Dtc14 - Cmp Sensor System Fault; Major Faulty Event; Conditions For Setting The Dtc; Action Taken When The Dtc Sets - Isuzu 4HL1 Workshop Manual

DTC14 - CMP Sensor System Fault

Circuit Description
The CMP (cam position) sensor is installed to each
cylinder head and, when the hole on the camshaft gear
passes the sensor, a CMP signal is generated. Five
CMP pulses are generated per cycle (one rotation of
camshaft). The ECM identifies the cylinder from the
CMP signal as well as the CKP signal sent from the
CKP sensor and determines the crank angle, and uses
this angle in fuel injection control and engine speed
calculation. These tasks are usually performed based
on the CKP signal but if the CKP sensor fails, the CMP
signal will substitute for the CKP signal.
DTC14 will be set when the number of CMP signals
received by the ECM is not correct.

Major Faulty Event

• Poor startability

Conditions for Setting the DTC

No CMP signal is input while the CKP signal is input to
the ECM 450 times.

Action Taken When the DTC Sets

• After the DTC is set and the engine runs at idle,
the ECM will illuminate the CHECK ENGINE lamp
(MIL).
• When the CKP sensor is sound, the ECM will
control the powertrain using the CKP signal.
25 6 8 27 26
CKP CMP
Sensor Sensor
63 66 6764
69 68
ITP EGR Valve
Sensor Position
Sensor
Conditions for Clearing MIL/DTC
When the system fails and the DTC is stored to the
ECM, even repairing the faulty portion will not clear the
DTC from the memory. To clear the DTC, conduct the
following steps.
1. Turn off the idle position switch for not less than 1
second but not more than 3 seconds. (Press the
accelerator pedal.)
2. Turn on the idle position switch for not less than 1
second but not more than 3 seconds. (Release the
accelerator pedal.)
3. Turn off the idle position switch for not less than 1
second but not more than 3 seconds. (Press the
accelerator pedal.)
4. Turn on the idle position switch for not less than 1
second but not more than 3 seconds. (Release the
accelerator pedal.)
5. Turn off the idle position switch for not less than 1
second but not more than 3 seconds. (Press the
accelerator pedal.)
6. After the above operations are properly completed,
the CHECK ENGINE lamp (MIL) illuminates for 3
seconds to report the memory is cleared.
7. Turn off the starter switch. Wait for 5 seconds and
turn on the starter switch again.
When Tech 2 has been connected to the vehicle, the
DTC can be cleared through the memory clear
operation with Tech 2.
Engine Control System 1A-93
ECM
(Engine
Control
Module)
Common
Rail
Pressure
Sensor
LNW21AMF006901-X