FixVault

Tachometer Test

WARNING: This page is about a different car, the 1994 Buick Skylark. However, it is still accessible from the selected car via links, so may be relevant.
  1. Disconnect Electronic Ignition (EI) connector (V6) or Engine Control Module (ECM) connector C2 (4-cylinder). Plug Instrument Panel Cluster Tester (J 33431) into wall outlet. Connect tester 10-harness connector between tester to EI system connector terminal "C" or ECM connector C2 terminal B11 (White wire). Set tester controls to ON, 60 Hz, and 54 MPH.
  2. If tachometer reads 1800 RPM (4-cylinder) or 1350 RPM (V6), check for clean and tight connections at EI or ECM. If connections are okay, replace EI or ECM. If tachometer does not read 1800 RPM (4-cylinder) or 1350 RPM (V6), check White wire for and open or short circuit to ground. If wire is okay, replace IPC.