Instructions For Using The Mechanical Diagnostic Form
The mechanical diagnostic form is intended to be the starting point for diagnostics for most engine related problems. It addresses diagnostic procedures for Hard Start/No Start conditions as well as Performance concerns. It is also intended to a be used as a diagnostic and warranty record for the vehicle.
Prior to removal and replacement of the parts listed below, it is required that the appropriate sections of the mechanical diagnostic form be completed to secure warranty reimbursement.
- Injectors (9E527)
- Injection control pressure regulator (9C968)
- High pressure pump assembly (9A543)
- Turbocharger/pedestal assembly (9350)
- Fuel pump (9350) Injector Drive Module (12B599)
- Powertrain control module (12A650)
Structure: The top of the form provides the technician with areas to enter data that will identify the customer, dealer, model year, engine and vehicle configuration and what the customer’s complaint is.
Customer Name: Required for warranty purposes.
Dealer Name and Location: Required for warranty purposes.
1863 Claim Number: Required for warranty purposes.
Date: Required for warranty purposes.
Model Year: Significant changes in PCM calibration and diagnostics have occurred between the 1994 and 1995 PCM calibration. Calibrations for 1994 utilize a STAR II tester and connect to the STI and STO connector located under the hood. PCM calibrations for 1995 utilize the NGS tool (New Generation Star Tester) which has an under dash connection and is capable of commanding diagnostic tests and monitoring PID’s on the diagnostic data link. Trucks built in 1995 do not have the under hood connector for the STAR II tester. Trucks built in 1994 have the connector under the dash for the NGS tool. The connector is not functional for diagnostics unless the PCM has been reflashed to a 1995 calibration. If a 1994 vehicle had been reflashed to a 1995 calibration, the STI and STO connector under the hood will not function with the STAR II tester.
Vehicle Serial Number: The tenth position of the vehicle serial number (VIN) indicates model year.
- R=1994
- S=1995
- T=1996
- V=1997
Engine Serial Number: The engine serial number is located on the calibration tag applied to the reservoir and also is stamped on the cylinder block on a pad located near the rear of the oil cooler.
Odometer: Required for warranty purposes.
Chassis Style: Helpful for evaluation of performance or fuel consumption complaints.
Vehicle GVW: Helpful for evaluation of performance or fuel consumption complaints.
Transmission: Helpful for evaluation of performance or fuel consumption complaints. Different PCM calibrations are required for manual and automatic transmissions.
Ambient Temperature: Glow plug on time and exhaust back pressure operation are dependent on ambient temperature.
Customer Complaints: Detailed description of customers concerns including conditions required to make the problem occur.
The left side of the form provides the technician with the procedures to diagnose a Hard Start/No Start complaint. Each test should be completed and the test values entered into each box.
The right side of the form provides the technician with the procedures to diagnose a performance complaint (examples listed below).
- Low Power
- Misfire/Rough Running
- Stalling
- Surging Smoke
Each test should be completed and the test values entered into each box.
The bottom of the form allows for entry of repairs performed to correct the problem, the names of the parts replaced, the part numbers replaced as well as the serial numbers of the defective items.
