Hard Trouble Code E31: Notes

NOTE: If this code is not displayed during second pass of diagnostic codes, it is an intermittent failure and cannot be diagnosed using this procedure.

The ECM supplies 5 volt signal to pin C (circuit No. 474) of MAP sensor and supplies ground path to pin A (circuit No. 476X). The MAP signal from pin B (circuit No. 432) is a variable voltage that is dependent on manifold pressure.

Trouble code indicates that voltage signal from MAP sensor is too high. This situation can be observed in engine data display parameter "P.0.2" as reading of 106-108 kPa. Possible causes of this condition are: Defective MAP sensor, defective wiring, terminals, etc., or ECM is not able to process signals properly.

NOTE: The following step numbers refer to the numbers in the accompanying flow chart(s).

If opposite condition (low MAP signal) can be created, the self-diagnostics can be used to detect failure by displaying engine data parameter "P.0.2". With opposite condition created, parameter "P.0.2" should display reading of 14-16 kPa. To create low sensor signal, disconnect MAP sensor connector. If reading is 14-16 kPa, then problem must be faulty MAP sensor. If reading is 17 kPa or greater, then there is a short to voltage in wiring or ECM.