Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, 2002 Chevrolet RV Cutaway, and 2002 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

Intermittent DTCs P0251, P0370 and P1216 may be caused by air entering the fuel system when fuel levels get below 1/8 of a tank while performing hard acceleration or turning maneuvers. DTC P0251, P0370 and P1216 may set if the vehicle has run out of fuel. Customer driving habits should be checked to determine if vehicle has been performing in these manners. If the vehicle has been performing under these conditions, bleed fuel system of all air and test drive vehicle.

When the PCM is in backup fuel, fast idle and poor performance problems will exist. If DTC P0251 is also stored, the Snapshot mode on the scan tool should be used to in order to properly identify a malfunction. DTC P0335, P1216, and P1217 may set along with this DTC.

The least likely cause of failure is the PCM.

RPM VS HERTZ FOR HIGH RESOLUTION SIGNAL

RPM	Hertz
700	2987
800	3413
900	3840
1000	4267
1100	4693
1200	5120
1300	5547
1400	5973
1500	6400
1600	6827
1700	7253
1800	7680
1900	8170
2000	8533
2100	8960
2200	9387
2300	9813
2400	10,240
2500	10,667
2600	11,093
2700	11,520
2800	11,947
2900	12,373
3000	12,800
3100	13,227
3200	13,653
3300	14,080