Reading Trouble Codes

The control module stores component failure information under a related trouble code which can be recalled for diagnosis and repair. Read trouble codes by counting Malfunction Indicator Light (MIL) flashes or with diagnostic scan tester connected to the Data Link Connector (DLC). The tester is faster, and capable of reading information which would require testing individual control module and sensor/solenoid connector terminals with a digital voltmeter. Some models REQUIRE a scan tester to pull trouble codes. See SCAN TESTER DATA and SCAN TESTER USAGE .

NOTE: When using a scan tester, there is a time delay between serial data updates. For instantaneous response, a digital voltmeter must be used.

If scan tester is not available, MIL flashes can be read by grounding DLC terminal with ignition on and engine off. For example, FLASH, FLASH, pause, FLASH, longer pause, indicates Code 21. The first series of flashes are the first digit of trouble code. The second series of flashes are the second digit of trouble code. Trouble codes are displayed starting with the lowest code. Each code is displayed 3 times and will continue as long as DLC is grounded.

NOTE: Trouble codes will be recorded at various operating times. Some codes require sensor or switch operation for 5 seconds and others may require longer under certain conditions. Some codes may not set in a service bay operational mode.

TROUBLE CODE IDENTIFICATION

Code

Probable Cause

CODE 13

Open Oxygen Sensor Circuit - ALL MODELS

CODE 14

Coolant Sensor Signal Voltage Low - All Models

CODE 15

Coolant Sensor Signal Voltage High - All Models

CODE 16

Vss Buffer Fault - "S" & "T" Series, (Vin W) Utility A/T & (Vin Z) Pickup A/T

CODE 21

Tps Signal Voltage High - All Models

CODE 22

Tps Signal Voltage Low - All Models

CODE 23

Intake Air Temp. Low - "L", "M", "S" & "T" Series

CODE 24

VSS Transmission Output Signal - A/T - All Models

CODE 25

Intake Air Temperature High - "L", "M", "S" & "T" Series

CODE 28

Transmission Range Pressure Switch - All Models

CODE 32

EGR Circuit Error Backpressure Egr With Solenoid - "C", "K" & "P" Series

CODE 32

EGR Circuit Error With Evrv Solenoid - "C", "G", "K" & "P" Series

CODE 32

EGR Circuit Error - "L", "M", "S" & "T" Series W/ Linear EGR

CODE 32

EGR Circuit Error - "C", "G" & "K" Series W/ Linear EGR

CODE 33

MAP Sensor Signal Voltage High - All Models

CODE 34

MAP Sensor Signal Voltage Low - All Models

CODE 35

Idle Speed Error - All Models

CODE 36

Idle Speed Actuator Fault - "C", "G", "K" & "P" Series A/T

CODES 37/38

TCC Brake Switch On/Off - All Models A/T

CODE 39

TCC Stuck Off - "C", "G", "K" & "P" Series With 4L80-E Transmission

CODE 42

Ignition Control - All Models

CODE 43

Knock Sensor W/O Spark Module (Dual Sensors)

CODE 43

Knock Sensor Without Spark Module (Single Sensor)

CODE 43

Knock Sensor With Spark Control Module "C", "K" & "P" Series

CODE 44

Lean Exhaust Indication - All Models

CODE 45

Rich Exhaust Indication - All Models

CODE 51

PROM Error (Faulty or Incorrect PROM)

CODE 52

Faulty CALPAK

CODE 52/53

System Voltage High - All Models

CODE 54

Fuel Pump Circuit - All Models

CODE 55

ECM/PCM Error

CODE 58

Transmission Fluid Temperature High - All Models

CODE 59

Transmission Fluid Temperature Low - All Models

CODE 66

3-2 Control Solenoid Ckt Fault 4L60-E Transmission

CODE 67

TCC Solenoid Circuit Check - 4L60-E Transmission

CODE 68

Overdrive Ratio Error - 4L80-E Transmission

CODE 69

Torque Converter Clutch Stuck On 4L60-E Transmission

CODE 69

Torque Converter Clutch Stuck On 4L80-E Transmission

CODE 72

VSS Circuit Loss Trans Output Signal - All Models

CODE 73

Pressure Control Solenoid (Current Error) - All Models

CODE 74

Transmission Input Speed Error 4L80-E Transmission

CODE 75

System Voltage Low - All Models

CODE 79

Transmission Fluid Temperature High - All Models

CODE 81

Transmission 2-3 Error - All Models

CODE 82

Transmission 1-2 Error - All Models

CODE 83

TCC Solenoid Circuit Fault - All Models

CODE 85

Undefined Gear Ratio - All Models

CODE 86

Low Gear Ratio Error - All Models

CODE 87

High Gear Ratio Error - All Models

CODE P0106 ⁽¹⁾

MAP Sensor Range Problem - "S" & "T" Series 4.3L (Vin W)

CODE P0107 ⁽¹⁾

MAP Sensor Ckt - "S" & "T" Series 4.3L (Vin W)

CODE P0108 ⁽¹⁾

MAP Sensor Ckt - "S" & "T" Series 4.3L (Vin W)

CODE P0112 ⁽¹⁾

IAT Sensor Circuit Low Input - "S" & "T" Series 4.3L (Vin W)

CODE P0113 ⁽¹⁾

IAT Sensor Circuit High Input - "S" & "T" Series 4.3L (Vin W)

CODE P0117 ⁽¹⁾

Coolant Temperature Sensor Temperature Low "S" & "T" Series 4.3L (Vin W)

CODE P0118 ⁽¹⁾

Coolant Temperature Sensor Temperature High "S" & "T" Series 4.3L (Vin W)

CODE P0121 ⁽¹⁾

Tp Sensor Range/Performance Problem "S" & "T" Series 4.3L (Vin W)

CODE P0122 ⁽¹⁾

Throttle Position Sensor Signal Low "S" & "T" Series 4.3L (Vin W)

CODE P0123 ⁽¹⁾

Throttle Position Sensor Signal High "S" & "T" Series 4.3L (Vin W)

CODE P0123 ⁽¹⁾

Throttle Position Sensor Signal High 4.3L "S" & "T" Series (Vin Z)

CODE P0125 ⁽¹⁾

Coolant Sensor Excessive Time To Closed Loop "S" & "T" Series 4.3L (Vin W)

CODE P0131 ⁽¹⁾

Heated Oxygen Sensor Low Signal Voltage (Lean) "S" & "T" Series 4.3L (Vin W)

CODE P0132 ⁽¹⁾

Heated O2 Sensor High Signal Voltage (Rich "S" & "T" Series 4.3L (VIN W) Bank 1, Sensor 1

CODE P0133 ⁽¹⁾

Heated Oxygen Sensor Slow Response

CODE P0134 ⁽¹⁾

Heated Oxygen Sensor Open Circuit - "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 1

CODE P0135 ⁽¹⁾

Heated Oxygen Sensor Heater Circuit Malfunction "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 1

CODE P0137 ⁽¹⁾

Heated Oxygen Sensor Low Signal Voltage (Lean) "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 2

CODE P0138 ⁽¹⁾

Heated Oxygen Sensor High Signal Voltage (Rich) "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 2

CODE P0139 ⁽²⁾

Heated Oxygen Sensor Open Circuit "S" & "T" Series 4.3L (Vin Z) Bank 1, Sensor 2

CODE P0140 ⁽¹⁾

Heated Oxygen Sensor Open Circuit "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 2

CODE P0141 ⁽¹⁾

Heated Oxygen Sensor Heater Circuit Malfunction "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 2

CODE P0171 ⁽¹⁾⁽²⁾

Fuel Trim Lean - "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 1

CODE P0171 ⁽¹⁾⁽²⁾

Lean Exhaust - "S" & "T" Series 4.3L (Vin Z)

CODE P0172 ⁽¹⁾⁽²⁾

Fuel Trim Rich - "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 1

CODE P0172 ⁽¹⁾⁽²⁾

Rich Exhaust - "S" & "T" Series 4.3L (Vin Z)

CODE P0300 ⁽¹⁾

Random Misfire Detected - "S" & "T" Series 4.3L (Vin W)

CODE P0301-306 ⁽¹⁾

Cylinders 1-6 Misfiring - "S" & "T" Series 4.3L (Vin W)

CODE P0320 ⁽²⁾

Ignition Control Error - "S" & "T" Series 4.3L (Vin Z)

CODE P0325/0326 ⁽¹⁾

Knock Sensor Open Or Shorted "S" & "T" Series 4.3L (Vin W)

CODE P0327 ⁽²⁾

Knock Sensor Grounded - "S" & "T" Series 4.3L (Vin Z)

CODE P0328 ⁽²⁾

Knock Sensor Open - "S" & "T" Series 4.3L (Vin Z)

CODE P0337/0338 ⁽¹⁾

Crank Sensor Input - "S" & "T" Series 4.3L (Vin W)

CODE P0340 ⁽¹⁾

Cam Sensor Malfunction - "S" & "T" Series 4.3L (Vin W)

CODE P0400 ⁽¹⁾

EGR Error - "S" & "T" Series 4.3L (Vin Z)

CODE P0401 ⁽¹⁾

EGR Flow Test Failure - "S" & "T" Series 4.3L (Vin W)

CODE P0420 ⁽¹⁾

Catalyst Efficiency Low (Bank 1)

CODE P0441 ⁽¹⁾

Incorrect EVAP Purge - "S" & "T" Series 4.3L (Vin W)

CODE P0500 ⁽¹⁾⁽²⁾

VSS Circuit - "S" & "T" Series

CODES P0502/0503 ⁽¹⁾

VSS Circuit Low/High - "S" & "T" Series 4.3L (Vin W)

CODE P0506/0507 ⁽¹⁾

IAC Counts Low/High - "S" & "T" Series 4.3L (Vin W)

CODE P0560 ⁽¹⁾

System Voltage Malfunction - "S" & "T" Series 4.3L (Vin W)

CODE P0703 ⁽¹⁾

TCC Brake Input Circuit "S" & "T" Series 4.3L (Vin W)

CODE P0712 ⁽¹⁾

Transaxle Temperature Sensor Signal Voltage Low "S" & "T" Series 4.3L (Vin W)

CODE P0713 ⁽¹⁾

Transaxle Temperature Sensor Signal Voltage High "S" & "T" Series 4.3L (Vin W)

CODE P0742 ⁽¹⁾

TCC Stuck On - "S" & "T" Series 4.3L (Vin W)

CODE P0748 ⁽¹⁾

Pressure Control Solenoid - "S" & "T" Series 4.3L (Vin W)

CODE P0753 ⁽¹⁾

1-2 Shift Solenoid - "S" & "T" Series 4.3L (Vin W)

CODE P0756 ⁽¹⁾

2-3 Shift Solenoid Performance - "S" & "T" Series 4.3L (Vin W)

CODE P0758 ⁽¹⁾

2-3 Shift Solenoid Electrical "S" & "T" Series 4.3L (Vin W)

CODE P1106 ⁽¹⁾

MAP Intermittent High - "S" & "T" Series 4.3L (Vin W)

CODE P1107 ⁽¹⁾

MAP Intermittent Low - "S" & "T" Series 4.3L (Vin W)

CODE P1111 ⁽¹⁾

IAT Intermittent High - "S" & "T" Series 4.3L (Vin W)

CODE P1112 ⁽¹⁾

IAT Intermittent Low - "S" & "T" Series 4.3L (Vin W)

CODE P1114 ⁽¹⁾

ECT Intermittent Low - "S" & "T" Series 4.3L (Vin W)

CODE P1115 ⁽¹⁾

ECT Intermittent High - "S" & "T" Series 4.3L (Vin W)

CODE P1121 ⁽¹⁾

TP Sensor Intermittent High - "S" & "T" Series 4.3L (Vin W)

CODE P1122 ⁽¹⁾

TP Sensor Intermittent Low - "S" & "T" Series 4.3L (Vin W)

CODE P1133 ⁽¹⁾

Oxygen Sensor Insufficient Activity "S" & "T" Series 4.3L (Vin W) Bank 1, Sensor 1

CODE P1221 ⁽¹⁾

Fuel Pump Secondary System Circuit Low "S" & "T" Series 4.3L (Vin W)

CODE P1222 ⁽²⁾

Fuel Pump Voltage Low - "S" & "T" Series 4.3L (Vin Z)

CODE P1345

Crankshaft/Camshaft Sensor Correlation Error "S" & "T" Series 4.3L (Vin W)

CODE P1351 ⁽¹⁾

EST Output High - "S" & "T" Series 4.3L (Vin W)

CODE P1361

EST Not Toggling - "S" & "T" Series 4.3L (Vin W)⁽²⁾

CODE P1406 ⁽¹⁾

EGR Valve Pintle Position - "S" & "T" Series 4.3L (Vin W) (1 Of 2)

CODE P1406 ⁽¹⁾

EGR Valve Pintle Position - "S" & "T" Series 4.3L (Vin W) (2 Of 2)

CODE P1441 ⁽¹⁾

Evaporative System Continuous Purge "S" & "T" Series 4.3L (Vin W)

CODE P1442 ⁽¹⁾

Evaporative System Vacuum Switch Static Test Malfunction - "S" & "T" Series 4.3L (Vin W)

CODE P1508/1509 ⁽²⁾

Idle Speed Low/High - "S" & "T" Series 4.3L (Vin W)

CODE P1632 ⁽¹⁾

System Voltage High - "S" & "T" Series 4.3L (Vin Z)

CODE P1810 ⁽¹⁾

Transmission Range Switch Assembly Circuit "S" & "T" Series 4.3L (Vin W)

CODE P1812 ⁽¹⁾

Trans Fluid Overtemp - "S" & "T" Series 4.3L (Vin W)

CODE P1860 ⁽¹⁾

TCC PWM Solenoid Electrical Circuit "S" & "T" Series 4.3L (Vin W)

CODE P1864 ⁽¹⁾

TCC Solenoid Electrical Circuit "S" & "T" Series 4.3L (Vin W)

CODE P1870 ⁽¹⁾

Transmission Component Slipping "S" & "T" Series 4.3L (Vin W)

CODE P1886 ⁽¹⁾

3-2 Solenoid Electrical Circuit "S" & "T" Series 4.3L (Vin W)

⁽¹⁾	4.3L (VIN W) "S" and "T" Series.

⁽²⁾	4.3L (VIN Z) "S" and "T" Series.

NOTE: On models not using "P" series codes, Code 12 should always exist when DLC test terminal is grounded with key on and engine off, but it may not be indicated by all makes of scan tester.