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System/component Tests Saab 9000 I

Testing & Diagnostics ~1800 words

INTRODUCTION

Prior to testing separate components or systems, it is highly recommended that all procedures listed in BASIC TESTING article be performed. Since many computer controlled and monitored components will set a trouble code if they malfunction, it is also recommended that self-diagnosis be performed. See G - TESTS W/ CODES article.

Note. Testing of individual components does not isolate possible shorts or opens in the control harness of electronically controlled systems. Use an ohmmeter to isolate shorts or opens in harness. All voltage tests should be performed with a Digital Volt Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless specifically stated different in testing procedures.

PRESSURE TRANSDUCER

  1. Remove panel underneath dashboard (driver side). Unplug connector from Automatic Performance Control (APC) unit. Connect vacuum pump and pressure gauge to pressure transducer hose.
  2. Connect ohmmeter between Black/White and Green/Red wires of APC connector. Measure resistance. Resistance should be 8-13 ohms at atmospheric pressure.
  3. Increase pressure to approximately 14.5 psi (10.2 kg/cm 2 ) and then let it drop to 8.7 psi (.61 kg/cm 2 ), at the same time tapping lightly on APC bracket. Resistance at 8.7 psi (.61 kg/cm 2 ) should be 83-93 ohms. If readings are not as specified, replace pressure transducer.

WASTEGATE SOLENOID VALVE

Test solenoid valve by jumping battery voltage to solenoid valve terminals. Valve should open when battery voltage is applied and close when power is removed. Replace wastegate solenoid valve if not opening or closing as specified.

AIR MASS METER

  1. Disconnect air mass meter. Check filament condition, electrical connectors and wiring. If okay, check filament burn-off function.
  2. With air mass meter disconnected from air cleaner (electrical connector connected), start and warm engine to 158°F (65°C). Let engine idle. Increase engine speed to 2500 RPM, release throttle and let idle again.
  3. Turn engine off. After 4 seconds, the filament should glow brightly for about one second. If filament does not glow, disconnect air mass meter connector.
  4. Connect voltmeter in place of air mass meter. Start engine. Increase engine speed to 2500 RPM, release throttle and let idle. Turn engine off. After 4 seconds, voltmeter should read about 4 volts for about one second.
  5. If voltmeter reads okay, replace air mass meter. If voltmeter does not read any voltage, check wiring and connections. If wiring and connection are okay, test system with a known good ECU. If condition is rectified, replace original ECU.

COOLANT TEMPERATURE SENSOR

Disconnect sensor connector. Check resistance between sensor connectors. Resistance should be 2280-2720 ohms at 68°F (20°C) or 290-365 ohms at 176°F (80°C).

HALL EFFECT SENSOR

  1. Turn ignition on. To measure voltage supply to Hall effect sensor, connect voltmeter between EZK Ignition Control Unit terminals No. 4 and No. 10. Reading should be 10 volts or battery voltage.
  2. To measure signal from Hall Effect sensor, connect voltmeter between EZK Ignition Control Unit terminals No. 10 and No. 24. Slowly turn engine over by hand. Reading should be less than 0.4 volt (shutter wheel in open position) or greater than 3.0 volts (shutter wheel in closed position.
  3. If readings are not as specified, check wiring harness and connectors. If wiring and connectors are okay, replace Hall Effect sensor (located behind crankshaft pulley).
  4. If engine runs, but has poor performance, check ignition timing. If at any time the timing marks appear to be moving back and forth, the sensor should be inspected for chips or loosely mounted magnet. Repair or replace as necessary.

OXYGEN (O2) SENSOR

  1. Disconnect 2-wire O2 sensor connector. Measure resistance between the 2 White wires. Resistance should be about 4 ohms.
  2. Set voltmeter to 2-volt DC scale. Connect voltmeter leads between Black sensor wire and ground. Start engine. Voltmeter reading should vary between 100-900 mV, as the sensor temperature increases and the air/fuel mixture changes. Replace O2 sensor is resistance is not as specified or sensor reaction time is too slow.

THROTTLE POSITION SWITCH (TPS)

  1. Disconnect ECU connector and remove cover. Connect ohmmeter leads between ECU harness connector pins No. 3 and No. 25. With throttle valve at idle position, continuity should be present.
  2. If continuity is not present, check Gray wire between ECU pin No. 3 and TPS, Black/White wire between ECU pin No. 25 and ground, or Black/White wire between TPS and ground.
  3. Rotate throttle valve to open position. Circuit should be broken the moment the throttle is opened. If not, adjust TPS. See «ADJUSTMENTS»(/saab/9000/i-1984-1994/remont/adjustments/#adjustments) article in this section.
  4. Connect ohmmeter between ECU harness connector pins No. 3 and No. 11. Check that circuit is broken when throttle valve leaves the idle position. Connect ohmmeter leads between ECU harness connector pins No. 25 and No. 12. Continuity should be present, when throttle is opened beyond 72 degrees position or approaching wide open throttle.
  5. If circuit is not closed, check Green/Red wire between ECU pin No. 12 and TPS, Black/White wire between ECU pin No. 25 and ground, or Black/White wire between TPS and ground. If wires are okay, replace TPS.

RELAYS

Note. For ECU and relay terminal numbers or location, refer to WIRING DIAGRAMS article in this section.

Fuel Pump Relay

  1. Disconnect ECU and air mass meter connectors. Connect ECU wire harness pins No. 21 and No. 17 to ground and check voltage at Blue/Red wire in engine compartment bulkhead connector. Check voltage at No. 14 fuse terminals.
  2. If voltage is present at fuse but not at Blue/Red wire at bulkhead connector, check Green/Red wire between fuel pump relay and fuse. If voltage is not present from any of the above, go to next step.
  3. Check voltage at terminal No. 30 (Red wire) to relay. Check voltage at terminal No. 86 on fuel pump relay. If voltage is not present, check voltage at terminal No. 87 on fuel pump relay. If voltage is still not present, go to next step.
  4. Using a jumper wire or Test Lead (83 93 894 ), jumper fuel pump terminal No. 85 to ground. Voltage should now be present at terminals No. 87 and 87B. If not, replace fuel pump relay.

Main Relay

  1. Disconnect ECU and air mass meter connectors. Connect ECU wire harness terminal No. 21 to ground. Voltage should be present at ECU wire harness terminal No. 9 and at air mass meter pin No. 5. If not, go to next step.
  2. Remove glove compartment box and pull out fuse/relay panel. Check voltage at main relay pins No. 30 (Red wire) and No. 86 (Red wire). If voltage is not present, check wiring from battery positive source to fuse/relay panel.
  3. Connect main relay terminal No. 85 (Yellow/White wire) to ground. Check voltage at terminal No. 87 (Gray/White wire) and at terminal No. 87B (Brown/White wire). If voltage is present, go to next step. If voltage was not present, replace main relay.
  4. If from step 3), voltage was present. Check the following: Yellow/White wire between main relay terminal No. 85 and ECU pin No. 21. Green/White wire between main relay terminal No. 87 through the pressure switch to fuel pump relay terminal No. 86. Brown/White wire between main relay terminal No. 87B and air mass meter pin No. 5.

Wastegate Solenoid

Test solenoid valve by jumping battery voltage to solenoid valve terminals. Valve should open when battery voltage is applied and close when power is removed. Replace wastegate solenoid valve if not opening or closing as specified.

FUEL DELIVERY

Note. For fuel system pressure testing, see BASIC TESTING article.

Fuel Injector(s)

Disconnect injector electrical connector. Measure resistance between the 2 injector terminals. Resistance should be 16 ohms with injector at 68°F (20°C). If resistance is not as specified, replace injector.

Automatic Idle Control (AIC)

  1. Remove glove compartment box. Pull out relay panel. Remove relay "E" (delay relay) for the A/C system. Start engine. Connect jumper lead between pins No. 16 and No. 30 on relay holder. Engine speed should increase. If not, go to next step.
  2. Check for voltage at pin No. 30 on relay holder. Check for continuity between Red/White wire and pin No. 16 on relay holder and pin No. 16 on ECU. If voltage is present at pin No. 30 and circuit to ECU is good, check operation of A/C delay relay. If relay is okay, substitute a known good ECU. If problem is rectified, replace original ECU.

Auxiliary Air Valve

  1. Connect tachometer to engine. Start and warm engine to normal operating temperature. Turn A/C on and check engine RPM. Engine speed should initially decrease and return to normal idle speed.
  2. If RPM did not return to normal idle speed, check for battery voltage at auxiliary air valve harness connector. If voltage is present, check resistance between auxiliary air valve terminals. Resistance should be 40-60 ohms. Replace auxiliary air valve is resistance is not as specified. If voltage was not present, go to next step.
  3. Check Red wire between power distribution panel (A/C relay) and auxiliary air valve through the connector in engine compartment. Check Black ground wire. If wiring is okay, check operation of A/C relay.

IGNITION SYSTEM

Note. For basic ignition checks, see BASIC TESTING article.

EGR Thermostatic Valve

Disconnect thermostatic valve hoses. Blow through valve. Valve should be closed when temperature is less than 110°F (43°C) with on-off and two-port systems, 68°F (20°C) on 900 models, and 86°F (30°C) on 9000 models with proportional systems. Valve should be open when temperature is greater than that listed. Replace EGR thermostatic valve if defective.

Two-Port & On-Off EGR System

  1. Warm engine to normal operating temperature. Connect tachometer to engine. Slowly increase engine speed. Note engine RPM at which valve begins to open.
  2. Opening RPM should be as specified. See «EGR VALVE SPECIFICATIONS»(/saab/9000/i-1984-1994/remont/testing-diagnostics/#systemcomponent-tests) table. Check EGR valve and thermostatic valve if RPM and valve opening is not within specification.
ApplicationEngine RPM
On-Off1900
Two-Port2300-2900

EGR VALVE SPECIFICATIONS

Proportional EGR Valve

  1. With engine at idle and at normal operating temperature, disconnect EGR valve hose at thermostatic valve. Connect vacuum pump to hose. Apply vacuum to EGR valve. Engine idle should become rough.
  2. Reconnect vacuum hose. Disconnect hose between EGR valve and throttle valve housing. Apply pressure to hose using radiator tester. Engine idle should become rough. Replace EGR valve is idle was not affected.

Two-Port & On-Off EGR Valve

With engine at idle, disconnect EGR valve vacuum hose at thermostatic valve. Connect vacuum pump to hose. Apply vacuum to EGR valve. Engine idle should become rough or engine may stall. If not, check or clean EGR ports. If ports are okay, replace EGR valve.

Dashpot

  1. Warm engine to normal operating temperature. Connect tachometer. Adjust idle speed to specification. See «ADJUSTMENTS»(/saab/9000/i-1984-1994/remont/adjustments/#adjustments) article in this section.
  2. Increase engine speed to 3000 RPM. Release throttle, noting time between release of throttle and return to idle. Deceleration time should be 3-5 seconds from contact of plunger.

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