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Service Throttle Soon Indicator Always On (Diesel)

  1. Disconnect Powertrain Control Module (PCM) harness connector. Turn ignition switch to RUN position. If indicator goes out, problem is in throttle control system. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If indicator remains lit, go to next step.
  2. Using test light, backprobe instrument cluster harness connector terminal No. 21 (White/Black wire) to battery power. If test light lights, repair short to ground in White/Black wire. If test light does not light, repair and/or replace instrument cluster.
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