Circuit Diagnosis

Circuit fault diagnosis may be carried out on all multiport fuel injected (MFI) vehicles, using a multi-meter or the RTC 6834 handheld tester. The RTC 6834 displays the diagnostic trouble codes stored by the Engine Control Module and guides the technician through a series of diagnostic checks. Complete operational and diagnostic instructions are provided with the handheld tester's memory cards.

Whichever instrument is used to diagnose the fuel injection system problem, the following preliminary checks must be performed before proceeding with any diagnostic procedures.

CAUTION: CATALYST EXHAUST
If the engine is misfiring or fails to start within 12 seconds the cause must be rectified. Failure to do so will cause irreparable damage to the catalysts. After rectification, the engine must be run at 1500 RPM with no load for three minutes to purge any accumulation of fuel in the system.