Note on Intermittents

Do not investigate an intermittent Code 31 if the vehicle has a history of engine backfires. A backfire can produce a manifold pressure greater than 106 kPa and set this code. If an intermittent Code 31 is being set, manipulate related wiring while observing engine data parameter .0.2. If the failure is induced, the MAP reading will jump from its normal value to the "shorted" reading of 106 to 108 kPa. This will help to isolate the location of the malfunction.