Diagnostic Aids

Perform this circuit test when directed by other CIRCUIT TESTS. This test is only intended to diagnose:

• Throttle plate linkage.
• Test conditions.

1) Check For Codes 121, 122 & 123  Disconnect cruise control servo wiring harness connector (if equipped). Perform KOEO SELF-TEST. If Code 121, 122 or 123 is present, go to appropriate CIRCUIT TEST. See DIAGNOSTIC TROUBLE CODE REFERENCE CHART, and service codes as necessary. If Code 111 (pass code) is displayed, go to next step. If no code is displayed, go to CIRCUIT TEST QA.

2) Check Throttle Linkage  Check throttle and linkage for sticking and binding. If throttle and linkage are okay, replace Throttle Position (TP) sensor and repeat QUICK TEST. If throttle or linkage is binding, repair as necessary and repeat QUICK TEST.