LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 1998 >> Prizm Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Circuit Tests >> Electrical Load Idle-Up Circuit >> Diagnosis & Repair
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM in TESTS W/CODES article. After performing OBD system check, go to next step.
  2. Install scan tool. Start and warm engine to normal operating temperature. Turn off all accessories. Using scan tool, monitor electrical load parameter while turning rear window defogger on and off. If engine RPM does not increase when switch is turned on, go to step 4). If engine RPM does increase, go to next step.
  3. Using scan tool, monitor electrical load parameter while turning parking lights on and off. If engine RPM does not increase when switch is turned on, go to step 5). If engine RPM does increase, system is functioning normally.
  4. Turn ignition off. Disconnect PCM electrical connectors. Check for an open or short in electrical load idle-up signal circuit between rear defogger switch and PCM. Repair as necessary. After repairs, go to step 7). If circuit is okay, go to step 6).
  5. Turn ignition off. Disconnect PCM electrical connectors. Check for an open or short in electrical load idle-up signal circuit between parking light switch and PCM. Repair as necessary. After repairs, go to step 7). If circuit is okay, go to next step.
  6. Replace PCM. After repairs, go to next step.
  7. After repairs are completed, operate vehicle within conditions under which original symptom was observed. If system operates properly, repair is complete. If system does not operate properly, go to DIAGNOSTIC AIDS.
scientia non olet · About LEMON Manuals