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3-1-1 (Speedometer Signal Absent Or Faulty)

  1. Test drive vehicle. If speedometer does not operate, fault is not in ignition system. If speedometer operates during test drive, instrument cluster is receiving input signal. Activate diagnostic test mode No. 1 for instrument cluster (socket No. 7) and fuel injection system (socket No. 2). See DIAGNOSTIC TEST MODE NO. 1 under SELF-DIAGNOSTICS  . Display codes (if present).
  2. If speedometer signal is absent, and Codes 1-3-1 (instrument cluster) and 3-1-1 (fuel injection system) are present, wiring between instrument cluster, cruise control, and fuel injection and ignition systems is possibly open or shorted to ground or voltage.
  3. To check speed signal, connect measuring unit to ignition ECU. See MEASURING UNIT  under SELF-DIAGNOSTIC SYSTEM. Raise and support front wheels of vehicle. Turn ignition on. Connect voltmeter between measuring unit terminals No. 20 and 48. Spin front wheels. Voltage should vary between 0-12 volts. If voltage is consistently high or low, check wiring for an open or short circuit. If no fault is present, replace ignition ECU.
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