2001 BMW 525i Air sensor

Downloaded from www.Manualslib.com manuals search engine
- -
On-Board Diagnostics
Professional diagnostic scan tools available atthe time of this
printing include the BMW factory tools
(DISplus, GTI,
MoDiC) and a small number of aftermarket BMW-specific
tools. See
020 Maintenance.
In addition to the professional line of scan tools, inexpensive
generic OBD
II scan tool software programs and handheld
units are readily available. Though limited, they are
nonetheless powerful diagnostic tools. These tools read live
data streams and freeze frame data as well as a host of other
valuable diagnostic data.
Diagnostic monitors
Diagnostic monitors run tests and checks on specific
emission control systems, components, and functions.
A complete drive cycle is requiredforthe tests to bevalid. See
Drive cycle in this repair group. The diagnostic monitor
signals the
ECM of the loss or impairment of the signal or
component and determines if a signal or sensor is faulty
based on
3 conditions:
* Signal or component shorted to ground
Signal or component shorted to
B+
Signal or component missing (open circuit)
The OBD
II system monitors all emission control systems that
are installed. Emission control systems vary by vehicle model
and year. For example, a vehicle may not be equipped with
secondary air injection, so no secondary air readiness code
would be present.
OBD
II software monitors the following:
Oxygen sensors
Catalysts
Engine misfire
- Fuel tank evaporative control system
Secondary air injection Fuel system
Oxygen sensor monitoring. When driving conditions allow,
response rate and switching time of each oxygen sensor is
monitored. The oxygen sensor heater function is also
monitored. The OBD
II system differentiates between
precataylst and post-catalyst oxygen sensors and reads each
one individually. In order
forthe oxygen sensor to be
effectively monitored, the system must be in closed loop
operation.

Downloaded from www.Manualslib.com manuals search engine
On-Board Diagnostics
Catalyst monitoring. Thisstrategy monitors the outputofthe
precatalyst and post-catalyst oxygen sensors, comparing the
oxygen content going into the catalytic converter to the
oxygen leaving the converter.
The diagnostic executive
lknows that most of the oxygen
should be used up during the oxidation phase. If it detects
higherthan programmed values, afault is set and the MIL
illuminates.
Misfire detection. This strategy monitors crankshaft speed
fluctuations and determines if an enoine misfire occurs bv
monitoring variations in speed between each crankshaft
sensortrigger point. This strategy is so finely tuned that it can
determine the severity of the misfire.
The system determines
if a misfire is occurring, as well as
other pertinent misfire
information such as:
Specific
cylinder(s)
Severity of the misfire event
Emissions relevant or catalyst damaging
Misfire detection is an on-going monitoring process that is
only disabled under certain limited conditions.
Secondary air injection monitoring. Secondary air
injection is used to reduce HC and CO emissions during
engine warm up. Immediately following a cold engine start
(-1 0" to 40°C), fresh air (and therefore oxygen) is pumped
directly into the exhaust
manifold. By injecting additional
oxygen into the exhaust manifold, catalyst warm-up time is
reduced.
Secondary air system components are:
Electric air injection pump
* Electric pump relay
* Non-return valve
Vacuum
I vent valve
- Stainless steel air injection pipes
Vacuum reservoir
The secondary air system is monitored via the use
of the pre-
catalyst oxygen sensors. Once the air pump is active and air
is injected into the system, the signal at the oxygen sensor
reflects a lean condition. If the oxygen sensor signal does not
change, a fault is set and the faulty
bank(s) identified. If after
completing the next cold startafault is again present, the MIL
illuminates.

Downloaded from www.Manualslib.com manuals search engine
On-Board Diagnostics
Readiness codes indicate whether the OED Ii system is
actually ready to monitor the various emission control
systems on the vehicle. The vehicle must complete a drive
cycle to set readiness codes. The code is binary:
0 for ready
1 for not ready
f
4 The parameters which are monitored for readiness are:
llM readiness codes
1. Catalyst efficiency
2. Catalyst heating
3. Fuel tank evaporative control
4. Secondary air injection
5.
NC refrigerant
6. Oxygen sensors
7. Oxygen sensor heaters
8. Exhaust gas recirculation
Readiness codes are set to 1 (not ready) in the following
cases:
~9~~.f~[<+t~t~p:,~;:#j~~{]~y~ ,,... , , 8701Dbd001
The battery or ECM is disconnected.
When
all zeros are displayed, the system has established
DTCs are erased after completion of repairs and a drive
cycle is not completed.
readiness. Readiness codes
can be displayed using BMW
and aftermarket scan tools.
An
OED II scan tool can be used to determine IIM readiness.
Diagnostic trouble codes (DTCs)
SAE standard J2012 mandates a 5-digit diagnostic trouble
code (DTC) standard. Each digit represents a specific value.
Emission related DTCs
start with the letter P for power train.
When the engine service
light (MIL) is illuminated it indicates
that a DTC has been stored.
DTCs are stored as soon as they occur, whether or not the
engine service light illuminates.
DTCs store and display a time stamp.
DTCs record the current fault status: Present, not currently
present, or intermittent.

Downloaded from www.Manualslib.com manuals search engine
On-Board Diagnostics
l~utomatic transmission diagnostic trouble codes (continued)
P-code
1 Pi844
I I
14 /Pressure Control Solenoid 'D' Circuit Low
I I PI841 11 /Pressure Control Solenoid 'A' Circuit Low
BMW-FC
Pi842
I
P2722 15 I Pressure Control Solenoid 'E' I
DTC
Definition
Pi 845
Pi 882
Pi 883
PI 889
PI891
PI 892
PI 893
Pi 843 3 8
2 Pressure Control Solenoid '0' Circuit Low
5
57
58
96
96
96
83
P2729
P2730
P2759
P2761
P2763
P2764
Pressure Control Solenoid 'E' Circuit Low
2-3 Shift Circuit High
3-4 Shift Circuit High
System Voltage
- Electrical
System Voltage High Input
System Voltage Low Input
SUDP~V Voltaqe Pressure Control SoienoidIShift Solenoid Circuit High
~~ ~~ ~ Engine diagnostic trouble codes: M52 engine
5
5
4
4
4
4
I I
Pressure Control Solenoid 'E' Control Circuit Low
Pressure Control Solenoid
'E' Control Circuit High
Torque Converter Clutch Pressure Control
Solenoid Control Circuit Electrical
Torque Converter Clutch Pressure Control Solenoid Control
Circuitlopen
Torque Converter Clutch Pressure Control Solenoid Control Circuit High
Torque Converter Clutch Pressure Control Solenoid Control Circuit Low
DTC Definition
Mass or Volume Air
Flow Circuit RangeIPerformance
lntalte Air Temperature Sensor 1 Circuit Rangelperformance
Engine Coolant Temperature Circuit RangeIPerformance
ThrottieIPedai Position SensorISwitch 'A' Circuit
ThrottleIPedai Position SensorISwitch 'A' Circuit
P-code
PO1
01
PO1 11
PO116
PO120
PO120
PO1 20 BMW-FC
8 14
10
112
113
POI 20 1173 /~hrottie/~edal Position SensorISwitch 'A' Circuit
118
ThrottieIPedai Position SensorISwitch 'A' Circuit

Downloaded from www.Manualslib.com manuals search engine
OBD-15
On-Board ~iagnosticsl
Engine diagnostic trouble codes: M52 engine (continued)
P-code
PO340
PO412
PO420
PO430
PO440
PO441
PO442
PO443
PO500
PO505
PO600
PO601
PO601
I PO601
~1132
~1133
BMW-FC
65
62
233
234
250 144
-
145
68
214
i I
DTC Definition
Camshalt Position Sensor 'A' Circuit (Bank 1 or Single Sensor)
Secondary Air Injection System Switching Valve A Circuit
Catalyst System Efficiency Below Threshold
(Bank 1)
Catalyst System Efficiency Below Threshold (Bank 2)
Evaporative Emission System
Eva~orative Emission Svstem Incorrect Purge Flow .
Evaporative Emission System Leak Detected (small leak)
Evaporative Emission System Purge Control Valve Circuit
Vehicle Speed Sensor 'A'
204
21 7
100
170
171
188
189
PI161
PI180
PI181
PI184
PI185
PI178
02 Sensor Heater Control Circuit (Bank 2 Sensor 2) I
idle Air Control System
Serial Communication
Link
Internal Control Module Memory Check Sum Error
Internal Control Module Memory
Check Sum Error
Internal Control Module Memory
Check Sum Error
02 Sensor Heater Control Circuit (Bank 1 Sensor
1)
02 Sensor Heater Control Circuit (Bank 2 Sensor 1)
Mass or Volume Air Flow Circuit RangeIPerlormance Problem PI140
I
I I
P1188 1227 I Fuel Control (Bank 1 Sensor 1)
PI145 150 /Solenoid Valve Running Losses Control Circuit Electrical
149
122
223
224
220 221
231
I I
P1189 1228 I Fuel Control (Banlc 2 Sensor 1)
Fuel Trim Adaptation Additive High (Bank 2) (M52: Engine Oil Temperature Sensor Circuit)
02 Sensor Signal Circuit Slow Switching from Rich to Lean
(Bank 1 Sensor 2)
02 Sensor Signal Circuit Slow Switching from Rich to Lean
(Bank 2 Sensor 2)
H02S Sensor Voltage Excursion Electrical (Banlc 1 Sensor 1)
HO2S Sensor Voltage Excursion Electrical (Banlc 2 Sensor 1)
02 Sensor Sianai Circuit Slow Switchina from Rich to Lean (Bank 1 Sensor 1)
02 Sensor Signal Circuit Slow Switching from Rich to Lean (Bank 2 Sensor 1) PI179
I I
PI190 1235 I Pre Catalyst Fuel Trim System (Banlc 1)
PI186 1190 102 Sensor Heater Control Circuit (Banlc 1 Sensor 2)
232
I I
PI191 1236 I Pre
Catalyst Fuel Trim System (Banlc 2)
PI192
. . -- - i Pi193 1226 I Post Catalvst Fuel Trim Svstem (Bank 2)
225
PI397
I I
Post Catalyst Fuel Trim System (Bank 1)
PI421 1246 /Secondarv Air System (Bank 2)
18
Secondary Air System (Bank
1) PI423
Camshaft Position Sensor '0' Circuit (Bank 1)
I 245

Downloaded from www.Manualslib.com manuals search engine
On-Board ~iaanosticsl
Engine diagnostic trouble codes: M54 engine
P-code
BMW-FC Explanation
PO01 I / 103 I 'A' Camshaft Position Timing Over-Advanced or System Performance (Banlc 1) I I
PO012 1105 I 'A' Camshaft Position Timing Over-Retarded (Bank 1) I I
PO01 4 1104 I 'B' Camshaft Position Timing Over-Advanced or System Performance (Bank 1)
PO01 5
PO030
PO031
PO032
I 1
PO038 179 / HO2S Heater Control Circuit High (Bank 1 Sensor 2)
I I -.
I I
PO050 1 55 I H02S Heater Control Circuit (Bank 2 Sensor 1)
106
25
25
25
PO036
I I
PO051 1 55 I H02S Heater Control Circuit Low (Bank 2 Sensor 1)
'B' Camshaft Position Timing Over-Retarded (Bank 1)
H02S Heater Control Circuit (Bank 1 Sensor 1)
H02S Heater Control Circuit Low (Bank 1 Sensor 1)
H02S Heater Control Circuit Hiqh (Bank 1 Sensor 1)
PO037 1 79 I HO2S Heater Control Circuit Low (Bank 1 Sensor 2)
79
HOPS Heater
Control Circuit (Banlc 1 Sensor 2)
PO052
PO056
PO057
PO058
I I
PO1 03 / 8 I Mass or Volume Air Flow Circuit High. Input
I I -.
I I
PO1 07 1 197 I Manifold Absolute PressureIBarometric Pressure Circuit Low Input
55
61
61
61
PO101
I I
POI08 1197 / Manifold Absolute PressureIBarometric Pressure Circuit High Input
H02S Heater Control Circuit High (Bank 2 Sensor 1)
H02S Heater Control Circuit (Bank 2 Sensor 2)
HO2S Heater Control Circuit Low (Bank 2 Sensor 2)
HO2S Heater Control Circuit Hiqh (Banlc 2 Sensor 2)
PO102 18 I Mass or Volume Air Flow Circuit Low Input
149
I I -
PO122 112 ThrottleIPedai Position SensorISwitch 'A' Circuit Low
PO123 1112 I ThrottleIPedal Position SensorISwitch 'A' Circuit High
Mass
or Volume Air Flow Circuit
RangeIPerformance
PO112
PO113
PO1 17
PO118
PO121
14
14
10
10
118
PO128
PO1 31
PO132
PO133
PO133
PO1 34 Intake
Air Temperature Sensor 1 Circuit Low
Intake Air Temperature Sensor 1 Circuit High
Engine Coolant Temperature Circuit Low
Engine Coolant Temperature Circuit High
ThrottleIPedal Position SensorISwitch 'A' Circuit RanqeIPerformance
I I
168
150
150
229
231
150
PO135
Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
02 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
02 Sensor Circuit High Voltage (Bank 1 Sensor 1)
02 Sensor Circuit Slow Response (Bank
1 Sensor 1)
02 Sensor Circuit Slow Response
(Banlc 1 Sensor 1)
02 Sensor Circuit No Activitv Detected
(Banlc 1 Sensor 1)
188 02 Sensor Heater Circuit (Bank 1 Sensor 1)

Downloaded from www.Manualslib.com manuals search engine
On-Board ~ia~nosticsl
Engine diagnostic trouble codes: M54 engine (continued) I -.
P-code BMW-FC Explanation
PO223 113 ThrottlelPedal Position SensorlSwitch '0' Circuit High
PO261 / Cylinder 1 Injector Circuit Low
PO271 Cylinder 4 Injector Circuit High
PO273 Cylinder 5 Injector Circuit Low
Cylinder 2 Injector Circuit High
Cylinder 3 Injector Circuit
Low
Cylinder 3 Injector Circuit High
Cylinder 4
iniector Circuit Low
PO265
PO267
PO268
PO270
, I
PO277 1 23 1 Cylinder 6 Injector Circuit High
5
22
22
24
I I
PO274
PO301
PO302
PO303
PO304
PO276 1 23 I Cylinder 6 Injector Circuit Low
33
I
I -
I I
PO31 3 1 240 I Misfire Detected with Low Fuel Cylinder 5 Injector Circuit High
238
239
240
241
PO305
I I
Cylinder 1 Misfire Detected
Cylinder 2 Misfire Detected
Cylinder 3 Misfire Detected
Cylinder 4 Misfire Detected
PO313
PO306 1 243 I Cylinder 6 Misfire Detected
242
PO313
PO313
PO31 3
PO327
Cylinder 5 Misfire
Detected
PO31 3 1239 I Misfire Detected with Low Fuel
238
PO332
PO335
PO339 - PO340
Misfire Detected with Low Fuel
241
242
243
57
PO344
PO365
PO369
PO41 3
PO414
PO420
Misfire Detected with Low Fuel
Misfire Detected with Low Fuel
Misfire Detected with Low Fuel
Knock Sensor 1 Circuit Low
(Banlc 1 or Sinale Sensor)
59
83
83
65
-
Knoclc Sensor 2 Circuit Low (Banlc 2)
Crankshaft Position Sensor
'A' Circuit
Crankshaft Position Sensor
'A' Circuit Intermittent
Camshaft Position Sensor 'A' Circuit (Bank 1 or Single Sensor)
65
18
18
62
62
233 Camshaft Position Sensor
'A' Circuit Intermittent (Bank 1
or Single Sensor)
Camshaft Position Sensor
'B' Circuit (Banlc 1)
Camshaft Position Sensor 'B' Circuit Intermittent (Bank 1)
Secondary Air Injection System Switching Valve A Circuit Open
Secondary Air
Injection System Switching Valve A Circuit Shorted
Catalyst System Efficiency Below Threshold (Bank 1)

Downloaded from www.Manualslib.com manuals search engine
I On-Board Diagnostics
Engine diagnostic trouble codes: M54 engine (continued)
P-code
BMW-FC Explanation
Catalyst System Efficiency Below Threshold (Bank 2)
PO430
PO443
PO444
PO445
PO455
PO456
PO491
PO492
PO500
PO441 1250 / Evaporative Emission System Incorrect Purge Flow
234
I I
68
68
68 143
143
245
246
214
PO604
PI083
PI084
PI085
PI086
Evaporative Emission System Purge Control Valve Circuit
Evaporative Emission System Purge Control Valve Circuit Open
Evaporative Emission System Purge Control Valve Circuit Shorted
Evaporative Emission System Leak Detected (large leak)
Evaporative Emission System Leak Detected (very
small leak)
Secondary Air injection System Insufficient Flow (Bani( 1)
Secondary Air Injection System insufficient Flow
(Banic 2)
Vehicle Speed Sensor
'A'
Idle Air Control System PO505
.
PI 087
PI 088
PI089
PI090
PO600 / 217 I Serial Communication Link
204
100
202
202
203
203
PI091
PI092
PI093
PI094
Pllll
PI112
PI120
Internal Control Module Random Access Memory (RAM) Error
Fuel Control Limit Mixture Too Lean (Bank 1 Sensor
1)
Fuel Control Limit Mixture Too Rich (Bank 1 Sensor 1)
Fuel Control Limit Mixture Too Lean (Bank 2 Sensor 1)
Fuel Control Limit Mixture Too Rich (Banic 2 Sensor 1) ~ ~
229
229
230 235
PI121
PI122
PI123
02 Sensor Circuit Slow Response in Lean Control Range (Bank 1 Sensor 1)
02 Sensor Circuit Slow Response in Rich Control Range (Bank 1 Sensor
1)
02 Sensor Circuit Slow Response in Lean Control Range (Banlc 1 Sensor 2)
Pre Catalyst Fuel Trim System Too Lean
(Bank 1)
236
235
236
230
11
11
114
PI134
PI135
PI136
PI137
PI138
Pre Catalyst Fuel Trim System Too Lean (Banic 2)
Pre Catalyst Fuel Trim System Too Rich
(Bank 1)
Pre Catalyst Fuel Trim System Too Rich (Bank 2)
02 Sensor Circuit Slow Response in Rich Control Range (Banic 2 Sensor 1)
Engine Coolant Temperature Sensor Radiator Outlet Low Input
Engine Coolant Temperature Sensor Radiator Outlet High Input
Pedal Position Sensor Circuit
117
110
110
25
25
25
79
79 Pedal Position Sensor 1
RangeIPerformance Problem
Pedal Position Sensor 1 Low Input
Pedal Position Sensor 1 High Input
02 Sensor Heater Circuit Signal Intermittent (Bank 1 Sensor 1)
02 Sensor Heater Circuit Low Voltage (Bank 1 Sensor
1)
02 Sensor Heater Circuit High Voltage (Bank 1 Sensor 1)
02 Sensor Heater Circuit Signal Intermittent (Bank 1 Sensor 2)
02 Sensor Heater Circuit Low Voltage
(Banic 1 Sensor 2)
-
-