Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2003 Jaguar XJRFACTORY OEM SERVICE PROCEDURE
Section 109 (Module Communications Network)
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Jaguar XKR, 2006 Jaguar XK8, 2005 Jaguar XKR, 2005 Jaguar XK8, and 2004 Jaguar XKR. However, it is still accessible from the selected car via links, so may be relevant.
- Module Communications Network
- Communications Network - Description & Operation
- Communications Network - Diagnostic Procedures
- Principles of Operation
- Inspection and Verification
- Driver Information Chart
- Default mode Definitions
- Diagnostic Trouble Code (DTC) index
- Power Supply/Ground test index
- Pinpoint Tests
- Pinpoint Test A: CHECK THE CONTROLLER AREA NETWORK FOR OPEN CIRCUIT
- Pinpoint Test B: CHECK THE CONTROLLER AREA NETWORK FOR SHORT CIRCUIT
- Pinpoint Test C: CHECK THE SCP NETWORK CIRCUIT
- Pinpoint Test : CHECK THE ISO NETWORK CIRCUIT
- Pinpoint Test E: DTC P1637; CHECK THE DSCCM SUPPLIES AND GROUNDS
- Pinpoint Test F: DTC P1643; CHECK THE TCM SUPPLIES AND GROUNDS
- Pinpoint Test G: DTC P1696; CHECK THE ASCCM SUPPLIES AND GROUNDS
- Pinpoint Test H: DTC P1699; CHECK THE A/CCM SUPPLIES AND GROUNDS
- Pinpoint Test I: DTC P1774; CHECK THE LINEAR SWITCH MODULE SUPPLIES AND GROUNDS
- Pinpoint Test J: DTC U1041 (CATS); VEHICLE SPEED SIGNAL FROM IC TO ADCM INVALID
- Pinpoint Test K: DTC U1041 (BPM); VEHICLE SPEED SCP MESSAGE INVALID
- Pinpoint Test L: DTC U1041 DDCM; VEHICLE SPEED SCP MESSAGE INVALID
- Pinpoint Test M: DTC U1041 (SLCM); VEHICLE SPEED SCP MESSAGE INVALID
- Pinpoint Test N: DTC U1135 (DDCM, DSCM, PDCM, PSCM, SLCM); IGNITION STATUS (IGNITION SWITCH POSITION) NOT OBTAINED
- Pinpoint Test O: DTC U1236 (A/CCM); CONTROL PANEL TO A/CCM SERIAL COMMUNICATION CIRCUIT FAULT
- Pinpoint Test P: DTC U1909 (DSCCM) LOCAL CAN NETWORK (STEERING ANGLE, SENSOR, YAW RATE, AND LATERAL ACCELERATION SENSOR) COMMUNICATIONS FAULT
- Pinpoint Test Q: DTC U2012 (BPM); KEY TRANSPONDER MODULE MESSAGE CORRUPT
- Pinpoint Test R: BPM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test S: SLCM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test T: PDCM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test U: DDCM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test V: PHRCM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test W: PSCM POWER SUPPLY FAULT
- Pinpoint Test X: DSCM POWER SUPPLY FAULT
- Pinpoint Test Y: DHRCM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test Z: MAJOR IC POWER SUPPLY OR GROUND FAULT
- Pinpoint Test AA: RCM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test AB: PACM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test AC: ADCM POWER SUPPLY OR GROUND FAULT
- Pinpoint Test AD: LEFT-HAND HID HEADLAMP POWER SUPPLY OR GROUND FAULT
- Pinpoint Test AE: RIGHT-HAND HID HEADLAMP POWER SUPPLY OR GROUND FAULT
- Pinpoint Test AF: KTM POWER SUPPLY OR GROUND FAULT
- Auxiliary Junction Box - Removal and Installation
- Battery Junction Box (BJB) - Removal and Installation
- Central Junction Box (CJB) LH - Removal and Installation
- Central Junction Box (CJB) RH - Removal and Installation
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.