Diagnostic Aids

Ensure that fuel level is in same range as customer concern. Verify fuel level readings match specifications. See FUEL LEVEL SPECIFICATIONS table. Fuel level (%) specification is available on scan tool in PCM ENHANCED EVAP data list.

FUEL LEVEL SPECIFICATIONS

Gauge Reading	Ohms	Amount of Fuel (%)	Amount of Fuel (Gallons)
E	40-72	0-10	0-2
1/4	128	32	6
1/2	168	54	10
3/4	206	75	14
F	234-250	91-100	17-18.5
Low Fuel Indicator On	94	16	3
Low Fuel Indicator Off	100	18	3.5

Fig 1: Locating In-Line Connector C420

Courtesy of GENERAL MOTORS CORP.

Fig 2: Identifying In-Line Connector C420 Terminals

Courtesy of GENERAL MOTORS CORP.