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Technical Forum (Read Only) => Computers, Fuel and Emissions => Topic started by: Irish_Alley on December 22, 2014, 08:33:32 AM

Title: Obd1 code retrieval and decoding/troubleshooting
Post by: Irish_Alley on December 22, 2014, 08:33:32 AM: 1. Jump terminals A and B (see diagram below) with the ignition "ON" and engine off. This will start the diagnostic mode. The computer will display a Code 12, three times, by flashing the check engine light. A Code 12 consists of one flash, a short pause, then two flashes three times.

2. Codes will be displayed by flashing the check engine light. All codes are displayed 3 times each then a code 12 will repeat and the trouble codes will start again.

(http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=29949.0;attach=36780;image)

code - code definition
12- diagnostic mode
13- 02 sensor or circuit (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316564#msg316564)
14- coolant sensor or circuit/ high temp indicated (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316565#msg316565)
15- coolant sensor or circuit/ low temp indicated (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316566#msg316566)
16- system voltage out of range
19- crankshaft position sensor or circuit
21- throttle position sensor or circuit- voltage high (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316567#msg316567)
22- throttle position sensor or circuit- voltage low (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316568#msg316568)
23- mixture control (m/c) solenoid or circuit (carbureted models)
23- manifold air temperature (mat) sensor or circuit (1990 and earlier models) (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316569#msg316569)
23- intake air temperature (iat) sensor circuit (fuel-injected models)
24- vehicle speed sensor (vss) or circuit (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316570#msg316570)
25- manifold air temperature (mat) sensor or circuit - high temperature indicated (1990 and earlier models) (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316571#msg316571)
25- intake air temperature (iat) sensor or circuit - high temperature indicated (1991 and later models)
26- quad driver module circuit
27- quad driver module circuit
28- quad driver module circuit
29- quad driver module circuit
31- park/neutral position (pnp) switch circuit
32- baro sensor or circuit (carbureted models)
32- egr circuit (fuel-injected models) (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316572#msg316572)
33- manifold absolute pressure (map sensor signal voltage high (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316573#msg316573)
33- mass air flow (maf) sensor or circuit - excessive airflow indicated
34- manifold absolute pressure (map) sensor signal voltage low (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316574#msg316574)
34- mass air flow (maf) sensor signal - low airflow indicated
35- idle speed control (isc) switch or circuit (shorted) (carbureted models)
35- idle air control (iac) valve/ circuit 38- brake switch circuit
39- torque converter clutch (tcc) circuit
41- no distributor signals to ecm, or faulty ignition module ( carbed models)
41- cylinders select error- mem-cal or ecm problem ( fuel-injected models
41- cam sensor circuit (3.8 engine)
42- bypass or electronic spark timing (est) circuit (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316574#msg316574)
43- low voltage at ecm terminal l (carbureted models)
43- knock sensor circuit
43-electronic spark control (ECS) circuit (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316576#msg316576)
44- oxygen sensor or circuit - lean exhaust detected (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316577#msg316577)
45- oxygen sensor or circuit - rich exhaust detected (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316578#msg316578)
46- power steering pressure switch circuit
48- misfire diagnosis
51- prom, mem-cal or ecm problem (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316579#msg316579)
52- calpak or ecm problem (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316579#msg316579)
53- egr fault (carburetor models only)
53- system over-voltage (ecm over 17.7 volts)
53- vehicle anti-theft system (vats) circuit (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316580#msg316580)
54- mixture control (m/c) solenoid or circuit (carburetor models)
54- fuel pump circuit (1986 and later models) (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51524;image)
55- oxygen sensor circuit or ecm
55- fuel lean monitor (2.2l engine) (http://forum.73-87chevytrucks.com/smforum/index.php?topic=29949.msg316579#msg316579)
61- oxygen sensor signal faulty (possible contaminated sensor)
62- transaxle gear switch signal circuits
63- manifold absolute pressure (map) sensor voltage high (low vacuum detected)
64- manifold absolute pressure (map) sensor voltage low (high vacuum detected)
66- pressure sensor or circuit air conditioning
Title: Code 13
Post by: Irish_Alley on January 09, 2020, 09:30:29 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51507;image)
Title: Code 14
Post by: Irish_Alley on January 09, 2020, 09:31:45 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51508;image)
Title: Code 15
Post by: Irish_Alley on January 09, 2020, 09:32:29 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51509;image)
Title: Code 21
Post by: Irish_Alley on January 09, 2020, 09:33:38 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51510;image)
Title: Code 22
Post by: Irish_Alley on January 09, 2020, 09:35:03 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51511;image)
Title: Code 23
Post by: Irish_Alley on January 09, 2020, 09:35:37 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51512;image)
Title: Code 24
Post by: Irish_Alley on January 09, 2020, 09:36:30 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51513;image)
Title: Code 25
Post by: Irish_Alley on January 09, 2020, 09:37:11 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51514;image)
Title: Code 32
Post by: Irish_Alley on January 09, 2020, 09:38:17 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51515;image)
Title: Code 33
Post by: Irish_Alley on January 09, 2020, 09:38:53 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51516;image)
Title: Code 34
Post by: Irish_Alley on January 09, 2020, 09:39:19 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51517;image)
Title: Code 42
Post by: Irish_Alley on January 09, 2020, 09:39:59 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51518;image)
Title: Code 43
Post by: Irish_Alley on January 09, 2020, 09:40:35 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51519;image)
Title: Code 44
Post by: Irish_Alley on January 09, 2020, 09:41:20 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51520;image)
Title: Code 45
Post by: Irish_Alley on January 09, 2020, 09:41:44 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51521;image)
Title: Code 51 52 55
Post by: Irish_Alley on January 09, 2020, 09:42:11 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51522;image)
Title: Code 53
Post by: Irish_Alley on January 09, 2020, 09:43:58 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51523;image)
Title: Code 54
Post by: Irish_Alley on January 09, 2020, 09:44:18 PM: (http://forum.73-87chevytrucks.com/smforum/index.php?action=dlattach;topic=37379.0;attach=51524;image)