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.
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HOMESERVICE MANUALSSAAB19879000 L4-1985CC 2.0L DOHCREPAIR AND DIAGNOSISPOWERTRAIN MANAGEMENTCOMPUTERS AND CONTROL SYSTEMSAIR FLOW METER/SENSORTESTING AND INSPECTIONMASS AIR FLOW SENSOR
1987 Saab 9000 L4-1985cc 2.0L DOHC
Mass Air Flow Sensor
1987 Saab 9000 L4-1985cc 2.0L DOHCSECTION Mass Air Flow Sensor
Checking the Mass Air Flow Sensor
In connection with diagnosing faults on and/or carrying out repairs to the LH 2.2 and LH 2.4 fuel injection systems on mode; year 1988 and later cars, it is important to observe the following:
Mass air flow sensor of plastic
This mass air flow sensor must never be replaced by a mass air flow sensor of aluminium. If this is done, the LH control module will be ruined.
LH control module in fuel injection systems with a mass air flow sensor of plastic
This LH control module must never be replaced by an LH control module designed for fuel injection systems with a mass air flow sensor of aluminium.
Mass air flow sensors of plastic are fitted to the following versions of model year 1988 cars:
9000i/S with catalytic converter (LH 2.4)
9000i without catalytic converter (LH 2.2)
All versions of model year 1989 and later cars are fitted with mass air flow sensors of plastic.
Tools:
- Multimeter
- Breakout Box 86 11 006
- Test cables 86 11 410
The CHECK ENGINE lamp (MIL) comes on in the event of a fault in the mass air flow sensor.
1 Unplug the mass air flow sensor connector. Connect a multimeter to the mass air flow sensor pins as follows:
LH 2.2 -M1987
pins 3 and 6
LH 2.2 M1988-1990 + LH 2.4.2 without cat
pins 2 and 6
Adjust to 380 ohms. If it cannot be adjusted to the correct value, change the mass air flow sensor.
2 Check that the pins in the connector and mass air flow sensor are free from corrosion. Check that the wire mesh screens in the ends of the mass air flow sensor are intact and clean.
3 Check the positive power supply with the ignition switch in the Drive position.
-M1987 fuel injection engine, -M1988 turbo engine
pin 2
M1988- fuel injection engine, M1989- turbo engine
pin 5
4 Check the connection to ground
-M1987 fuel injection engine, -M1988 turbo engine
pin 4
M1988- fuel injection engine, M1989- turbo engine
pin 1
5 Check filament (hot wire) burn-off, see "Checking the operation of filament (hot wire) burn-off". Checking the Operation of Filament (Hot Wire) Burn-Off
6 Connect Breakout Box 86 11 006 to the LH control module and check the load signal on pin 7.
1.2 - 1.5 V with the ignition switched on (engine not running)
1.0 - 5.0 V, depending on engine load (engine running).
7 Unplug the Breakout Box and connect the LH control module.
Check the CO reading (cars without cat.), see "Checking and adjusting the CO value". ZZZZZZ
Check the pulse ratio (LH 2.2 with cat. -1987 fuel injection engine and -M1988 turbo engine), see "Adjustment/replacement of components". ZZZZZZ
In connection with diagnosing faults on and/or carrying out repairs to the LH 2.2 and LH 2.4 fuel injection systems on mode; year 1988 and later cars, it is important to observe the following:
Mass air flow sensor of plastic
This mass air flow sensor must never be replaced by a mass air flow sensor of aluminium. If this is done, the LH control module will be ruined.
LH control module in fuel injection systems with a mass air flow sensor of plastic
This LH control module must never be replaced by an LH control module designed for fuel injection systems with a mass air flow sensor of aluminium.
Mass air flow sensors of plastic are fitted to the following versions of model year 1988 cars:
9000i/S with catalytic converter (LH 2.4)
9000i without catalytic converter (LH 2.2)
All versions of model year 1989 and later cars are fitted with mass air flow sensors of plastic.
Tools:
- Multimeter
- Breakout Box 86 11 006
- Test cables 86 11 410
The CHECK ENGINE lamp (MIL) comes on in the event of a fault in the mass air flow sensor.
1 Unplug the mass air flow sensor connector. Connect a multimeter to the mass air flow sensor pins as follows:
LH 2.2 -M1987
pins 3 and 6
LH 2.2 M1988-1990 + LH 2.4.2 without cat
pins 2 and 6
Adjust to 380 ohms. If it cannot be adjusted to the correct value, change the mass air flow sensor.
2 Check that the pins in the connector and mass air flow sensor are free from corrosion. Check that the wire mesh screens in the ends of the mass air flow sensor are intact and clean.
3 Check the positive power supply with the ignition switch in the Drive position.
-M1987 fuel injection engine, -M1988 turbo engine
pin 2
M1988- fuel injection engine, M1989- turbo engine
pin 5
4 Check the connection to ground
-M1987 fuel injection engine, -M1988 turbo engine
pin 4
M1988- fuel injection engine, M1989- turbo engine
pin 1
5 Check filament (hot wire) burn-off, see "Checking the operation of filament (hot wire) burn-off". Checking the Operation of Filament (Hot Wire) Burn-Off
6 Connect Breakout Box 86 11 006 to the LH control module and check the load signal on pin 7.
1.2 - 1.5 V with the ignition switched on (engine not running)
1.0 - 5.0 V, depending on engine load (engine running).
7 Unplug the Breakout Box and connect the LH control module.
Check the CO reading (cars without cat.), see "Checking and adjusting the CO value". ZZZZZZ
Check the pulse ratio (LH 2.2 with cat. -1987 fuel injection engine and -M1988 turbo engine), see "Adjustment/replacement of components". ZZZZZZ
RENDER: 1.0x
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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.