Diagnostic procedure
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STEP
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INSPECTION
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RESULTS
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ACTION
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1
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• Does engine idle rough?
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Yes
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Go to symptom troubleshooting "No.8 Engine runs rough/rolling idle".
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No
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Go to next step.
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2
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Turn off A/C switch and fan switch.
Does A/C magnetic clutch engauge?
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Yes
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Go to symptom troubleshooting "No.24 A/C is always on or A/C compressor runs continuously."
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No
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Go to next step.
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3
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Verify following:
• Proper routing and no damage of vacuum lines
• IAC valve is connected properly.
• No air leakage from intake-air system
Are all items okay?
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Yes
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Go to next step.
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No
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Service as necessary.
Repeat Step 3.
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4
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Connect WDS or equivalent to DLC-2.
Retrieve any continuous memory, KOEO and KOER DTCs.
Are there any DTCs displayed?
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Yes
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DTC is displayed:
Go to appropriate DTC test.
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No
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No DTC is displayed:
Go to next step.
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5
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Does idle speed drop or stall when disconnecting IAC valve?
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Yes
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Go to next step.
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No
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Inspect following:
• Circuit from IAC valve to PCM connector terminal 4G or 4J for open and short
• IAC valve for sticking
If okay, go to next step.
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6
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Disconnect vacuum hose between purge solenoid valve and intake manifold from purge solenoid valve side.
Plug opening end of vacuum hose.
Drive vehicle.
Does engine condition improve?
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Yes
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Inspect evaporative emission control system.
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No
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Go to next step.
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7
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Connect WDS or equivalent to DLC-2.
Access TP, MAF, VSS, BOO, CPP and CPP/PNP PIDs.
Monitor each PID while driving vehicle.
(See PCM INSPECTION [L3].)
Are PIDs okay?
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Yes
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Intermittent concern exists.
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No
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TP PID: Inspect TP sensor. MAF PID: Inspect MAF sensor. VSS PID: Inspect VSS. BOO PID: Inspect brake switch. CPP PID: Inspect clutch switch. CPP/PNP PID: Inspect neutral switch. |
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8
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Verify test results.
• If okay, return to diagnostic index to service any additional symptoms.
• If malfunction remains, replace PCM.
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