COMPRESSION PRESSURE CHECK

1. Before inspection, set the vehicle to the pre-inspection condition (Refer to PRE-INSPECTION CONDITION

2. Disconnect the ignition coil connectors and then remove all of the ignition coils and spark plugs (Refer to IGNITION COIL REMOVAL AND INSTALLATION

note	Do not disconnect the injector connectors.

warning

Keep away from the spark plug hole when cranking. If compression is measured with water, oil, fuel, etc., that has come from cracks inside the cylinder, these materials will become heated and will gush out from the spark plug hole, which is dangerous.

caution

While the scan tool (M.U.T.-III SE) is communicating with the vehicle, the electric motor switch may not be turned off and no normally. Therefore, when you turn off the electric motor switch for that communication, wait for several seconds and then turn on it again (do not turn on it immediately).

3. Illuminate the READY (ready to drive) indicator. Then cover the spark plug hole with a shop towel etc. Select item No. 4 (Engine compression measurement) from Test of PHEV-ECU special function on the scan tool (M.U.T.-III SE). Crank the engine, and then check that no foreign material is adhering to the shop towel.

4. Set compression gauge to one of the spark plug holes.

5. Select item No. 4 (Engine compression measurement) from Test of PHEV-ECU special function on the scan tool (M.U.T.-III SE) and measure the compression pressure.

Standard value (at engine speed of 300 r/min):

1,150 kPa (167 psi)

Limit (at engine speed of 300 r/min):

Minimum 850 kPa (123 psi)

6. Measure the compression pressure for all the cylinders, and check that the pressure differences of the cylinders are below the limit.

Limit: Maximum 98 kPa (14 psi)

7. If there is a cylinder with compression or a compression difference that is outside the limit, pour a small amount of engine oil through the spark plug hole, and repeat the operations in steps from 5 to 7.

(1) If the compression increases after oil is added, the cause of the malfunction is a worn or damaged piston ring and/or cylinder inner surface.

(2) If the compression does not rise after oil is added, the cause is a burnt or defective valve seat, or pressure is leaking from the gasket.

8. Install the spark plugs and ignition coils (Refer to IGNITION COIL REMOVAL AND INSTALLATION

9. If the diagnostic trouble code is set during the check, use the scan tool (M.U.T.-III SE) to erase the diagnostic trouble codes.