LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2018 >> Terrain SL >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel System Displays And Gauges >> Diagnostic Information And Procedures >> Tachometer Inaccurate Or Inoperative (With LVL, LH7, Or LWW) >> Circuit/System Testing

Circuit/System Testing

NOTE:

Circuit/System Verification must be performed before proceeding with Circuit/System Testing.

  1. Ignition OFF, disconnect the X1 harness connector at the A11 Radio.
  2. Ignition ON, test for 9 - 11 volts between the engine speed signal circuit terminal 23 and ground.
    • If less than 9 volts 
    1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the signal circuit terminal 44 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the A11 Radio.
    • If greater than 11 volts 
    1. Ignition OFF, disconnect the X3 harness connector at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit terminal 44 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the A11 Radio.
    • Go to next step: If 9 - 11 volts 
  3. Test or replace the K20 Engine Control Module.
scientia non olet · About LEMON Manuals