top speed BMW 540i 1998 E39 User Guide

Downloaded from www.Manualslib.com manuals search engine
Brakes
Troubleshooting
Brake performance is mainly affected by three things:
Q Level and condition of brake fluid
Ability of bralte system to create and maintain pressure
Condition of friction components
Air in bralte fluid will
make the brake pedal feel spongy during
braking
orwill increase the bralte pedal force required to stop.
Fluid contaminated by moisture or dirt can corrode the sys-
tem. lnspect the brake fluid inside the reservoir. If it is dirty or
murky, or is more then two years old, replace fluid.
To
check the function of the master cylinder hold the bralte
pedal down hard with the engine running. If the pedal slowly
falls to the floor, either the master cylinder is leaking internal-
ly, or fluid is leaking externally.
lnspect the rotors for glazing, discoloration and scoring.
Steering wheel vibration while braking at speed is often
caused by warped rotors, but can also be caused by worn
suspension components.
When troubleshooting, keep in mind that tire inflation, wear
and temperature can all have an affect on braking. See
300
Suspension, Steering and Brakes-General for additional
suspension and brake system troubleshooting.
The table Brake system troubleshooting lists symptoms of
brake problems, probable causes, and suggested corrective
actions. Unless noted otherwise, relevant repairs are de-
scribed later in this repair group.

Downloaded from www.Manualslib.com manuals search engine
OBD-23
On-Board ~iagnostics]
I I
PI625 / 147 I Pedal Position Sensor Potentiometer Supply Channel 2 Electrical 1
Engine diagnostic trouble codes: M54 engine (continued)
P-code
BMW-FC Explanation
PI 604
PI604
PI619
PI620
PI624
PI632
PI633
PI634
P1 634
PI 634
PI 635
PI 636 50
51 123
123
146 i I
I
I Barometric Pressure Circuit Low
Control
Module Self-Test,
Speed Monitoring
Control Module Self-Test, Speed Monitoring
Map Cooling Thermostat Control Circuit Signal Low
Map Cooling Thermostat Control Circuit Signal High Pedal Position Sensor Potentiometer Supply Channel
1 Electrical (M52: Coolant Thermostat (Coolant
Temperature Below Thermostat Regulating Temperature))
115
115
115
135
136
115
109
PI639
PI675
PI694
P2088
P2089
P2090
P2091
I I
P2229 1197 I Barometric Pressure Circuit High
Throttle
Valve Adaptation Conditions Not Met
Throttle
Valve Adaptation Limp-Home Position Unknown
Throttle Valve Adaptation Spring Test Failed
Throttle
Valve Adaptation Spring Test Failed
Throttle
Valve Adaptation Spring Test Failed
Throttle Valve Adaptation Lower Mechanical Stop not Adapted
Throttle Valve Control Circuit
Throttle Valve Position Control, Control Deviation
PI 637
I I
P2270 1215 1 02 Sensor Signal Stuck Lean (Banic 1 Sensor 2)
PI 638 1160 I Throttle Valve Position Control Throttle Stucic Temporarily
162
161
135
136
21
21 19
19 Throttle
Valve Position Control Throttle
Stucic Permanently
Throttle Valve Actuator Start Test Re-Adaptation Required
Throttle Valve Actuator Start Test Spring Test and Limp-Home Position Failed
'A' Camshaft Position Actuator Control Circuit Low (Banlc 1)
'A' Camshaft Position Actuator Control Circuit High (Banlc 1)
'B' Camshaft Position Actuator Control Circuit Low (Bank 1)
'B' Camshaft Position Actuator Control Circuit High (Bank 1)
P2271
P2272
P2273
P3041
P3198 I I -
215
216
21 6
10481
10205 02
Sensor Signal Stucic Lean (Bank 1 Sensor 2)
02 Sensor Signal
Stuclc Lean (Bank 2 Sensor 2)
02 Sensor Signal Stuclc Lean (Bank 2 Sensor 2)
02 Sensor Lean and Rich Voltage Thresholds not Reached (Bank 2 Sensor 2)
Engine Coolant Temperature Gradient Too High
Engine Coolant Temperature Signal Stuck
P3199
P3238 1 10289 I Control Module Monitoring TPU Chip Defective
10207