Powertrain Management: Testing and Inspection

TROUBLESHOOTING










Fault Diagnosis Function
- While the starter switch is in the ON position, the fault diagnosis function continuously monitors relevant sensors for faults.

- In the event that a fault is detected, the function illuminates a warning lamp (red or orange) in the meter cluster to alert the driver, memorizes the location of the fault, and switches to a backup mode.

- The memorized fault location can be read as a diagnosis code using an MUT-II or the diagnosis switch.

Warning lamp illumination







CAUTIONS:
- The fault diagnosis function requires a battery voltage of 12 V or higher.
- In the event of fault detection, check the harnesses and connectors for looseness. Before undoing any connector, turn the starter switch to the LOCK position and wait for 20 seconds.
- After rectifying a fault, delete the fault code using the MUT-II or memory clear switch.
- As a general rule, inspections should be performed with the starter switch in the LOCK position. If any inspection requires that the starter switch be in the ON position, be careful to avoid short circuits between connector terminals and with the vehicle body.
- All component resistances shown in this manual assume a temperature range of 10 to 35 °C {50 to 95 °F}. In practice, component values may not comply with standard values owing to temperature effects and/or to inaccuracy in the test instrument.
- After the rectification of a fault, the system's ability to return to normal operation automatically depends upon the diagnosis code, i.e., the fault location. When the system returns to normal operation, the warning lamp goes out.
- When the system returns to normal operation after the rectification of a fault, the diagnosis code remains stored in electronic governor control unit.

Inspection Procedure
Inspection of the electronic governor and pre-stroke control injection pump system can be performed most effectively using an MUT-II. Types of system inspection can, in accordance with fault systems and diagnosis codes, be broadly classified as follows:
- Inspections based on diagnosis codes stored in the control unit
- Inspections based on symptoms
- Inspections of intermittent faults