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Software Issue DBC4070 - Newly Released

JDS-62

Software Issue DBC 4070

MODEL:
Sedan Range

DATE:
3/93

JDS Software Issue DBC 4070 has been released and was recently shipped to all dealers. Software issue 4070 is to be used to diagnose faults on post-VIN 673299 sedan range vehicles, including 4.0 liter and 6.0 liter XJ12 models.

XJ12 Fuelling

A new 36 CU control module is introduced for XJ12 fuelling. This provides adaptive idle and two new fault codes which are as follows:

New Code Definition

67 Air Injection Failure

77 Loss of Engine Speed Signal

XJ12 Ignition

The air temperature switch and the coolant temperature sensor have been replaced with a single air temperature sensor, located in the left-hand air inlet elbow. In addition, the introduction of a gear shift retard function causes the ignition to retard during gearshifts in order to improve shift quality.

Automatic Transmission

The XJ12 is equipped with a new electronically controlled four speed automatic transmission, the GM 4L80-E.

Transmission diagnostics remain the same as those used on the ZF electronically controlled transmission. JDS will extract the fault data from the transmission control module (TCM) and display it on the screen, highlighting permanent faults. any intermittent faults will be displayed but no further testing is performed against these codes.

Each permanent fault will be prioritized according to it's impact on the vehicle and JDS will use this information to determine the order of testing. When the cause of the highest priority fault has been located, JDS will request if the operator wishes to continue on to test the next fault.

If no permanent faults are stored in the TCM. JDS will perform a number of standard checks, including checking to ensure that the TCM can store and output fault information.

Instrument Pack Programming

Two new pieces of software have been added to the previous control module programming options. This includes fuel gauge and trip computer re-calibration.

Ride Levelling

Software Issue 4070 has been improved to reduce the number of instances of incorrect diagnosis of the ride levelling system.

Connector Changes

The remainder of the software includes additional minor improvements, such as a reduction in the time required to perform a clear test on the A/C system. In addition, a large number of connectors have been changed (i.e. type, pin configuration or location) resulting in software modifications.