Drive Engine Run-up (DERU) Load Test
To carry out this test, proceed as follows:^ Block the front and rear wheels.
WARNING: BLOCK THE FRONT AND REAR WHEELS, AND APPLY THE PARKING BRAKE AND THE SERVICE BRAKE, OR INJURY TO PERSONNEL CAN RESULT.
CAUTION: Do not carry out the Engine Load Test for more than five seconds or damage to the transmission or transaxle can result.
^ Apply the parking brake and the service brake.
^ Install a tachometer.
^ Shift the transmission into DRIVE, and increase and decrease the engine rpm between an idle to approximately 2000 rpm. Note the engine rpm and, if possible, determine the vibration frequency.
^ Repeat the test in REVERSE.
^ If the vibration/noise is duplicated when carrying out this test, inspect the engine and transmission or transaxle mounts.
^ If the concern is definitely engine speed-related, carry out the Engine Accessory Test to narrow down the source. Engine Accessory Drive Test
^ Proceed as necessary.