Analog Input Related Failures; Rack Position Sensor; P1202/4: Failure With Rack Position Sensor (Low Voltage) - Yanmar 3TNV82A Troubleshooting Manual

FAILURE DIAGNOSIS

Analog Input Related Failures

Rack position sensor

(1) P1202/4: Failure with Rack Position Sensor (Low Voltage)

DTC P1202/4
DTC Detecting Conditions
1 - Precondition; 2 - Detecting condition(s);
3 - Flashing pattern of failure indicator
1. Key switch ON.
2. The sensor voltage lower limit and below [at E-ECU activation,
engine running]
3. Seven flashes.
Movement at Error occurrence
Error Mode [Run Under Restrictions]:
The engine continues to run in on-error engine control mode.
If any error is detected at E-ECU activation, it takes 1 - 10 seconds from the starter
begins to rotate until the engine starts.
Run restricted? Yes: • The High idle speed is restricted to one of the following, whichever smaller:
Recovery No.
Conditions
Remarks The High and Low idle speeds must be equal to those specified in the engine
specifications.
Estimation of Failure cause/Error condition
• The connector may not be properly connected.
• Wiring defect of the harness
The rack position sensor's signal wires may be disconnected or short-circuited with GND.
•
The SENSOR 12V wire may be disconnected or short-circuited with GND (*NOTE).
•
The SENSOR GND wire may be short-circuited with POWER SUPPLY (*NOTE).
•
*NOTE) If the SENSOR 12V wire is short-circuited with GND or SENSOR GND wire is short-circuited with
POWER SUPPLY, the E-ECU's power supply line fuse 10A might be blown.With this fuse blown, the
E-ECU may fail to detect/indicate the error, and to store the error history.
The rack position sensor may be faulty.
Output defect of the rack position signal by a disconnection or a short circuit of the inner wiring
•
• The E-ECU internal circuitry may be faulty.
1-8
DTCs (Diagnostic Trouble Codes) General Description
80% of the pre-error High idle speed
•
150% of the Low idle speed
•
• The fuel injection rate is restricted.
Rack Position Sensor Error (Low Voltage)
Connector
Harness
Rack position sensor
E-ECU
TNV DI Service Manual
Check points