Part 2
Faulty signal (Continued)
EFI-355 Mass air flow (MAF) sensor, faulty signal
Checking signal ground
- Ignition off.
- Mass air flow (MAF) sensor disconnected.
Connect an ohmmeter between mass air flow (MAF) sensor connector terminal 2 and ground.
The ohmmeter should read approximately 0 ohms.
OK - Checking power cable
Not OK - Checking control module connector
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Checking control module connector
- Ignition off.
- Mass air flow (MAF) sensor disconnected.
- Check control module connector for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Control module connected.
Connect an ohmmeter between mass air flow (MAF) sensor connector terminal 2 and ground.
The ohmmeter should read approximately 0 ohms.
OK - Checking power cable
Not OK - Checking for contact resistance and oxidation
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Checking for contact resistance and oxidation
- Check cable between mass air flow (MAF) sensor terminal 2 and engine control module (ECM) #A5 for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Verification
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Checking power cable
- Ignition off.
- Disconnect mass air flow (MAF) sensor.
- Ignition on.
Connect a voltmeter between mass air flow (MAF) sensor connector terminal 3 and ground.
The voltmeter should read battery voltage.
OK - Checking the signal cable
Not OK - Checking for contact resistance and oxidation
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Checking for contact resistance and oxidation
- Check cable between mass air flow (MAF) sensor terminal 3 and main relay (2/32) terminal 3 for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Verification
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Checking the signal cable
- Ignition on.
- Mass air flow (MAF) sensor disconnected.
Connect a voltmeter between mass air flow (MAF) sensor connector terminal 4 and ground.
The voltmeter should read 0 - 1 V.
OK - Connecting breakout box A
Not OK - Checking for contact resistance and oxidation
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Checking for contact resistance and oxidation
- Check cable between mass air flow (MAF) sensor terminal 4 and engine control module (ECM) #A4 for contact resistance and oxidation according to according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Verification
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Checking the signal cable
- Ignition off.
- Connect mass air flow (MAF) sensor.
- Breakout box connected.
- Connect control module.
Connect a voltmeter between terminals #5 (A5) and #4 (A4).
The voltmeter should read 0.1 - 0.2 V.
OK - Fault-tracing information
Not OK - Replacing component
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Fault-tracing information
- The cause of the diagnostic trouble code (DTC) has been loose connections in the mass air flow (MAF) sensor and/or engine control module (ECM) connectors. Check connectors for contact resistance and oxidation and remedy in accordance with Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Verification
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Replacing component
- Try a new mass air flow (MAF) sensor.
Continue - Verification
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Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied as follows.
- Reconnect connectors and reinstall components.
- ERASE DTC
- Run the engine to operating temperature (above 80°C (176°F)).
- Go into diagnostic test menu.
- Test drive the car
- Watch EFI-355, wait until the status of EFI-355 switches to tested.
- Read diagnostic trouble codes (DTCs).
EFI-355 should not be stored.
OK - VERIFIED
Not OK - VERIFICATION FAILED
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VERIFIED - FAULT FOUND
VERIFICATION FAILED - Fault-tracing information
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Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Checking throttle position (TP) sensor
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Connecting breakout box A
Connecting the breakout box
Connecting breakout box to connector A (black)
- Ignition off.
- Disconnect control module.
Note! The engine control module (ECM) must not be removed from the car until the main relay has interrupted its power supply. This may take up to 150 seconds after the ignition has been switched off. Cars with immobilizer 245 seconds.
Connect adapter 951 1351 ADAPTOR 86-PIN 951 1351 Adaptor 86-Pin to engine control module (ECM) connector and connect breakout box 981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 to adapter.
Continue - Checking ground terminals
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Checking ground terminals
- Ignition off.
- Switch off all equipment that takes power from the battery (courtesy lighting, radio etc).
- Connect an ohmmeter between the battery negative terminal and:
- #13 (#A13) on the breakout box.
- #28 (#28) on the breakout box.
- #42 (#A42) on the breakout box.
The ohmmeter should read approximately 0 ohms for all readings.
OK - Return to the fault-tracing procedure where it was interrupted.
No Fault Found
Not OK - Checking for an open-circuit
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Checking for an open-circuit
- Check ground terminal 31/71 on the right side member and cables to this for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Check ground lead between engine and chassis for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault and contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Select "Continue" when the fault has been repaired.
Continue - Verification
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Verification
Verification
Hint: After carrying out the repair check that the fault has been remedied.
- Ignition off.
- Control module disconnected.
- Switch off all equipment that takes power from the battery (courtesy lighting, radio etc).
Connect an ohmmeter between battery negative terminal and #13/#28/#42 on the breakout box.
The ohmmeter should read approximately 0 ohms for all readings.
OK - VERIFIED
Not OK - VERIFICATION FAILED
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VERIFIED - FAULT FOUND
VERIFICATION FAILED - Fault-tracing information
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Fault-tracing information
Information
Fault-tracing information
The fault should be diagnosed and remedied. Since this is not the case the fault-tracing process has failed.
Complete the fault-tracing for those fault or try again.
Do you want to terminate fault-tracing at this time?
Yes - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Connecting breakout box to connector A (black)
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FAULT FOUND - Checking the signal cable
No Fault Found - Checking the signal cable
FAULT-TRACING FAILED - Checking the signal cable
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