JDS Software - Issue DBC4065
JDS-63JDS Software Issue DBC 4065 - Introduction
MODEL:
94 MY XJS
DATE:
6/93
Software issue DBC 4065 should be used for diagnosing the 1994 MY XJS range from VIN 188105.
DBC 4065 blends the logic routines used in previous issues of JDS software. For example, Sedan Range 4.0 liter and 6.0 liter V12 engine and transmission logic has been carried over from software issue DBC 4060 and 4070. Also, logic from DBC 4055 is carried over to diagnose vehicle systems of the 1994 MY XJS.
Serial communications (ISO) is used to interface with the Engine Management System Diagnostic Trouble Codes (DTC), security system and drivers seat memory control module. Fault menu selections other than Engine Management or Transmission should be used only after a permanent electrical fault has been confirmed.
Software issue DBC 4065 is comprised of 3 discs, A, B & C. When using software issue 4065, all diagnostics must begin with disc A. From disc A, the user will be instructed to use discs B and C, if required.
Disc Contents:
Disc A:
^ MFU (Multi-function unit) includes HRW, interior lights, audible warnings
^ Heated seats
^ V12 EMS diagnostics
^ V12 Engine set-up
Disc B:
^ AJ6 EMS diagnostics
^ AJ6 Engine set-up
^ Cruise control
^ V12 Automatic transmission
^ 4.0L Automatic transmission
^ Gearshift/Key interlock
^ Power top
^ Trip computer
^ V12 Marelli ignition
^ Wash/wipe
^ Electric windows
Disc C:
^ Air conditioning
^ Central door locking
^ Security system
^ Seat/mirror circuits
^ Non-memory seats
^ Teves ABS
Connector Information, Multimeter Mode, Disc Check and Reload From New Disc options are available on all three discs.
New Features of JDS Issue DBC 4065
Bar Graph and Digital Display:
Previous JDS software issues display a bar graph during engine management, engine set-up and transmission set-up procedures. DBC 4065 will enhance this display by providing a digital display in addition to the bar graph.
Diagnosis to the Individual Wire:
Diagnosis to the individual wire is now available on all electrical systems covered by issue DBC 4065. Typical fault descriptions, see illustration.
The fault description is based upon the comparison of the last measurement to a previous measurement which was acceptable. The WK wire has open at pin 1. The open could be anywhere along the WK wire from the last known good reading. Circuit wiring diagrams should be used at this point to trace out the WK wire.
See illustration.
The fault description is based upon comparing the male to female side of a connector for the proper reading. The connector should be separated and inspected for pin and wire damage. See illustration.
The fault description indicates a short to ground somewhere along the WK wire from RB 55 pin 1. This conclusion is based upon the fact that some voltage is being sensed in the wire, however the value is low enough to indicate a short to ground. See illustration.
Fault description indicates a short to power supply somewhere along the WK wire from RB 55 pin 1. This conclusion is based upon the fact that high voltage is being sensed in the wire when it should either be open or grounded. The fault indicates two or more bare wires are making contact.
FAULT DIAGNOSTICS:
Fault Diagnostics provides 7 system selections enabling complete electrical system diagnosis. All diagnostics must begin with disc A of the 3 disc set.
VEHICLE SET-UP:
This is divided into 3 categories:
1) V12 Engine Set-Up
2) AJ6 Engine Set-Up
3) Security Set-Up
Engine Set-Up Menu
FULL SET-UP ensures that the engine idle speed, throttle potentiometer, oxygen sensor feedback system, and air injection system (AJ6) and kickdown switch are functioning properly and are correctly adjusted.
INDIVIDUAL CHECKS allows the operator to choose a single option for set-up, adjustment, and verification. Included are throttle potentiometer, oxygen sensor signals, engine idle speed, secondary air injection and exhaust gas recirculation (AJ6).
Security system set-up
This allows the operator to enable or disable security system options depending upon model variant and option level.
Connector Information:
Connector Information allows the technician access to vehicle connector information located on the vehicle through the JDS system.
Note:
When viewing connector information, [EXIT] allows the operator to return to the previous screen.
Multimeter Mode:
Allows JDS to operate as a multimeter when not in use for diagnostic purposes.
Disc Check:
Provides a quick check of the information stored on the software disc, to ensure software damage has not occurred.
Re-load From New Disc:
Permits disc transfer without turning off the machine.
Engine Management:
Tests the engine management electrical system and related harnesses. The test is initiated by serial communications (ISO) via POD 7 at the JD1 "CPC" connector. Permanent faults are traced to the lowest replaceable component by POD 7 and the technician. When an intermittent fault has been detected, the circuit is identified on the JDS screen and on the JDS printout. The circuit function is then checked for proper operation and the fault table cleared providing the fault has been repaired.
The 15 CU 4.0 Liter Engine Management system fitted to the 1994 MY is unchanged from the 1993 MY. Adaptive idle trim and improvements to the on-board diagnostic fault information are incorporated.
The 36 CU 6.0 Liter Engine Management system is new for 1994 MY XJS. It is similar to the XJ12 6.OL Sedan. Adaptive idle trim and improvements to the on-board diagnostic fault information are new to this engine.
When no DTC codes are present, the ECM will vary the injector ON time in a attempt to achieve a consistent (stoichiometric) fuel mixture. Feedback is observed through the heated oxygen sensor circuit. Normal idle speed is still controlled with the idle stepper motor (AJ6) or manual adjustment V12.
Adaptive Idle Trim:
This eliminates the need for idle adjustment of the mass air flow meter (MAFS) or EMS during the set-up procedure. This part of the set-up procedure is replaced with a test to ensure that the adaptive idle is operating properly.
Diagnostic Trouble Code (DTC) information through JDS has been enhanced with JDS Software Issue DBC 4065. This information will not appear on the OBD instrument display and can only be obtained with JDS. JDS records all of the fault information at its usual point in the diagnostic routine.
Gearshift and Key Interlock:
This tests the gearshift lock solenoid, key lock solenoid, brake electrical circuit, transmission rotary switch and associated harnesses.
Cruise Control:
Tests for electrical faults in the cruise control (speed control) system components and associated harness.
Trip Computer:
Tests the inputs, related components and harnesses to locate electrical faults in the trip computer system.
Interior Lighting:
Tests the lighting switches, relays, harnesses, and related components of the interior lighting circuit.
Air Conditioning:
Tests for electrical faults in the air conditioning system components and associated harness. The diagnostic routine is similar to DBC 4095.
JDS is not capable of testing climate control system calibration problems that may result in temperature drift, temperature variation between outlet ducts, or temperatures too hot or too cold for selected temperature setting. JDS should only be used for functional failure of the climate control electrical system after the vacuum, refrigerant and heater/cooling system are known to be operating properly.
Body Systems:
Diagnoses and verifies proper operation of all JDS related body and door electrical components.
Anti-Lock Braking:
Tests for electrical faults in all electrical components and associated harnesses of the ABS system. The ABS test is completed by "technician observation". Diagnosis is conducted via the ABS ECU. Analyzing the information, JDS decides upon a diagnostic routine.