Important Preliminary Checks
Important Preliminary
  Checks 
 | Action 
 | 
Before performing Symptom diagnosis 
 | Before performing
  Symptom based diagnosis you must perform the 
Diagnostic System Check - Alternative Fuels (Engine Controls) 
. 
The System Check will determine the following: 
- The control modules - Alternative Fuels ECM and the gasoline
VCM  / PCM or ECM - and the MIL are operating correctly.
 
- There are no DTCs stored.
 
- Scan tool data is within normal operating range.
 
 
Several of the Symptom diagnostic tables require that a Visual and Physical
  Check be performed. Always perform a  Visual and Physical Check before using
             a Symptom diagnostic table. 
 | 
Visual and Physical Checks 
 | 
|     •  | Inspect the control modules (AF ECM and VCM / ECM or PCM) ground
 connections for being clean, tight and in the correct location. |  
  
|     •  | Inspect the gasoline control module (VCM/PCM or ECM) for the correct
 Bi-fuel calibration. Program the gasoline control module if necessary. |  
  
|     •  | Inspect the vacuum hoses for leaks, restrictions and proper connection
 as shown on the vehicle emission control information (VECI) label. |  
  
|     •  | Inspect for any type of fuel leak or fuel line restriction. |  
  
|     •  | Inspect for air leaks at all areas of the intake manifold sealing
 surfaces. |  
  
|     •  | Inspect for proper installation of the bonnet and mixer. |  
  
|     •  | Inspect for air leaks at the mixer. |  
  
|     •  | Inspect the ignition wires for the following conditions: |  
  
|     •  | Inspect vehicle wiring for the following: |  
  
 | 
Symptoms 
 | 
- Verify the customer concern.
 
- Locate the Symptom table that indicates the customers concern.
 
- Test or Inspect for the items indicated for that symptom.
 
 
The following Symptom tables are located in this section: 
 |