Long-Term Fuel Trim, Idling Speed. Upper Limit
UPPER LIMIT
EFI-231 and EFI-232 Long-term fuel trim, part load and idling respectively
Checking mass air flow (MAF) sensor
- Ignition on.
Connect a voltmeter between mass air flow (MAF) sensor connector terminals 2 and 4.
The voltmeter should read 0.1 - 0.2 V.
OK - Checking for air leakage in the intake system
Not OK - Replacing component
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Replacing component
- Try a new mass air flow (MAF) sensor.
Select "Continue" when the fault has been repaired.
Continue - Verification
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Checking for air leakage in the intake system
Check for air leakage according to Check for air leaks in the intake system Air Leaks In the Intake System, Checking.
Is there any air leakage?
Yes - Verification
No - Checking for air leakage in the exhaust system
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Checking for air leakage in the exhaust system
Check for air leakage according to Checking for air leakage in the exhaust system Checking for Air Leakage In the Exhaust System.
Is there any air leakage?
Yes - Verification
No - Checking fuel and residual pressures
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Checking fuel and residual pressures
- Check fuel and residual pressure.
Is fuel pressure OK?
Yes - Checking pulsation damper
No - Verification
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Checking pulsation damper
- Disconnect the Volvo Scan Tool (ST) from the VIDA station and use it in stand-alone mode.
- Test drive the car.
- Use the Volvo Scan Tool (ST) to read off the value of the short-term fuel trim and engine speed (RPM).
- Drive the car on a flat road.
- Maintain engine speed at 1250 rpm.
- Watch short-term fuel trim
The value should oscillate around 1.000.
OK - Checking ground terminals, connector B
Not OK - Replacing component
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Replacing component
- Try a new pulsation damper.
Select "Continue" when the fault has been repaired.
Continue - Verification
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Checking ground terminals, connector B
Connecting the breakout box
Connecting breakout box to connector B (gray)
- 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.
Will the engine control module (ECM) be connected when readings are taken on connector B?
Yes - Checking ground terminal #B28
No - Return to the fault-tracing procedure where it was interrupted.
No Fault Found
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Checking ground terminal #B28
- Ignition off.
- Switch off all equipment that takes power from the battery (courtesy lighting, radio etc).
- Connect control module.
Connect an ohmmeter between #28 (#B28) on the breakout box and battery positive terminal.
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.
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 B (gray)
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FAULT FOUND - Verification
No Fault Found - Verification
FAULT-TRACING FAILED - Verification
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Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied as follows:
- Ignition off.
- Reconnect connectors and reinstall components.
- Disconnect the Volvo Scan Tool (ST) from the VIDA station and use it in stand-alone mode.
Use the Volvo Scan Tool (ST) to read off the value of long-term fuel trim.
- Test drive the car.
- Watch the long-term fuel trim value until it switches to completed.
If diagnostic trouble code (DTC) EFI-231/232 is stored it should have intermittent status.
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 mass air flow (MAF) sensor
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