Symptom Checks

Check the following items:

• On models with Clean Tach Output (CTO) circuit at PCM pin No. 48, check CTO circuit from PCM. See TEST JH under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V (GASOLINE) article. To determine if CTO circuit is used, see appropriate PIN VOLTAGE/PID VALUE CHARTS article. Check pin No. 48 under OUTPUTS.
• Check instrumentation. See appropriate INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT.