Engine Running Diagnostic Mode

The engine running diagnostic mode is a powertrain control module (PCM) strategy which is separate from the normal operating strategy. When in this mode, the engine is running and does not turn off, as it does during normal operation. The engine RPM may be increased to the desired speed as the vehicle is in the pedal follower mode. To activate the engine running diagnostic mode the gear selector must be in the PARK position, and the ignition cycled to the START position. The engine is allowed to idle as long as the powertrain and hybrid-electric systems operate within the calibrated limits. The powertrain malfunction indicator (wrench) flashing once per second indicates the vehicle is in the engine running diagnostic mode. This mode is helpful whenever the engine must stay running for diagnostics and repairs that require the engine to be idling for extended time. Carry out the following sequence to activate this mode:

• apply the parking brake
• place the gear selector in the PARK position
• ignition in the OFF position
  NOTE: Do not start the engine.
• ignition in the ON position with the engine OFF
• within 5 seconds of the ignition in the ON position, fully apply the accelerator pedal and hold for 10 seconds
• within 5 seconds release the accelerator pedal, shift the gear selector to the DRIVE position and fully apply the accelerator pedal
• hold the accelerator pedal fully applied for 10 seconds
• release the accelerator pedal and shift the gear selector to the PARK position

If the sequence is correctly executed the powertrain malfunction indicator (wrench) flashes once per second when the gear selector is shifted to the PARK position. The engine may be started by cycling the ignition to the START position. The PCM exits the engine running mode when the gear selector is shifted to any gear other than PARK, when the ignition is turned to the OFF or ACC position, or the powertrain or hybrid-electric system exceeds calibrated limits.