Tachometer Inoperative On Models With Clean Tach Output (CTO) Only
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2002 Mercury Sable, 2002 Mercury Mountaineer, 2002 Mercury Grand Marquis, 2002 Mercury Cougar, and 2002 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
Check CTO circuit from PCM terminal No. 48. Go to TEST JH, step 1) under SYSTEM TESTS in SELF-DIAGNOSTICS - EEC-V - GASOLINE & NGV article. To determine if CTO circuit is used, see appropriate PIN VOLTAGE/PID VALUE CHARTS article. Check terminal No. 48 under OUTPUTS.