CIRCUIT TEST KP - OCTANE ADJUST Diagnostic Aids Enter this test when directed by QUICK TEST. This test is only intended to diagnose: Harness circuits (SIG RTN and OCT ADJ). "Â Octane adjust shorting bar connector. "Â Purpose of Octane Adjust Shorting Bar is to provide optimum spark advance for fuel used. If engine detonates (spark knock), remove Octane Shorting Bar. This retards spark advance about 3-4 degrees. If engine continues to detonate, use fuel with a higher octane rating. Fig. 83: Octane Adjust Circuit TEST PINS NO. 18, 29 OR 44 (OCT ADJ) WIRE COLOR I.D.
1) Code 57/341 Code 57/431 indicates Octane Adjust Shorting Bar is not in place or OCT ADJ circuit is open. Turn ignition off. Inspect Octane Adjust in-line connector. If shorting bar has been removed, go to step 2). If shorting bar is in place, go to step 4). 2) Check For Modification Decal If vehicle has modification decal indicating OCT ADJ shorting bar was removed as a factory authorized procedure, testing is complete. If engine is detonating, go to TESTS W/O CODES article in this section. If vehicle does not have modification decal, go to step 3). 3) Check For Code 57/341 Replace OCT ADJ shorting bar. Perform KOEO SELF-TEST. If Code 57/341 is present, go to step 4). If code is not present, testing is complete. If driveability faults are present, go to TESTS W/O CODES article in this section. 4) Check Octane Adjust Circuit Continuity Continuity should exist from OCT ADJ circuit, through in-line connector and shorting bar, to SIG RTN circuit. Turn ignition off. Disconnect 60-pin PCM connector. Inspect terminals, and repair if damaged. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Measure resistance between test pin No. 46 and OCT ADJ test pin at breakout box. If resistance is more than 5 ohms, repair open OCT ADJ circuit, shorting bar or SIG RTN circuit. Repeat QUICK TEST. If resistance is 5 ohms or less, replace PCM and repeat QUICK TEST. 5) Check For Code 11/111 Start engine. Warm it to normal operating temperature. Turn ignition off. Perform KOEO SELF-TEST. If Code 11 or 111 is present, go to step 6). If Code 57/341 is present, return to step 1). For all other codes, return to QUICK TEST. 6) Verify In-Line Shorting Bar Is Installed Turn ignition off. Inspect Octane Adjust in-line connector. If shorting bar is installed, go to step 8). If shorting bar is not installed, go to step 7). 7) Check For Modification Decal If vehicle has modification decal indicating OCT ADJ shorting bar was removed as a factory authorized procedure, testing is complete. If engine is detonating, go to TESTS W/O CODES article in this section. If vehicle does not have modification decal, go to step 10).
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Thursday, May 7th, 2009 AT 4:20 PM
