Hard Trouble Code E15: 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.

Trouble code indicates that coolant sensor signal voltage is too high. Condition will be observed in engine data display as coolant temperature reading (parameter P.0.4) of B40 to B35°C. Possible causes are: Open coolant sensor, defective wiring, terminals, etc., or ECM not processing coolant signal properly.

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

If opposite failure mode (shorted sensor) is created, then self-diagnostics can be used to detect failure by displaying engine data parameter P.0.4. With opposite failure created, parameter P.0.4 should display reading of 148-151°C. To create shorted sensor signal, disconnect coolant sensor and jumper harness terminals together. If reading is now 148-151°C, ECM and wiring harness are okay. Fault must be in sensor connector or coolant sensor itself.
If reading is 147°C or less, then there is an open in signal circuit No. 410, in sensor ground circuit No. 476A, or in ECM . If reading is now 148-151°C with circuit No. 410 jumpered to ground, an open exists in circuit No. 476A.
If reading remains 147°C or less with circuit No. 410 jumpered to ground at ECM, either ECM connector or ECM is faulty. If reading is now 148-151°C, an open exists in circuit No. 410.