wire from terminal No. 1 of ignition coil to switching module for any damage or corrosion. Repair if necessary. Using a jumper wire, connect coil tower wire to ground.
  2. Unplug connector from switching module (next to ignition coil). Connect voltmeter between terminal No. 2 (Green/White wire) and ground. (Scheme 5) Install a jumper wire between terminal No. 1 and ground. NOTE: Ensure test lead connections are correct. If reversed, ignition control unit will be damaged. (Scheme 5): Switching Module Connector
  3. Crank engine. Ensure voltmeter reading is.20 volts minimum. If reading is incorrect, check wiring between switching module and control unit connector as follows.
  4. Remove control unit panel located on passenger side footwell. Unplug ignition control unit connector. Using an ohmmeter, check continuity between terminal No. 2 of control unit connector and terminal No. 1 of switching module connector.
  5. Also check continuity between terminal No. 22 of control unit connector and terminal No. 2 of switching module connector. Ohmmeter reading should be close to zero ohms for both tests. If not, check for open circuit between ignition control unit and switching module. If wiring is okay, replace control unit.

IGNITION TIMING REFERENCE SENSOR TEST - 5000CS TURBO

  1. Unplug top Black connector from plenum panel mount bracket located next to ignition coil. Connect ohmmeter between terminals No. 1 and 2 of unplugged connector. (Scheme 6) Resistance should be about 1000 ohms.
  2. If not, replace ignition timing reference sensor. If reading is correct, connect ohmmeter between terminals No. 1 and 3, then between terminals No. 2 and 3. Ohmmeter should indicate infinity.
  3. If reading is correct, replace ignition timing reference sensor. If reading is incorrect, check wiring and connections between reference sensor and control unit as follows.
  4. Remove control unit panel located on passenger side footwell. Unplug ignition control unit connector. Using an ohmmeter, check continuity between terminal No. 13 of control unit connector and terminal No. 1 of reference sensor connector.
  5. Check continuity between terminal No. 12 of control unit connector and terminal No. 2 of reference sensor connector. Also check continuity between terminal No. 28 of control unit connector and terminal No. 3 of reference sensor connector.
  6. Ohmmeter reading should be close to zero ohms for all tests. If not, check for open circuit between ignition control unit and reference sensor. If wiring is okay, check clearance between sensor and reference pin on flywheel. If okay, replace ignition control unit.

Ignition Timing Reference & RPM Sensor Connectors. Scheme 6

Scheme 6: Ignition Timing Reference & RPM Sensor Connectors
Scheme 6: Ignition Timing Reference & RPM Sensor Connectors

RPM SENSOR TEST - 5000CS TURBO

  1. Unplug Gray connector from plenum panel mount bracket (next to ignition coil, center connector). Connect ohmmeter between terminals No. 1 and 2 of unplugged connector. (Scheme 6) Resistance should be 1000 ohms.
  2. If not, replace RPM sensor. If reading is correct, connect ohmmeter between terminals No. 1 and 3, then between terminals No. 2 and 3. Ohmmeter should indicate infinity. If not, replace RPM sensor. If reading is correct, check wiring and connections between reference sensor and control unit as follows.
  3. Remove control unit panel located on passenger side footwell. Unplug ignition control unit connector. (Scheme 7) Using an ohmmeter, check continuity between terminal No. 29 of control unit connector and terminal No. 1 of RPM sensor connector.
  4. Check continuity between terminal No. 11 of control unit connector and terminal No. 2 of RPM sensor connector. Also check continuity between terminal No. 28 of control unit connector and terminal No. 3 of RPM sensor connector.
  5. Ohmmeter reading should be close to zero ohms for all tests. If not, check for open circuit between ignition control unit and RPM sensor. If wiring is okay, replace ignition control unit.

INTAKE AIR TEMPERATURE SENSOR TEST - 5000CS TURBO

  1. Without unplugging connector, slide back rubber boot and connect ohmmeter between intake air temperature sensor terminals. Ohmmeter should indicate 400-700 ohms. If not, check wiring and connections between sensor and control unit as follows.
  2. Remove control unit panel located on passenger side footwell. Unplug ignition control unit connector. Using an ohmmeter, check continuity between terminal No. 23 of control unit connector and terminal No. 1 of sensor connector. Ohmmeter reading should be close to zero ohms.
  3. Check continuity between terminal No. 23 of control unit connector and terminal No. 2 of sensor connector. Ohmmeter reading should be 400-700 ohms. Check continuity between terminal No. 24 of control unit connector and terminal No. 1 of sensor connector. Ohmmeter reading should be close to zero ohms.
  4. Check continuity between terminal No. 24 of control unit connector and terminal No. 2 of sensor connector. (Scheme 7) Ohmmeter reading should be 400-700 ohms. If readings are incorrect, cut wires at intake air temperature sensor.
  5. Connect ohmmeter between terminals of intake temperature sensor. Ohmmeter reading should be 400-700 ohms. If reading is correct, check for short circuit in wiring between control unit and sensor. If wiring is okay, replace control unit. Solder NEW air temperature sensor to wires.

Ignition Control Unit Connector. Scheme 7

Scheme 7: Ignition Control Unit Connector
Scheme 7: Ignition Control Unit Connector

COOLANT TEMPERATURE SENSOR TEST - 5000CS TURBO

  1. Disconnect wire from coolant temperature sensor. Connect ohmmeter between ground and coolant temperature sensor. Ohmmeter reading should be 60-1000 ohms.
  2. If not, replace coolant temperature sensor. If reading is correct, check sensor wiring. Remove ignition control unit panel located on passenger side footwell. Unplug ignition control unit connector.
  3. Using an ohmmeter, check continuity between terminal No. 10 of control unit connector and coolant temperature sensor wire. Ohmmeter reading should be close to zero ohms. If reading is incorrect, check for open circuit in wiring. If reading is correct, replace ignition control unit.

Unplug connector for idle and full throttle switches at throttle body. Connect voltmeter between center connector terminal and ground. Turn ignition on. Voltmeter reading should be about 12 volts. Turn ignition off. If reading is incorrect, check for open circuit in wiring and repair as necessary.

  1. Connect ohmmeter between terminals No. 1 and 2. (Scheme 8) Ohmmeter reading should be close to zero ohms. Actuate switch with throttle lever. Ohmmeter should indicate infinity.
  2. If readings are incorrect, adjust idle switch. See «ADJUSTMENTS»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect). Repeat test. If readings are still incorrect, replace and adjust idle switch. If readings are correct, check full throttle switch.

Idle & Full Throttle Switch Tests. Scheme 8

Scheme 8: Idle & Full Throttle Switch Tests
Scheme 8: Idle & Full Throttle Switch Tests
  1. Connect ohmmeter between terminals No. 2 and 3. (Scheme 8) Ohmmeter should indicate infinity. Actuate switch with throttle lever. Ohmmeter reading should be zero ohms.
  2. If readings are incorrect, adjust full throttle switch. See «ADJUSTMENTS»(/audi/5000-s/1985-1988/remont/ignition-system/#ignition-system-hall-effect). Repeat test. If readings are still incorrect, replace full throttle switch. If readings are correct, check wiring between throttle switch and ignition control unit as follows.
  3. Remove control unit panel located on passenger side footwell. Unplug ignition control unit connector. Using an ohmmeter, check continuity between terminal No. 20 of control unit connector and terminal No. 1 of idle/full throttle switch connector.
  4. Also check continuity between terminal No. 26 of control unit connector and terminal No. 3 of idle/throttle switch connector. Ohmmeter reading should be close to zero ohms for both tests.
  5. If readings are incorrect, check for open circuit in wiring between idle/throttle switch connector and ignition control unit. If wiring is okay, replace ignition control unit.

HALL EFFECT SENDING UNIT TEST - 5000CS TURBO

Note. Ignition coil wire from distributor must always be grounded when checking Hall Effect sending unit.

  1. Remove protective cover from Hall Effect sending unit (on distributor) and unplug connector from unit. Connect voltmeter to connector terminals No. 1 and 3. Turn ignition on. Voltmeter reading should be 9 volts minimum.
  2. If reading is incorrect, check for open circuit in wiring to sending unit. If reading is correct, turn ignition off. Install connector cover. Connect voltmeter between terminals No. 1 and 2.
  3. Plug distributor connector back into Hall Effect sending unit. Turn ignition on. Remove distributor cap, rotor, and dust cover. Turn crankshaft by hand until rotor window clears sending unit. Voltmeter should indicate 4 volts minimum.
  4. Turn crankshaft until rotor window aligns with sending unit. Voltmeter should indicate 0-.5 volts. Turn ignition off. If readings are correct, check wiring between Hall Effect sending unit and ignition control unit as follows.
  5. Remove control unit panel located on passenger side footwell. Unplug ignition control unit connector. Using an ohmmeter, check continuity between terminal No. 4 of control unit connector and terminal No. 1 of sending unit connector.
  6. Check continuity between terminal No. 27 of control unit connector and terminal No. 2 of sending unit connector. Also check continuity between terminal No. 25 of control unit connector and terminal No. 3 of sending unit connector. Ohmmeter reading should be close to zero ohms for all 3 tests.
  7. If readings are incorrect, check for open circuit in wiring between sending and ignition control units. If readings are correct, replace ignition control unit.

IGNITION CONTROL UNIT VOLTAGE SUPPLY TEST - 5000CS TURBO

  1. Remove control unit panel located on passenger side footwell. Unplug ignition control unit connector. Turn ignition on. Using a voltmeter, check voltage between terminals No. 35 and 18, and between terminals No. 35 and 9. Voltmeter reading should be close to 12 volts.
  2. Turn ignition off. Connect voltmeter between terminals No. 32 and 9. Turn ignition on and apply brake pedal. Voltmeter reading should be close to 12 volts. Turn ignition off. If readings are incorrect, check for open circuit in brake light wiring. If wiring is okay, replace brake light switch.

Fuel Pump Relay Signal

  1. Pull fuel pump relay out of fuse block/relay panel. Connect voltmeter between terminals No. 46 and 47 of relay panel sockets. (Scheme 9) Briefly actuate starter. Voltmeter should indicate close to 9.5 volts.
  2. If reading is correct, check fuel pump relay and fuel pump. If reading is incorrect, connect voltmeter between terminal No. 46 of relay panel socket and ground. Turn ignition on. Voltmeter should indicate close to 12 volts.
  3. If reading is incorrect, check for open circuit in wiring. If reading is correct, check wiring between ignition control unit and fuse block/relay panel as follows.
  4. Remove control unit panel located on passenger side footwell. Unplug ignition control unit connector. Using an ohmmeter, check continuity between terminal No. 21 of control unit connector and socket No. 47 of fuse block/relay panel.
  5. Ohmmeter reading should be close to zero ohms. If reading is incorrect, check for open circuit in wiring. If reading is correct, replace ignition control unit.

Fuel Pump Relay Signal Test. Scheme 9

Scheme 9: Fuel Pump Relay Signal Test
Scheme 9: Fuel Pump Relay Signal Test

Tachometer Signal

  1. Remove control unit panel located on passenger's side footwell. DO NOT unplug ignition control unit. Connect voltmeter between ground and terminal No. 7 of control unit. Pull back on boot to gain access to terminal.
  2. Connect tachometer to engine. Start and run engine at 2000 RPM. Voltmeter reading should be close to 1.3 volts. If reading is incorrect, replace ignition control unit.
  3. If reading is correct, but vehicle tachometer does not correspond with test tachometer, check wiring between terminal No. 7 of ignition control unit and vehicle tachometer. Repair if necessary.

DISASSEMBLY

Note. The Hall Effect sending unit and trigger wheel (rotor) cannot be removed on Saab models. Entire distributor must be replaced.

  1. Loosen ground strap and remove static shield from distributor cap (if equipped). Remove cap, rotor, carbon brush and spring. Remove dust cover. Remove connector from distributor by depressing retaining clip.
  2. Remove retaining snap ring. Carefully pry off trigger wheel. Remove washers. Remove screws and lift out Hall sending unit and connecting socket. Remove base plate and vacuum unit. Remove pin and distributor drive pinion and shims.

REASSEMBLY

  1. To assemble, reverse disassembly procedure. If a new Hall Effect sending unit (generator) is being installed, a special repair kit is available containing all necessary parts.
  2. Replace seals, and check components for cracks, corrosion and wear. Clean cap before installing. If trigger wheel was bent during removal, it must be replaced.