ENGINE TROUBLESHOOTING

FOREWORD

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• When the customer reports a vehicle malfunction, check the malfunction indicator lamp (MIL) indication and diagnostic trouble code (DTC), then diagnose the malfunction according to the following flowchart:
• /square4 If a DTC exists, diagnose the applicable DTC inspection. (See DTC TABLE .)
• /square4 If no DTC exists and the MIL does not illuminate or flash, diagnose the applicable symptom troubleshooting. (See QUICK DIAGNOSTIC CHART .)
• *: Malfunction Indicator Lamp (MIL), Generator Warning Light, Security Light

INTERMITTENT CONCERN TROUBLESHOOTING

Vibration Method

• If a malfunction occurs or becomes worse while driving on a rough road or when the engine is vibrating, perform the steps below.

NOTE:

• There are several reasons why vehicle or engine vibration could cause an electrical malfunction. Some of the things to check for are:
• /square4 Connectors not fully seated.
• /square4 Wiring harnesses not having full play.
• /square4 Wires laying across brackets or moving parts
• /square4 Wires routed too close to hot parts.
• An improperly routed, improperly clamped, or loose wiring harness can cause wiring to become pinched between parts.
• The connector joints, points of vibration, and places where wiring harnesses pass such as through the firewall and body panels are the major areas to be checked.

Inspection Method for Switch Connectors or Wires

1. Connect the WDS or equivalent to the DLC-2.
2. Turn ignition switch to ON position (Engine OFF).

NOTE:

• If the engine starts and runs, perform the following steps at idle.

3. Access the PIDs for the switch you are inspecting.
4. Turn the switch on manually.
5. Shake each connector or wiring harness a bit vertically and horizontally while monitoring the PID.

• If the PID value is unstable, check for poor connection.

Inspection Method for Sensor Connectors or Wires

1. Connect the WDS or equivalent to the DLC-2.
2. Turn the ignition switch to the ON position (Engine off).

NOTE:

• If the engine starts and runs, perform the following steps at idle.

3. Access the PIDs for the switch you are inspecting.
4. Shake each connector or wiring harness a bit vertically and horizontally while monitoring the PID.

• If the PID value is unstable, check for poor connection.

Inspection Method for Sensors

1. Connect the WDS or equivalent to the DLC-2.
2. Turn the ignition switch to the ON position (Engine off).

NOTE:

• If the engine starts and runs, perform the following steps at idle.

3. Access the PIDs for the switch you are inspecting.

4. Vibrate the sensor slightly with your finger.

• If the PID value is unstable or malfunction occurs, check for poor connection or poorly mounted sensor or both.

Inspection Method for Actuators or Relays

1. Connect the WDS or equivalent to the DLC-2.
2. Turn the ignition switch to the ON position (Engine off).

NOTE:

• If the engine starts and runs, perform the following steps at idle.

3. Prepare the output state control function