DIAGNOSTIC TROUBLE CODE DEFINITIONS ⁽¹⁾

Code

Description

System Normal

Oxygen Sensor Circuit

Coolant Temperature Sensor (CTS) Indication Low

Coolant Temperature Sensor (CTS) Indication High

Throttle Position Sensor Circuit Indication High

Throttle Position Sensor Circuit Indication Low

Air Temperature Sensor (ATS) Circuit Indication Low

Air Temperature Sensor (ATS) Circuit Indication High

Pressure Sensor (PS) Circuit Voltage High

Pressure Sensor (PS) Circuit Voltage Low

No Ignition Signal

42 ⁽²⁾

Gear Position (5Th Switch) Circuit Grounded (M/T)

42 ⁽²⁾

Lock-Up Signal Continuous Input (A/T)

44 ⁽³⁾

Idle Switch Circuit Open Or Misadjusted

45 ⁽³⁾

Idle Switch Circuit Open Or Misadjusted

51 ⁽⁴⁾

EGR System Circuit Check

53 ⁽⁴⁾

ECM Ground Circuit Check

⁽¹⁾	Two types of ECM's are used. ECM is marked with or without "D" mark printed on ECM label. ECM with "D" mark is only used on initial production models only.

⁽²⁾	On Federal and Canadian models with "D" mark on ECM, when code occurs, ECM will not activate CHECK ENGINE light while engine is running. When problem is fixed, memory of defective area will automatically be erased from ECM.

⁽³⁾	On California models without "D" mark on ECM, when code occurs, ECM will not activate CHECK ENGINE light while engine is running. When problem is fixed, memory of defective area will automatically be erased from ECM.

⁽⁴⁾	Applicable to California models only.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Diagnostic Trouble Code Definitions