Throttle position signal
 
  
 
 
  
  
   
   
    
     Output signal to automatic transmission
    
    
     Symptom of fault
    
   
   
    The CHECK ENGINE lamp (MIL) is on. The CHECK GEARBOX lamp is on. Diagnostic
trouble code in transmission control module (TCM).
    
    
    
     Conditions
    
   
   
    No diagnostic trouble code in the Trionic system.
    
    
    
     Diagnostic procedure
    
    
     1. Check the wiring
    
    
      
    
    
   
   
  
    
  
  
  
  
   
    
     
      | - | Check the lead between pin 57 of
the Trionic control module and pin 25 of the transmission control module for
continuity. 
 
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      | - | Check the lead for open circuit and
shorting. 
 
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   Is the lead OK?
  
  
  
   
    Continue with point 2.
    
    
   
  
  
  
  
   
    Rectify the fault and then continue with point 3.
    
    
   
  
  
  
   2. Check the output signal
  
  
    
  
  
  
  
   
    
     
      | - | Ignition switch in the OFF
position. 
 
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      | - | Plug in the Trionic control
module. 
 
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      | - | Remove the transmission control
module. 
 
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      | - | Ignition switch in ON
position. 
 
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      | - | Take a frequency reading across
pins 25 and 22 of the connector. 
 
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   The frequency should be 100 Hz.
   
   
   
    Frequency OK?
   
   
   
    
     Continue with point 3.
     
     
    
   
   
   
   
    
     Proceed to
     
       .
     
     .
     
     
    
   
   
   
    3. Final check
   
   
     
   
   
  
  
  
   
    
     
      | - | Clear the diagnostic trouble
code. 
 
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      | - | Implementation of driving cycle:
Drive the car at varying engine loads and rpm for 5 minutes. 
 
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      | - | Evaluation of driving cycle: Check
whether the diagnostic trouble code has recurred. 
 
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   Has the diagnostic trouble code recurred?
  
  
  
   
    Continue fault diagnosis as described in Service Manual 4:2 "Automatic
transmission".
    
    
   
  
  
  
  
   
    The remedial measure taken was correct.