Compression Check: Testing and Inspection

INSPECT COMPRESSION
a. Set the vehicle to inspection mode.
b. Warm up and stop the engine.
c. Remove the intake air surge tank.

NOTICE: If the throttle body connector is disconnected because the DTC is detected in inspection, always reconnect it.

d. Disconnect the injector connectors.
e. Remove the ignition coils.

NOTICE: If the ignition coil assembly connector is disconnected because the DTC is detected in inspection, always reconnect it.

f. Remove the spark plugs.





g. Inspect cylinder compression pressure.
(1) Insert a compression gauge into the spark plug hole.
(2) Connect the intelligent tester (with CAN VIM) to the DLC3.

NOTICE: Check the fully charged battery to indicate HV battery voltage in ECU data monitor.

(3) Enter ACTIVE TEST MODE on the intelligent tester.
(4) While cranking the engine, measure the compression pressure.
Compression pressure: 0.98 MPa (10 kgf/cm2, 142 psi)
Minimum pressure: 0.74 MPa (7.5 kgf/cm2, 107 psi)
Difference between each cylinder: 100 kPa (1.0 kgf/cm2, 15 psi)

NOTICE:
^ Check other cylinder's compression pressure in the same way.
^ This measurement must be done as quickly as possible.
^ After performing all the procedures, be sure to clear DTCs stored in the memory. Then, check that the normal system code is output.

(5) If the cylinder compression is low, pour a small amount of engine oil into the cylinder through the spark plug hole and inspect again.

HINT: If adding oil increases the compression, the piston rings and/or cylinder bore may be worn or damaged.
If pressure stays low, a valve may be stuck or seated improperly, or there may be leakage past the gasket.