DTC P1686


DTC P1686	Metering oil pump control circuit low flow side problem
DETECTION CONDITION	• The PCM monitors the input signal from the metering oil pump switch when the metering oil pump stepping motor is more than the standard step. If the input signal is off, the PCM determines that the metering oil pump control circuit has a problem on the low flow side. Diagnostic support note • This is a continuous monitor (CCM). • The MIL illuminates if the PCM detects the above malfunction condition in the first drive cycle. • PENDING CODE is available if the PCM detects the above malfunction condition. • FREEZE FRAME DATA is available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• Metering oil pump malfunction • Metering oil pump switch malfunction • Connector or terminal malfunction • Open circuit in wiring harness between main relay terminal C and metering oil pump terminal C • Short to GND in wiring harness between main relay terminal C and metering oil pump terminal C • Open circuit in wiring harness between main relay terminal C and metering oil pump terminal D • Short to GND in wiring harness between main relay terminal C and metering oil pump terminal D • Open circuit in wiring harness between metering oil pump terminal A and PCM terminal 2V • Short to GND in wiring harness between metering oil pump terminal A and PCM terminal 2V • Open circuit in wiring harness between metering oil pump terminal E and PCM terminal 2W • Short to GND in wiring harness between metering oil pump terminal E and PCM terminal 2W • Open circuit in wiring harness between metering oil pump terminal B and PCM terminal 2Y • Short to GND in wiring harness between metering oil pump terminal B and PCM terminal 2Y • Open circuit in wiring harness between metering oil pump terminal F and PCM terminal 2AB • Short to GND in wiring harness between metering oil pump terminal F and PCM terminal 2AB • Open circuit in wiring harness between metering oil pump switch terminal A and PCM terminal 2N • Open circuit in wiring harness between metering oil pump switch terminal C and PCM terminal 1U • PCM malfunction


STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related service 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.
2		No	Go to the next step.
3	INSPECT METERING OIL PUMP CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the metering oil pump connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 13.
3		No	Go to the next step.
4	INSPECT METERING OIL PUMP POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GND • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between the following circuits: – Metering oil pump terminal C (wiring harness-side) and body GND – Metering oil pump terminal D (wiring harness-side) and body GND • Is the voltage B+?	Yes	Go to the next step.
4		No	Repair or replace the wiring harness for a possible open circuit or short to GND, then go to Step 13.
5	INSPECT METERING OIL PUMP CONTROL CIRCUIT FOR SHORT TO GND • Turn the ignition switch off. • Inspect for continuity between the following circuits: – Metering oil pump terminal A (wiring harness-side) and body GND – Metering oil pump terminal E (wiring harness-side) and body GND – Metering oil pump terminal B (wiring harness-side) and body GND – Metering oil pump terminal F (wiring harness-side) and body GND • Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to GND, then go to Step 13.
5		No	Go to the next step.
6	INSPECT METERING OIL PUMP • Inspect the metering oil pump. (See METERING OIL PUMP INSPECTION.) • Is there any malfunction?	Yes	Replace the metering oil pump, then go to Step 13. (See METERING OIL PUMP REMOVAL/INSTALLATION.)
6		No	Go to the next step.
7	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 terminal, then go to Step 13.
7		No	Go to the next step.
8	INSPECT METERING OIL PUMP CONTROL CIRCUIT FOR OPEN CIRCUIT • Turn the ignition switch off. • Inspect for continuity between the following circuits: – Metering oil pump terminal A (wiring harness-side) and PCM terminal 2V (wiring harness-side) – Metering oil pump terminal E (wiring harness-side) and PCM terminal 2W (wiring harness-side) – Metering oil pump terminal B (wiring harness-side) and PCM terminal 2Y (wiring harness-side) – Metering oil pump terminal F (wiring harness-side) and PCM terminal 2AB (wiring harness-side) • Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for a possible open circuit, then go to Step 13.
9	INSPECT METERING OIL PUMP SWITCH CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the metering oil pump switch connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 13.
9		No	Go to the next step.
10	INSPECT METERING OIL PUMP SWITCH • Inspect the metering oil pump switch. (See METERING OIL PUMP SWITCH INSPECTION.) • Is there any malfunction?	Yes	Replace the metering oil pump, then go to Step 13. (See METERING OIL PUMP REMOVAL/INSTALLATION.)
10		No	Go to the next step.
11	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 terminal, then go to Step 13.
11		No	Go to the next step.
12	INSPECT METERING OIL PUMP SWITCH SIGNAL CIRCUIT FOR OPEN CIRCUIT • Turn the ignition switch off. • Inspect for continuity between the following circuits: – Metering oil pump switch terminal A (wiring harness-side) and PCM terminal 2N (wiring harness-side) – Metering oil pump switch terminal C (wiring harness-side) and PCM terminal 1U (wiring harness-side) • Is there continuity?	Yes	Go to the next step.
12		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
13	VERIFY TROUBLESHOOTING OF DTC P1686 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the WDS or equivalent. • Start the engine. • Is the same DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION.)
13		No	Go to the next step.
14	VERIFY AFTER REPAIR PROCEDURE • Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE.) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE.)
14		No	DTC troubleshooting completed.