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ECM Trouble Code Identification

ECM TROUBLE CODE IDENTIFICATION

Code Circuit Affected
12 (1) No Reference Pulse
13 Oxygen sensor circuit
14 Shorted coolant sensor circuit
15 Open coolant sensor circuit
21 TPS signal voltage high
23 M/C solenoid circuit open or grounded
34 Vacuum sensor circuit
41 No distributor reference pulses
42 EST circuit
44 Lean oxygen sensor value
45 Rich oxygen sensor value
51 Faulty PROM, PROM installation or ECM
54 Shorted M/C solenoid or faulty ECM
55 Faulty ECM (4.1L only)
(1) Code "12" displays only if no reference pulses are received by the ECM; it will never be stored as a malfunction.