5031779 JOHNSON *COVER, UNDER

Table 1
Diagnostic Trouble Codes    
CDL Code     Code Description     Comments    
41-3     8 VDC Supply : Voltage Above Normal     The code is logged.    
41-4     8 VDC Supply : Voltage Below Normal     The code is logged.    
262-3     5 Volt Sensor DC Power Supply : Voltage Above Normal     The code is logged.
All sensors are set to default values.    
262-4     5 Volt Sensor DC Power Supply : Voltage Below Normal     The code is logged.
All sensors are set to default values.    
274-21     Atmospheric Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
289-21     Fuel Pressure Sensor - Before Fuel Filter : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
460-21     Fuel Pressure Sensor - After Fuel Filter : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
1785-21     Intake Manifold Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
2131-3     5 v Sensor DC Power Supply #2 : Voltage Above Normal     The code is logged.
Engine power may be derated.    
2131-4     5 v Sensor DC Power Supply #2 : Voltage Below Normal     The code is logged.
Engine power may be derated.    
3385-21     EGR Intake Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
3464-21     DPF #1 Intake Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
3493-21     Aftertreatment #1 Secondary Air Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    System OperationThe Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the following sensors:
Engine oil pressure sensor
Barometric pressure sensor
Crankcase pressure sensor
Intake manifold pressure sensor
NRS absolute pressure sensor
Fuel rail pressure sensor
Tertiary inlet fuel pressure sensor
Tertiary outlet fuel pressure sensor
ARD fuel pressure #1 sensor (Pilot)
ARD fuel pressure #2 sensor (Main)
NRS delta pressure sensor
Aftertreatment #1 gas temp #1
DPF inlet pressure #1 sensor
Aftertreatment #1 secondary air pressure sensor
Aftertreatment #1 ID moduleThe Electronic Control Module (ECM) supplies a regulated voltage of 8.0 0.2 VDC to the following sensor:
Throttle sensorThe supply voltage for the sensors is routed from the ECM to terminal 1 of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal 2 of each sensor connector. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If any of the diagnostic codes are active, a sensor may have been damaged. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if a sensor has been damaged.
Illustration 1 g02368176
Illustration 2 g02359049
Terminal locations at the P2 ECM connector for the passive analog sensors (P2-30) Return (P2-54) Return (P2-72) +5 Sensor Power Supply (Left side of the engine) (P2-80) +5 Sensor Power Supply (P2-81) +5 Sensor Power Supply (Right side of the engine) (P2-82) CEM +5 Sensor Power Supply (P2-83) Engine Return (right side) (P2-92) Aftertreatment#1 ID Module Return (P2-93) Engine Return (left side)
Illustration 3 g02173860
Terminal locations at the P1 ECM connector for the passive analog sensors (P1-4) +8 Sensor Power Supply
Illustration 4 g01240891
Sensor connector (A) 5 V or 8 V sensor supply (B) Sensor return (C) Signal
Table 2
Troubleshooting Test Steps     Values     Results    
1. Check for Codes
A. Connect Cat® ET to the service tool connector.
B. Determine if a diagnostic code is present.
   
Code
   
Results: A -3 or -4 code is present.
Repair: Inspect the wiring at each sensor. Look for broken wiring or problems with a connector. Make the necessary repairs.
STOP
Results: A -21 code is present. - There is an intermittent loss or solid loss of 5 v supply to the sensor. Proceed to Test Step 2.
   
2. Check the Sensor Supply
A. Turn the keyswitch to the ON position. Do not start the engine.
B. Perform the "Wiggle Test" in Cat ET.
C. Unplug the suspect sensor.
D. Place a jumper wire across pin 1 to pin 2.
   
41-4, a 2131-4 or a 262-4
   
Results: A 41-4, a 2131-4 or a 262-4 code is activated.
Repair: Remove the sensor. Check the sensor passage for a blockage or obstruction. Also, check for moi