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DTC P1686

DTC P1686 Metering oil pump NO. 2 circuit low input
DETECTION CONDITION 
  • The PCM monitors the input voltage from the metering oil pump NO. 2 when the battery voltage is more than 8 V  and the metering oil pump NO. 2 control signal turned from ON to OFF. If the input voltage is less than the specification, the PCM determines that the metering oil pump NO. 2 circuit has a malfunction.

Diagnostic support note 
  • This is a continuous monitor (other).
  • The MIL does not illuminate.
  • FREEZE FRAME DATA (Mode 2/Mode 12) is not available.
  • The DTC is stored in the PCM memory.
POSSIBLE CAUSE 
  • Metering oil pump NO. 2 connector or terminals malfunction
  • Metering oil pump driver connector or terminals malfunction
  • Short to ground or open circuit in metering oil pump NO. 2 power supply circuit
    • Short to ground in wiring harness between main relay terminal C and metering oil pump NO. 2 terminal B
    • Metering oil pump NO. 2 related fuse malfunction
    • Open circuit in wiring harness between main relay terminal C and metering oil pump NO. 2 terminal B
  • Short to ground or open circuit in metering oil pump driver power supply circuit
    • Short to ground in wiring harness between main relay terminal C and metering oil pump driver terminal C
    • Metering oil pump driver related fuse malfunction
    • Open circuit in wiring harness between main relay terminal C and metering oil pump driver terminal C
  • PCM connector or terminals malfunction
  • Short to power supply in wiring harness between metering oil pump driver terminal F and PCM terminal 1 AA
  • Short to ground in wiring harness between metering oil pump NO. 2 terminal A and PCM terminal 1F
  • Short to ground in wiring harness between metering oil pump driver terminal E and PCM terminal 1F
  • Metering oil pump NO. 2 malfunction
  • Metering oil pump driver malfunction
  • Open circuit in wiring harness between metering oil pump NO. 2 terminal A and PCM terminal 1F
  • Open circuit in wiring harness between metering oil pump driver terminal E and PCM terminal 1F
  • PCM malfunction
G07878140
DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 VERIFY RELATED REPAIR INFORMATION AVAILABILITY 
  • Verify related Service Bulletins and/or on-line repair information availability.
  • Is any related repair information available?
 Yes Perform repair or diagnosis according to the available repair information.
  • If the vehicle is not repaired, go to the next step.
No Go to the next step.
2 INSPECT METERING OIL PUMP NO. 2 CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch off.
  • Disconnect the metering oil pump NO. 2 connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 11.
No Go to the next step.
3 INSPECT METERING OIL PUMP DRIVER CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch off.
  • Disconnect the metering oil pump driver connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 11.
No Go to the next step.
4 INSPECT METERING OIL PUMP NO. 2 AND METERING OIL PUMP DRIVER POWER SUPPLY CIRCUIT FOR SHORT TO GROUND OR OPEN CIRCUIT 
  • Metering oil pump NO. 2 and metering oil pump driver connectors are disconnected.
  • Turn the ignition switch to the ON position (engine off).
  • Measure the voltage between the following circuits:
    • Metering oil pump NO. 2 terminal B (wiring harness-side) and body ground
    • Metering oil pump driver terminal C (wiring harness-side) and body ground
  • Is the voltage B+  ?
 Yes Go to the next step.
No Inspect the metering oil pump NO. 2 and metering oil pump driver related fuse.
  • If the fuse is melt:
    • Repair or replace the wiring harness for a possible short to ground.
    • Replace the fuse.
  • If the fuse is deterioration:
    • Replace the fuse.
  • If the fuse is normal:
    • Repair or replace the wiring harness for a possible open circuit.

Go to Step 11.
5 INSPECT PCM CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch off.
  • Disconnect the PCM connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 11.
No Go to the next step.
6 INSPECT METERING OIL PUMP DRIVER CIRCUIT FOR SHORT TO POWER SUPPLY 
  • Metering oil pump NO. 2, metering oil pump driver and PCM connectors are disconnected.
  • Turn the ignition switch to the ON position (engine off).
  • Measure the voltage between metering oil pump driver terminal F (wiring harness-side) and body ground.
  • Is there any voltage?
 Yes Repair or replace the wiring harness for a possible short to power supply, then go to Step 11.
No Go to the next step.
7 INSPECT METERING OIL PUMP NO. 2 AND METERING OIL PUMP DRIVER CONTROL CIRCUIT FOR SHORT TO GROUND 
  • Metering oil pump NO. 2, metering oil pump driver and PCM connectors are disconnected.
  • Turn the ignition switch off.
  • Inspect the continuity between metering oil pump driver terminal E (wiring harness-side) and body ground.
  • Is there continuity?
 Yes Repair or replace the wiring harness for a possible short to ground following:
  • Between metering oil pump NO. 2 terminal A and PCM terminal 1F
  • Between metering oil pump driver terminal E and PCM terminal 1F

Go to Step 11.
No Go to the next step.
8 INSPECT METERING OIL PUMP NO. 2 
 Yes Replace the metering oil pump NO. 2, then go to Step 11.
(See METERING OIL PUMP REMOVAL/INSTALLATION ).
No Go to the next step.
9 INSPECT METERING OIL PUMP DRIVER 
 Yes Replace the metering oil pump driver, then go to Step 11.
(See METERING OIL PUMP DRIVER REMOVAL/INSTALLATION ).
No Go to the next step.
10 INSPECT METERING OIL PUMP NO. 2 AND METERING OIL PUMP DRIVER CONTROL CIRCUIT FOR OPEN CIRCUIT 
  • Metering oil pump NO. 2, metering oil pump driver and PCM connectors are disconnected.
  • Turn the ignition switch off.
  • Inspect for continuity between the following circuits:
    • Metering oil pump NO. 2 terminal A (wiring harness-side) and PCM terminal 1F (wiring harness-side)
    • Metering oil pump driver terminal E (wiring harness-side) and PCM terminal 1F (wiring harness-side)
  • Is there continuity?
 Yes Go to the next step.
No Repair or replace the wiring harness for a possible open circuit, then go to the next step.
11 VERIFY TROUBLESHOOTING OF DTC P1686 COMPLETED 
  • Make sure to reconnect all disconnected connectors.
  • Clear the DTC from the PCM memory using the M-MDS.

    (See AFTER REPAIR PROCEDURE ).

  • Perform the KOER self test.

    (See KOEO/KOER SELF TEST ).

  • Is the same DTC present?
 Yes Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION ).
No Go to the next step.
12 VERIFY AFTER REPAIR PROCEDURE 
 Yes Go to the applicable DTC inspection.
(See DTC TABLE ).
No DTC troubleshooting completed.
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