Defender. Manual - part 44
Anti-Lock Control - Traction Control - Anti-Lock Control - Traction Control
Diagnosis and Testing
Inspection and Verification
1. 1. Verify the customer concern.
2. 2. Visually inspect for obvious signs of mechanical or electrical damage.
3. 3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before
proceeding to the next step.
4. 4. If the cause is not visually evident, check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.
DTC index
• NOTE: If the control module/HCU is suspect and the vehicle remains under manufacturer warranty, refer to the
Warranty Policy and Procedures manual (section B1.2), or determine if any prior approval programme is in operation,
prior to the installation of a new module/HCU.
• NOTE: Generic scan tools may not read the codes listed, or may read only five digit codes. Match the five digits from
the scan tool to the first five digits of the seven digit code listed to identify the fault (the last two digits give additional
information read by the manufacturer approved diagnostic system).
• NOTE: When performing electrical voltage or resistance tests, always use a digital multimeter (DMM) accurate to three
decimal places, and with an up-to-date calibration certificate. When testing resistance, always take the resistance of the
DMM leads into account.
• NOTE: Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.
• NOTE: Inspect connectors for signs of water ingress, and pins for damage and/or corrosion.
• NOTE: If DTCs are recorded and, after performing the pinpoint tests, a fault is not present, an intermittent concern
may be the cause. Always check for loose connections and corroded terminals.
DTC Description
Possible cause
Action
12 Pump failure
1 - high
level at
C0504-8
without
pump
actuation
ABS pump
monitor circuit,
short circuit to
power
ABS pump
relay contacts
stuck closed
Refer to the electrical guides and check C0504-8 ABS pump monitor circuit for
short circuit to power. Check ABS pump relay for stuck closed contacts.
13 Pump failure
2 - low level
at C0504-8
during
pump
actuation
ABS pump
monitor circuit,
short circuit to
ground
ABS pump
relay fuse
failure
ABS pump
relay battery
supply circuit,
Open circuit
Check for ABS pump relay fuse failure. Refer to the electrical guides and check
C0504-8 ABS pump monitor circuit, for short circuit to ground. Check C0508-3
ABS pump relay battery supply circuit, for open circuit.
14 Pump failure
3 - pump
sticks
• NOTE: The ABS
pump is part of the
ABS modulator
assembly
Internal failure
ABS pump
Refer to the warranty policy and procedures manual if ABS pump/ABS
modulator is suspect.
15 Pump failure
4 - sticking
pump relay
ABS pump
relay coil
circuit, short
circuit to
power
ABS pump
relay contacts
stuck closed
ABS pump
relay fault
Refer to the electrical guides and check C0506-15 ABS pump relay coil circuit,
for short circuit to power. Check ABS pump relay for stuck closed contacts.
16 Failure of
• NOTE: The shuttle
Refer to the electrical guides and check resistance between C0506-3 reference