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Home >> Chevrolet >> 1986 >> Caprice Base, 5.0 H >> Repair and Diagnosis >> Engine Performance >> System >> 4.3L TBI Tests W/Codes >> ECM Trouble Code Definitions
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ECM Trouble Code Definitions

ECM TROUBLE CODE DEFINITION (4.3L TBI)

Code No. Circuit Affected
12 (1) No RPM reference pulse.
13 Open oxygen sensor circuit.
14 Coolant sensor circuit shorted.
15 Coolant sensor circuit open.
21 TPS signal voltage high.
22 TPS signal voltage low.
24 VSS circuit.
32 EGR system failure.
33 MAP sensor signal voltage high.
34 MAP sensor signal voltage low.
42 EST circuit open or grounded.
43 Electronic Spark Control (ESC).
44 Lean oxygen sensor value.
45 Rich oxygen sensor value.
51 Faulty PROM, MEM-CAL or ECM.
52 Faulty/missing CALPAC or MEM-CAL.
54 Fuel pump voltage low.
55 Faulty ECM.
(1) Code "12" should be displayed only when no reference pulses are received by ECM (engine not running).
NOTE: Trouble code charts should only be used if "SERVICE ENGINE SOON" light is illuminated (indicating a current problem exists). Exceptions are Code 13, 15, 24, 44 and 45 charts, which may be used to help diagnose intermittent codes.
NOTE: Any time Codes 51, 52, 54 or 55 are displayed with another code, start with "50-series" code first, then proceed to low profile numbered code.
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