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Engine Controls - Tests W/codes - Transmission: Overview Chevrolet Pickup K1500

Testing & Diagnostics ~213 words

TROUBLE CODE IDENTIFICATION

Note. Trouble codes retrieved from PCM/TCM may be related to either engine or transmission. Transmission-related codes are covered in this article. For engine-related codes, see appropriate TESTS W/CODES article in the ENGINE PERFORMANCE Section. See TROUBLE CODE IDENTIFICATION table to determine if code is transmission or engine related.

  1. The system codes indicate failure of a specific sensor and/or circuit. Sensor/circuit diagnosis may indicate replacement of the control module. Code 51 indicates PROM/MEM-CAL is installed improperly or has failed.
  2. Code 55 indicates PCM/TCM has failed (except on 3.8L) and must be replaced. If the condition is still not corrected after replacing PCM/TCM, the cause may be as follows. An incorrect PCM/TCM or PROM/MEM-CAL application may cause a malfunction, which may or may not set a code. The PCM/TCM connector may be the problem. Connector terminals may have to be removed from the connector to be properly checked. PROM/MEM-CAL failure. Although the PROM/MEM-CAL rarely fails, it could be the cause of the problem. Replacement PCM/TCM may be faulty. Intermittent problem. Make a careful physical inspection of affected sensor/circuit. A shorted solenoid, relay, or harness may be the cause of PCM/TCM failure. Use Short Circuit Tester (J-34636) to check for short circuits.
CodeProbable Cause
12(1) No Engine Speed Sensor Reference Pulse To PCM/TCM
13(1) Open Oxygen Sensor Circuit
14(1) CTS Voltage Low (Sensor Or Signal Line Grounded)
15(1) CTS Voltage High (Sensor Or Signal Line Open)
16(1) System Voltage High/Low (3.8L) (2) Transmission Speed Error
17(1) RPM Signal Problem (3.8L)
18(1) Cam/Crank Error (3.8L)
21(1) TPS Voltage High (Open Circuit Or Misadjusted TPS)
22(1) TPS Voltage Low (Circuit Grounded)
23(1) Intake Air Temperature Sensor Voltage High
24(3) Vehicle Speed Sensor Circuit Open Or Grounded
25(1) Intake Air Temperature Sensor Voltage Low
26(1) Quad-Driver "A" Fault (3.8L) Quad-Driver 1 Fault (4.3L M/T "S" & "T" Pickup)
27(1) Quad-Driver 2 Fault (4.3L M/T "S" & "T" Pickup)
28(4) Pressure Switch Manifold Fault
31(1) Park/Neutral Switch Circuit (3.8L)
31(1) Turbocharger Wastegate Overboost (4.3L Turbo)
31(1) Engine Speed Control Governor (5.7L "G" Van)
31(5) MAP Voltage Low (Diesel)
31(1) Turbocharger Wastegate Overboost (4.3L Turbo)
32(1) EGR Error (Improper Vacuum Signal)
33(1) MAP Voltage High (Circuit Open Or Short To Voltage)
34(1) MAP Voltage Low (Circuit Open Or Short To Ground)
34(1) MAF Sensor Signal Voltage Low (3.8L)
35(1) IAC System Fault
36(1) Shift Control Problem (3.8L)
37(4) Brake Switch Stuck On (4L60-E)
38(1) Brake Switch Circuit (3.8L) Knock Sensor Circuit Open (4.3L M/T "S" & "T" Pickup) (4) Brake Switch Stuck Off (4L60-E)
39TCC Stuck Off ( (1) 3.8L & (4) 4L80-E)
39(1) Knock Sensor Circuit Shorted (4.3L M/T "S" & "T" Pickup)
41(1) Cam Sensor Circuit (3.8L)
42(1) EST Circuit Fault
43(1) ESC Fault
44(1) Lean Exhaust Indicated
45(1) Rich Exhaust Indicated
51(1) Improperly Installed/Faulty PROM/MEM-CAL
52(4) Long System Voltage High (4L60-E) (1) Fuel CALPAC Missing
53(3) System Voltage High (Charging System Problem)
53, 54 & 55(1) EGR Fault (3.8L)
54(1) Fuel Pump Circuit Voltage Low
55(1) Faulty ECM/PCM
56(1) Quad-Driver "B" Fault (3.8L)
58(4) TTS High Temperature (Sensor Or Signal Line Grounded)
59(4) TTS Low Temperature (Sensor, Connections Or Wires Open)
61(1) Cruise Vent Solenoid (3.8L)
62(1) Cruise Vacuum Solenoid (3.8L)
63(1) Cruise System Problem (3.8L)
65(1) Cruise Servo Position (3.8L)
66(1) Low A/C Refrigerant Charge (3.8L)
66(4) 3-2 Control Solenoid Fault (4L60-E)
67(4) TCC Solenoid Circuit Fault (4L60-E) (1) Cruise Engage Switches (3.8L)
68(4) Overdrive Ratio Error
68(Engine RPM Greater Than Input Speed)
68(1) Cruise System Problem (3.8L)
69(4) Torque Converter Stuck On (4L60-E) (1) A/C Head Pressure Switch (3.8L)
72(4) VSS Signal Loss (4L60-E)
73(4) Force Motor (Pressure Control Solenoid) Error
75(4) System Voltage Low (Charging System Problem)
79(4) Transmission Fluid Temperature High (4L60-E)
81(4) Solenoid "B" (2nd-3rd) Circuit Fault
82(4) Solenoid "A" (1st-2nd) Circuit Fault
83(4) TCC Solenoid Circuit Fault (4L80-E)
85(4) Undefined Gear Ratio (4L80-E)
86(4) Low Gear Ratio (4L80-E)
87(4) High Gear Ratio (4L80-E)
(1) Gasoline engine code. See appropriate TESTS W/CODES article in this section. (2) Models equipped with 4L60-E transmission, and 4.3L "S" and "T" series utility vehicles with man. trans. (3) Common gasoline engine and transmission code. See appropriate TESTS W/CODES article in this section. (4) Transmission code. Covered in this article. (5) Diesel engine code. For diesel code diagnosis, see G - DIESEL TESTS W/ CODES article in this section.
(1)Gasoline engine code. See appropriate TESTS W/CODES article in this section.
(2)Models equipped with 4L60-E transmission, and 4.3L "S" and "T" series utility vehicles with man. trans.
(3)Common gasoline engine and transmission code. See appropriate TESTS W/CODES article in this section.
(4)Transmission code. Covered in this article.
(5)Diesel engine code. For diesel code diagnosis, see G - DIESEL TESTS W/ CODES article in this section.

TROUBLE CODE IDENTIFICATION

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