5032732 JOHNSON COIL, IGNITION

Illustration 1 g01075596
Schematic of the circuit for the PWM sensors
Test Step 1. Inspect the Electrical Connectors and Wiring
Illustration 2 g01075546
(1) ECM connectors J2/P2
(2) ECM connectors J1/P1
(3) 16 amp circuit breaker
(4) J12/P12 connectors for the harness from the PWM sensors
Set the engine control to the OFF/RESET mode. Switch 16 amp circuit breaker (3) to the OFF position. Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Thoroughly inspect the following connectors:
J1/P1 connectors
J2/P2 connectors
J12/P12 connectors on the terminal box
Check the torque of the allen head screw for the ECM connector. The proper torque is 6 1 N m (55 9 lb in).
Illustration 3 g01075551
Harness sides of the P1 connector
(P1-2) 5 volt supply
(P1-3) Return
(P1-4) 8 volt supply
(P1-5) Return
(P1-10) Signal for the inlet manifold air pressure
(P1-11) Signal for the humidity
(P1-12) Signal for the atmospheric pressure
Illustration 4 g01075555
Harness sides of the P2 connector
(P2-68) Signal for the engine coolant pressure (outlet)
Illustration 5 g00896248
Harness side of the P12 connector
(P12-A) 5 volt supply
(P12-C) Return
(P12-D) Signal for the atmospheric pressure
(P12-G) Signal for the humidity
(P12-L) 8 volt supply
(P12-M) Signal for the inlet manifold air pressure
(P12-N) Return
(P12-P) Signal for the engine coolant pressure (outlet)
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the PWM sensors.
Illustration 6 g01075559
Left side view
(1) Sensor for the engine coolant pressure (outlet)
(2) Sensor for the inlet manifold air pressure
Illustration 7 g01075564
Left side views
(3) Sensor for humidity
(4) Sensor for atmospheric pressure
Check the harness and wiring for abrasion and for pinch points from each PWM sensor to the ECM. Expected Result:All of the connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check for Active "8 Volt DC Supply" Diagnostic Codes and "5 Volt Sensor DC Supply" Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector on the terminal box. Refer to Troubleshooting, "Electronic Service Tools".
Switch the 16 amp circuit breaker ON. Set the engine control to the STOP mode.
Observe the "Active Diagnostic" screen on Cat ET. Allow a minimum of thirty seconds for any codes to activate. Look for these codes:
41-03 8 Volt DC Supply short to +batt
41-04 8 Volt DC Supply short to ground
262-03 5 Volt Sensor DC Supply short to +batt
262-04 5 volt Sensor DC Supply short to groundExpected Result:There are no active "8 Volt DC Supply" diagnostic codes or "5 Volt Sensor DC Supply" diagnostic codes.Results:
No codes - There are no active diagnostic codes for the power supplies. Proceed to Test Step 3.
Active code - There is an active diagnostic code for a power supply. This procedure will not work when this type of code is active.Repair: Refer to Troubleshooting, "+8 V Sensor Voltage Supply", or Troubleshooting, "+5 V Sensor Voltage Supply".STOPTest Step 3. Check for Active Diagnostic Codes for the PWM Sensors
Turn on the "Active Diagnostic" screen on Cat ET. Determine if any of these diagnostic codes are active:
106-03 Air Inlet Pressure Sensor open/short to +batt
106-08 Air Inlet Pressure Sensor noisy signal
109-03 Engine Coolant Outlet Pressure open/short to +batt
109-08 Engine Coolant Outlet Pressure noisy signal
1758-03 Specific Humidity Sensor open/short to +batt
1758-08 Specific Humidity Sensor noisy signal
1759-03 Exhaust Back Pressure Sensor open/short to +batt
1759-08 Exhaust Back Pressure Sensor noisy signalExpected Result:None of the above codes are active.Results:
OK - None of the above codes are active.Repair: If any of