Camshaft Position Sensor 2 - Below Limit
P1397
Camshaft Position Sensor 2 - Below Limit
Function
The signal from camshaft position sensor 2 is required for identifying the position of the camshaft for bank 2. CMP sensor 2 is installed only in USA vehicles.
Diagnosis conditions
- Engine running
P1397:
Wiring Diagram
Diagnosis Procedure
Signal implausible
Below limit
Above limit
1 Check power supply to CMP sensor.
1. Remove connector of CMP sensor 2.
2. Switch on the ignition.
3. Connect voltmeter to pin 1 (negative) and pin 3 (positive).
Display: approx. 5 V
2 Check power supply wiring for continuity.
1. Remove connector of CMP sensor 2.
2. Connect special tool 9637 to wiring harness (DME control module connector).
3. Connect ohmmeter to special tool 9637, pin III/7, and to CMP sensor connector 2, pin 3.
Display: 0 - 5 ohms
4. Connect ohmmeter to special tool 9637, pin III/17, and to CMP sensor connector 2, pin 1.
Display: 0 - 5 ohms
3 Perform adaptation.
1. Switch on the ignition.
2. Wait one minute.
Do not press the accelerator.
3. Switch off the ignition for at least 10 seconds.
4. Read out the fault memory.
4 Check CMP sensor signal.
1. Connect special tool 9637.
2. Connect engine tester. Using special input, connect positive cable to pin III/19, negative cable to pin III/17.
3. Start the engine.
The display pictured opposite should appear on the oscilloscope:
5 Check signal wire from DME control module, pin III/19, to CMP sensor.
1. Connect special tool 9637 to wiring harness (DME control module connector).
2. Remove connector of CMP sensor.
3. Connect ohmmeter to special tool 9637, pin III/19, and to CMP sensor connector 2, pin 2.
Display: 0 - 5 ohms
6 Check signal wire from DME control module, pin III/19, to CMP sensor for short to ground.
1. Connect special tool 9637 to wiring harness (DME control module connector).
2. Remove connector of CMP sensor.
3. Connect ohmmeter to special tool 9637, pin III/19, and ground.
Display: infinity ohms
If 0 - 5 ohms is displayed, check wiring harness for chafing and pinching damage.
7 Check signal wire from DME control module, pin III/19, to CMP sensor for short circuit to B+.
1. Connect special tool 9637 to wiring harness (DME control module connector).
2. Remove connector of CMP sensor.
3. Connect voltmeter to special tool 9637, pin III/19, and ground.
Switch on the ignition.
Display: 0 V
If battery voltage is displayed, check wiring harness for chafing and pinching damage.
DME Connector Assignment
NOTE: The DME control module has 134 terminals which are divided between five connectors.
Connector I (9-pole)
Connector II (24-pole)
Connector III (52-pole)
Part 1:
1 - Knocking signal
2 - Fuel injector, cyl. 5
3 - EVAP canister purge valve
4 - Variable-length manifold
5 - Oil temperature sensor
6 - not assigned
7 - 5-volt supply for camshaft position sensor and differential pressure sensor
8 - Signal, throttle position sensor 2
9 - Ground, mass air flow sensor
10 - 5-volt supply for throttle actuation
11 - Triggering of secondary air pump relay (terminal 85)
12 - not assigned
13 - Start enable, Tiptronic (P + N)
14 - Pilot light, engine compartment fan
15 - Fuel injector, cyl. 3
16 - not assigned
17 - Ground, sensors
18 - not assigned
19 - Signal, camshaft position sensor 2
20 - Signal, camshaft position sensor 1
21 - not assigned
22 - Engine coolant temperature sensor
23 - Signal, mass air flow sensor
24 - Signal, throttle position sensor 1
25 - Ground, throttle position sensors 1 + 2
26 - not assigned
27 - Fuel injector, cyl. 4
28 - Fuel injector, cyl. 6
29 - not assigned
30 - Secondary air valve
31 - not assigned
32 - Signal A, speed sensor
33 - not assigned
34 - Intake air temperature sensor
35 - not assigned
36 - Input, knock sensor 2
37 - Ground, knock sensor 2
38 - not assigned
39 - not assigned
40 - Fuel injector, cyl. 2
41 - Fuel injector, cyl. 1
42 - Throttle motor actuator
43 - Throttle motor actuator
44 - not assigned
45 - Shield, speed sensor
46 - Signal B, speed sensor
47 - not assigned
48 - not assigned
49 - Input, knock sensor 1
50 - Ground, knock sensor 1
51 - not assigned
52 - not assigned
Connector IV (40-pole)
Part 1:
1 - Interlock clutch switch
2 - not assigned
3 - not assigned
4 - Coolant fan, stage 1
5 - Variant coding (ground for Tiptronic)
6 - A/C compressor requirement
7 - Ground, pedal sensor 1
8 - Signal, pedal sensor 1
9 - 5-volt supply for pedal sensor 1
10 - Triggering of fuel pump relay (terminal 85)
11 - Dim information from instrument cluster
12 - Ground, pedal sensor 2
13 - Signal, pedal sensor 2
14 - 5-volt supply for pedal sensor 2
15 - Ground, differential pressure sensor
16 - Crash signal (airbag)
17 - Speed signal output
18 - Cruise control pilot light
19 - Cruise control switch "Off"
20 - Coolant fan, stage 2
21 - Signal, differential pressure sensor
22 - Speed signal from ABS control module
23 - Cruise control clutch switch
24 - Stop light switch 1
25 - Cruise control switch "Set"
26 - not assigned
27 - Cruise control switch "Resume"
28 - Stop light switch 2
29 - not assigned
30 - EVAP canister shutoff valve
31 - Check Engine MIL
32 - not assigned
33 - Fuel gauge
34 - Fuel reserve pilot light
35 - not assigned
36 - CAN high (PSM)
37 - CAN low (PSM)
38 - not assigned
39 - Medium pressure switch (A/C)
40 - Start-inhibit relay (terminal 85)
Connector V (9-pole)
