NO. 21 ENGINE NOISE [L3]
| 21 | ENGINE NOISE |
|---|---|
| DESCRIPTION | Engine noise from under hood |
| POSSIBLE CAUSE | Squeal, click or chirp noise: Improper engine oil level Improper drive belt tension Rattle sound noise: Loose parts Hiss sound noise: Vacuum leakage Loose spark plug Air leakage from intake-air system Improper variable air duct (VAD) control system operation Rumble or grind noise: Improper drive belt tension Rap or roar noise: Exhaust system looseness Other noise: Camshaft friction gear noise or MLA noise Timing chain noise |
POSSIBLE CAUSE DESCRIPTION
NO. 22 VIBRATION CONCERNS (ENGINE) [L3]
| 22 | VIBRATION CONCERNS (ENGINE) |
|---|---|
| DESCRIPTION | Vibration from under hood or driveline |
| POSSIBLE CAUSE | Loose attaching bolts or worn parts Components malfunction such as worn parts |
POSSIBLE CAUSE DESCRIPTION
Vibration Method
- If malfunction occurs or becomes worse while driving on a rough road or when engine is vibrating, perform the steps below. NOTE: There are several reasons vehicle or engine vibration could cause an electrical malfunction. Check the following: Connectors not fully seated. Wiring harnesses not having full play. Wires laying across brackets or moving parts. Wires routed too close to hot parts. An improperly routed, improperly clamped, or loose harness can cause wiring harness to become pinched between parts. The connector joints, points of vibration, and places where wiring harnesses pass through the firewall and body panels are the major areas to be checked.
Scheme 172
- Connect M-MDS to DLC-2.
- Turn ignition switch to ON position (Engine off). NOTE: If engine starts and runs, perform the following steps during idle.
- Access PIDs for the switch you are inspecting.
- Turn switch on manually.
- Slightly shake each connector or wiring harness vertically and horizontally while monitoring the PID. If PID value is unstable, check for poor connection.
Scheme 173
- Connect M-MDS to DLC-2.
- Turn ignition switch to ON position (Engine off). NOTE: If engine starts and runs, perform the following steps during idle.
- Access PIDs for the switch you are inspecting.
- Slightly shake each connector or wiring harness vertically and horizontally while monitoring the PID. If PID value is unstable, check for poor connection.