ECM SYSTEM
WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, DM
1-127
DTC 341-Camshaft Input Signal Noise
• Hardware: Camshaft Position sensor
• Enabling Conditions: Key On, Engine Running
• Set Conditions: Electrical noise or irregular cam pattern detected causing more than 1 cam re-synchronization
events in less than 700 ms.
• Corrective Action(s): Illuminate MIL and disable fuel adaptive learn for remainder of key-cycle.
• Emissions related fault
• Possible Causes: CMP+ or CMP circuits in wrong connector terminal slot, improper CMP signal due to sensor
air gap too large, excessive metal on sensor tip, improper wiring, intermittent connection in sensor circuitry,
intermittent sensor internal problem
The camshaft position sensor is a magnetic pick-up sensor installed in the engine block or valve train adjacent to
a "coded" trigger wheel located on or off of the camshaft. The sensor-trigger wheel combination is used to determine
cam position so the ECM can determine which piston is coming up on TDC. Determination of the camshaft position
is necessary to identify the stroke (or cycle) of the engine to properly activate the fuel injection system and ignition
(for coil-on-plug engines) for precise engine control.
For a cam synchronized engine, the ECM must see a valid camshaft position signal while running. If no signal is
present, the signal amplitude is too high (due to improper air gap with respect to trigger wheel), or an irregular cam
pattern is detected causing the ECM to resynchronize this fault will set. Irregular cam patterns can be detected by the
ECM and can be caused by: electrical noise, poor machining of trigger wheel, or trigger wheel run out and/or gear
lash. In some instances this fault can cause rough engine operation and can cause the engine to stall or die if attached
with coil-on-plug ignition engines.
Ensure cam circuit used with VR/magnetic pick-up sensors are properly twisted.
DTC 342-Loss of Camshaft Input Signal
• Hardware: Camshaft Position sensor
• Enabling Conditions: Key On, Engine Running above 1000 min
-1
(rpm)
• Set Conditions: Loss of camshaft position signal while valid crankshaft position signals continue for 2.5 engine
cycles for longer than 1 second
• Corrective Action(s): Illuminate MIL
• Emissions related fault
• Possible Causes: Loss of feed voltage to CMP sensor, loss of signal or ground circuits, faulty sensor, faulty ECM
or damaged engine components
The camshaft position sensor is a magnetic sensor (hall-effect) installed in the engine block or valve train adjacent
to a "coded" trigger wheel located on or off of the camshaft. The sensor-trigger wheel combination is used to
determine cam position (with respect to TDC cylinder #1 compression). Determination of the camshaft position is
necessary to identify the stroke (or cycle) of the engine to properly activate the fuel injection system and ignition (for
coil-on-plug engines) for precise engine control.
For a cam synchronized engine, the ECM must see a valid camshaft position signal while running. In some
instances this fault can cause rough engine operation and can cause the engine to stall or die if attached with
coil-on-plug ignition engines.
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