NOTE: Trouble codes may also be referred to as DTC(s) or codes. Codes can also be retrieved using a scan tester.

The CHECK ENGINE light will come on when ignition is on and engine is not running. When engine is started, CHECK ENGINE light should go off. If light remains on while engine is running, a trouble code is present.
If light did not come on with key on and engine off, the CHECK ENGINE light circuit must be checked before continuing. See DIAGNOSTIC CIRCUIT CHECK under CODE CHARTS. Circuit checks are located with code charts.
To retrieve codes, install jumper wire between terminals No. 1 and No. 3 of ALDL connector located behind passenger's side kick panel. See Fig 1 .

Fig 1: Assembly Line Data Link (ALDL) Connector Terminal ID
Courtesy of ISUZU MOTOR CO.
Turn ignition on and count number of flashes from CHECK ENGINE light. All codes will be repeated 3 times. See Fig 2 . Each additional code will flash 3 times starting with lowest code to the highest.
If system is operating properly (with no trouble codes present), a Code 12 should be displayed with ignition on and engine off. This indicates the diagnostic system is capable of storing codes.
Each individual code will be repeated 3 times and then display the next code. See Fig 2 . Once all codes are displayed, codes will be repeated. Remove jumper wire from ALDL connector after codes have been retrieved.

Fig 2: Code Display (Typical)

Courtesy of ISUZU MOTOR CO.

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

Retrieving Codes