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Home >> Chevrolet >> 1988 >> Spectrum Express >> Repair and Diagnosis >> Engine Performance >> System >> 1.5L EFI Turbo >> Trouble Shooting >> Component Testing By Trouble Code >> Code 31 (Turbocharger Wastegate Control)
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Code 31 (Turbocharger Wastegate Control)

  1. Clear codes. Disconnect hoses at turbocharger Vacuum Solenoid Valve (VSV) and air duct. Turn ignition on and blow air through VSV. If air passes through valve, check that VSV harness White wire and ECM harness connector B2 is not shorted to ground. If harness tests good, replace VSV.
  2. If air will not pass through VSV, jumper ALDL and turn ignition on. Blow air through VSV. If air will not pass through VSV, check circuit B2 for open or faulty ECM.
  3. If air will pass through VSV in step 2), check turbocharger wastegate valve diaphragm. If diaphragm is defective, replace turbocharger. If diaphragm tests good, check for clogged or defective hoses.