The Electronic Ignition (EI)
module supplies a ground to the cylinder #4 signal wire whenever it determines cylinder #4 has just fired on its compression stroke. The EI module uses capacitive pickup plates located under the 1/4
coil pack to determine the polarity sequence and voltage amplitude of the cylinder 1/4
secondary ignition. The PCM
supplies 5 volts
on the signal line and expects to see the cylinder #4 signal wire go low after every 14 crankshaft pulses (2 revolutions).
This is used to determine the position of the camshaft, except under decel. The PCM only uses the transition from 5 to 0 volts
as a valid TDC compression #4 cylinder signal. DTC P0341 sets when the PCM detects extra cam pulses (more than one cam pulse within two crankshaft revolutions). DTC PARAMETERS
DTC P0341 will set if the PCM
detects 11 or more consecutive extra cam pulses (cylinder #4 signal line is pulled to ground too often) when MAP
is greater than 30 kPa.
If the PCM
detects 20 correct consecutive cam pulses, DTC P0341 will pass for the rest of the ignition cycle.
DTC P0341 diagnostic runs continuously until 20 correct cam pulses have been received when the vehicle is not in a decel.
DTC P0341 is a type B DTC. DIAGNOSTIC AIDS
Use Scan tool to monitor CMP
RESYNC COUNTER while running engine. The counter should count to 14, which indicates the number of notches passed on the crankshaft in 2 revolutions, then reset to zero when a cam pulse is received.
High resistance in the #4 secondary ignition system
or low resistance in the #1 secondary ignition system can set this DTC. Check for corroded or loose #1 or #4 secondary ignition components. Use Scan tool to monitor MISFIRE CURRENT CYL #1 and #4 which may point out an intermittent misfire causing the DTC.
A cam pulse that occurs too often without a cylinder misfire will not affect engine operation.