Important Preliminary Checks
| Action
|
Before performing Symptom diagnosis
| Before performing
Symptom based diagnosis you must perform the
Alternative Fuels (AF) Powertrain On Board (OBD) System Check
.
The OBD system check will determine the following:
| • | The control modules (AF ECU and VCM/PCM or ECM) and the MIL are
operating correctly. |
| • | There are no DTCs stored. |
| • | Scan tool data is within normal operating range. Refer to Typical
Scan tool Data Values. |
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
|
| • | Verify that the control modules' (AF ECU and VCM/ECM or PCM) ground
connections are 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. |
| • | Check the vacuum hoses for leaks, restrictions, and proper connection
as shown on the vehicle emission control information (VECI) label. |
| • | Check for any type of fuel leak or fuel line restriction. |
| • | Check for air leaks at all areas of the intake manifold sealing
surfaces. |
| • | Check for proper installation of the gas distribution adaptor
(GDA). |
| • | Check for air leaks at the GDA. |
| • | Check the ignition wires for the following conditions: |
| • | Check vehicle wiring for the following: |
|
Symptoms
|
- Verify the customer concern.
- Locate the Symptom table that indicates the customer's concern.
- Check the items indicated for that symptom.
The following Symptom tables are located in this section:
|
