Test KE - Introduction

NOTE: Perform this test when Code 12, 13, 16, 17, 19, 47 or 48 is displayed during QUICK TEST or when directed here by other test procedures. If engine is running rough or has rough idle, correct these conditions before performing test. Causes may be in ignition system, fuel system or EGR system. This test is intended to diagnose only the following:

RPM during Self-Test mode
ISC solenoid
Harness circuits (ISC and VPWR)
Faulty ECA
NOTE: To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault:
Engine temperature not up to operating temperature
Engine over operating temperature
A/C input (electrical problem)
Incorrect idle speed or throttle stop adjustment
Faulty cruise control linkage

Fig 1: Idle Speed Control (Air By-Pass) Circuit