Part 2
Faulty signal (Continued)
EFI-425 Rear heated oxygen sensor (HO2S), control
Measuring line pressure
- Read off line pressure from pressure gauge.
Line pressure should be 300 kPa (3.0 kp/cm2).
OK - Checking fuel filter
Low - Line pressure too low
High - Line pressure too high
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Line pressure too high
- Ignition off.
- Remove the cable between the relay base terminals 1 and 3.
- Disconnect return line from pressure regulator.
- Blow through the line into the fuel tank.
Is cable OK?
Yes - Measuring line pressure, Stop fuel pump
No - Measuring line pressure, Checking for blockage
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Stop fuel pump
- Switch off ignition.
- Disconnect jumper lead between relay base terminals 1 and 3.
Press Continue.
Continue - DONE
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DONE - Replacing component
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Replacing component
Try a new pressure regulator according to:
- (B5202S/B5252S Fenix 5.2)
- (other engines)
Select "Continue" when the fault has been repaired.
Continue - Connecting pressure gauge
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DONE - Checking for blockage
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Checking for blockage
- Check if there is a blockage in the return line. Clean and replace as necessary.
Select "Continue" when the fault has been repaired.
Continue - Connect pressure gauge
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Starting fuel pump (FP)
- Remove central electrical unit cover.
- Remove fuel pump relay (position 103 in electrical distribution unit).
- Connect a cable between relay base terminals 1 and 3.
- Ignition on.
Fuel pump (FP) should operate.
Continue - Measuring line pressure
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Measuring line pressure
- Read off line pressure from pressure gauge.
Line pressure should be 300 kPa (3.0 kp/cm2).
OK - Stop fuel pump
Not OK - Fault-tracing information
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Line pressure too low
Caution! Do not allow pressure to exceed 600 kPa (6.0 kPa/cm2).
- Squeeze the return line and check is the pressure rises.
Did the pressure increase?
Yes - Measuring line pressure, Replacing component
No - Check filter gauze at fuel pump (FP). If it is OK: Replace pump according to Fuel pump, replacement Fuel Pump, Replacement and then measure line pressure.
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DONE - Replacing component
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Replacing component
Try a new pressure regulator.
Select "Continue" when the fault has been repaired.
Continue - Connect pressure gauge
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DONE - Checking for blockage
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Checking for blockage
- Check filter gauze at fuel pump (FP). If it is OK: Replace fuel pump (FP) according to Fuel pump, replacement Fuel Pump, Replacement
Select "Continue" when the fault has been repaired.
Continue - Connect pressure gauge
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Checking fuel filter
Caution! Do not allow pressure to exceed 600 kPa (6.0 kPa/cm2).
- Squeeze the return line and check if pressure increases quickly or slowly.
Did the pressure increase quickly?
Yes - Checking pressure regulator, pressure reduction
No - Replacing component
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Replacing component
- Replace fuel filter according to Fuel filter, replacement Removal and Replacement.
Select "Continue" when the fault has been repaired.
Continue - Start fuel pump
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Start fuel pump
- Connect jumper lead across relay base terminals 1 and 3.
- Switch on ignition.
Fuel pump should run.
Continue - DONE
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DONE - Checking fuel filter
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Checking fuel filter
Caution! Do not allow pressure to exceed 600 kPa (6.0 kPa/cm2).
- Squeeze the return line and check if pressure increases quickly or slowly.
Did the pressure increase quickly?
Yes - Stop fuel pump
No - Fault-tracing information
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Checking pressure regulator, pressure reduction
- Connect vacuum pump 999 5843 VACUUM PUMP AT 999 5843 Vacuum Pump AT to pressure regulator.
- Pump air out of the regulator.
- Check that line pressure drops by the same amount as the pressure in the regulator drops.
- 300 kpa - negative pressure = line pressure
- Disconnect the hose from the vacuum pump.
Line pressure should return to 300 kPa.
OK - Checking pressure regulator, pressure increase
Not OK - Replacing component
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Replacing component
Try a new pressure regulator.
Select "Continue" when the fault has been repaired.
Continue - Checking pressure regulator, pressure reduction
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Checking pressure regulator, pressure reduction
- Connect vacuum pump 999 5843 VACUUM PUMP AT 999 5843 Vacuum Pump AT to pressure regulator.
- Pump air out of the regulator.
- Check that line pressure drops by the same amount as the pressure in the regulator drops.
- 300 kpa - negative pressure = line pressure
- Disconnect the hose from the vacuum pump.
Line pressure should return to 300 kPa.
OK - Stop fuel pump
Not OK - Fault-tracing information
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Checking pressure regulator, pressure increase
- Connect pressure tester 998 5496 ENGINE COOLANT SYSTEM - PRESSURE TESTER 998 5496 Engine Coolant System - Pressure Tester and pressure gauge 999 5230 PRESSURE METER 999 5230 Pressure Meter to pressure regulator.
- Pump up pressure.
- Check that line pressure rises by the same amount as the pressure in the regulator.
- 300 kpa + overpressure = line pressure.
- Disconnect hose from pressure tester.
Line pressure should return to 300 kPa.
OK - Checking residual pressure
Not OK - Replacing component
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Replacing component
Try a new pressure regulator.
Select "Continue" when the fault has been repaired.
Continue - Checking pressure regulator, pressure increase
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Checking pressure regulator, pressure increase
- Connect pressure tester 998 5496 ENGINE COOLANT SYSTEM - PRESSURE TESTER 998 5496 Engine Coolant System - Pressure Tester and pressure gauge 999 5230 PRESSURE METER 999 5230 Pressure Meter to pressure regulator.
- Pump up pressure.
- Check that line pressure rises by the same amount as the pressure in the regulator.
- 300 kpa + overpressure = line pressure.
- Disconnect hose from pressure tester.
Line pressure should return to 300 kPa.
OK - Stop fuel pump
Not OK - Fault-tracing information
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Checking residual pressure
- Ignition off.
- Disconnect cable between relay base terminals 1 and 3.
- Reinstall the fuel pump relay.
Line pressure must not drop below 200 kPa in less than 20 minutes.
OK - Disconnecting pressure gauge
Not OK - Replacing component
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Replacing component
- Incorrect residual pressure readings may be due to leakage from injectors, connections, pressure regulator, fuel pump non-return valve or lines. Repair as necessary.
Select "Continue" when the fault has been repaired.
Continue - Checking residual pressure
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Checking residual pressure
- Ignition off.
- Disconnect cable between relay base terminals 1 and 3.
- Reinstall the fuel pump relay.
Line pressure must not drop below 200 kPa in less than 20 minutes.
OK - Stop fuel pump
Not OK - Fault-tracing information
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Disconnecting pressure gauge
- Ignition off.
- Start draining unit.
- Turn pressure gauge cock to mid-position.
- Lock adapter (valve closed as in picture 1).
- Disconnect adapter from valve.
- Stop draining unit.
- Reinstall equipment.
Caution! Remember to reinstall valve safety cap.
Continue - No Fault Found
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Stop fuel pump (FP)
- Switch off the ignition.
- Disconnect cable between relay base terminals 1 and 3.
- Reinstall the fuel pump relay.
Select "Continue".
Continue - Disconnecting pressure gauge
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Disconnecting pressure gauge
- Ignition off.
- Start draining unit.
- Turn pressure gauge cock to mid-position.
- Lock adapter (valve closed as in picture 1).
- Disconnect adapter from valve.
- Stop draining unit.
- Reinstall equipment.
Caution! Remember to reinstall valve safety cap.
Continue - FAULT FOUND
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Stop fuel pump (FP)
- Ignition off.
- Disconnect cable between relay base terminals 1 and 3.
- Reinstall the fuel pump relay.
Continue - Disconnecting pressure gauge
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Disconnecting pressure gauge
- Ignition off.
- Start draining unit.
- Turn pressure gauge cock to mid-position.
- Lock adapter (valve closed as in picture 1).
- Disconnect adapter from valve.
- Stop draining unit.
- Reinstall equipment.
Caution! Remember to reinstall valve safety cap.
Select "Continue" when the fault has been repaired.
Continue - FAULT-TRACING FAILED
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Fault-tracing information
Information
Fault-tracing information
The previous test indicates that a repair must be made before continuing with fault-tracing. You cannot proceed with the fault-tracing tests at this point.
Continue - No Fault Found
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Connect pressure gauge
- Supplement pressure gauge 999 5011 MANOMETER 999 5011 Manometer with nipple 998 9725 Adapter 998 9725 Adapter and adapter 999 5479 ADAPTER 999 5479 Adapter before use.
- Connect adapter to valve on fuel rail, with adapter in locked position (valve closed as in picture 1).
- Turn pressure gauge cock so it faces adapter 999 5479 ADAPTER 999 5479 Adapter.
- Connect other pressure gauge connector to fuel draining unit 981 2270 PUMP TROLLEY 981 2270 Pump Trolley , 981 2273 PUMP 981 2273 Pump and 981 2282 Tank 981 2282 Tank.
- Unlock adapter (illustration 2 valve open).
Continue - Starting fuel pump
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No Fault Found - Replacing component
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Replacing component
- Try a new rear heated oxygen sensor (HO2S).
Continue - Verification
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Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied as follows:
- Ignition off.
- Front and rear heated oxygen sensors (HO2S) connected.
- Disconnect the Volvo Scan Tool (ST) from the VIDA station and use it in stand-alone mode.
- Start the engine and idle it.
- Go into the Diagnostic Test Mode (DTM) menu.
- Watch EFI-425, wait until the status of EFI-425 switches to tested. This can take up to 15 minutes after the engine has been started.
- Read off diagnostic trouble codes (DTCs).
If EFI-425 is stored they 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 compression
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