Electronic Spark Timing (EST) (Impulse & Trooper 2.8L)

1. To check system operation, check timing at 1500 RPM. The Assembly Line Diagnostic Link (ALDL) connector must be grounded with engine at 1500 RPM.
2. The ALDL is located behind right side of instrument panel (Impulse) or below center console (Trooper). See Fig 1 and Fig 2 . On Impulse, install jumper wire between terminals "A" and "C" of ALDL connector. See Fig 1 . On Trooper, install jumper wire between terminals "A" and "B" of ALDL connector. See Fig 2 .
3. Note timing at 1500 RPM. If timing changed, system is operating correctly.

NOTE: If a problem develops with EST, ECM will set a Code 42. For additional testing procedures, see appropriate TESTS W/CODES article.

Fig 1: Grounding ALDL Connector (Impulse)

Courtesy of ISUZU MOTOR CO.

Fig 2: Grounding ALDL Connector (Trooper 2.8L)

Courtesy of ISUZU MOTOR CO.