Group 28 Engine Control Module (ECM) Diagnostic Trouble Codes (DTCs) ECM SPN 637, Crankshaft Position Sensor (CKP) – MID 128 SID 22 36 Type of fault: FMI Description: Fault Condition: Possible Symptoms: Possible Cause:
FMI 2 • Data erratic, intermittent or incorrect • Intermittent or weak signal • MIL illuminated • Yellow electronic malfunction lamp illuminated • Increased fuel consumption • Imprecise engine timing • Increased fuel consumption • Uneven cylinder balancing • Power loss • Smoke • Faulty CKP sensor harness • Faulty CKP sensor FMI 3 • Voltage above normal, or shorted to high source • Missing Signal CKP sensor • Open in the CKP sensor circuit • Short to battery in the CKP sensor circuit • Short to ground in the CKP sensor circuit • MIL illuminated • Yellow electronic malfunction lamp illuminated • Possible loss of engine power • Increased fuel consumption • Faulty CKP sensor harness • Faulty CKP sensor FMI 8 • Abnormal frequency or pulse width or period • Erratic or intermittent signal from CKP sensor • Open in the CKP sensor • MIL illuminated • Yellow electronic malfunction lamp illuminated • Possible loss of engine power • Increased engine start time • Increased fuel consumption • Uneven cylinder balancing • Power loss • Smoke • Faulty CKP sensor harness • Faulty CKP sensor mounting