5032414 JOHNSON ROD, CHOKE

Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
336-2 Engine Control Switch erratic, intermittent, or incorrect The two inputs from the ECS are in the opposite state. The code is logged. The ECS can operate in four modes: OFF/RESET, START, STOP and REMOTE.The engine's Electronic Control Module (ECM) receives three signals that allow the ECM to determine the mode of operation. The input signals on P1-21 and P1-22 tell the ECM the position of the ECS. The input signals on P1-21 and P1-22 must be at the same potential or a diagnostic code will be generated. The third input signal on P1-68 tells the ECM if the ECS is in the REMOTE position. If the input signal on P1-68 is low, the ECM knows that the ECS is in the REMOTE position. The ECM knows that the engine is controlled remotely by the customer. If the input signal on P1-68 is not low, the ECM knows that the ECS is not in the REMOTE position. The ECM knows that the engine is controlled locally by the ECS on the instrument panel.When the ECS is in the REMOTE position, inputs from the customer control the operation of the engine. The following list contains some of the inputs from the customer connector and the inputs function.
c keyswitch
S remote input
C remote start 2
D remote start 1
E remote stop 1
F remote stop 2When the ECS is in the REMOTE position, the "Remote Start" relay and the "Remote Stop" relay are energized. When the remote start inputs C and D go low, the following relays energize: "Run 1" relay, "Run 2" relay, "Reset 1" relay and "Reset 2" relay. The start/run/stop inputs P1-21 and P1-22 will be pulled low. The engine will begin the start cycle. When the customer's remote stop inputs F and E are low, the following relays energize: "Stop 1" relay and "Stop 2" relay. The start/run/stop inputs P1-21 and P1-22 will be high. The engine will begin the stop function. When the ECS is in the REMOTE position, the "ECS in Remote" relay energizes. The "ECS in Remote" relay sends a signal to the customer connector that allows the customer to determine the position of the ECS.When the ECS is in the START position, the following relays energize: "Run 1" relay, "Run 2" relay, "Reset 1" relay and "Reset 2" relay. The start/run/stop inputs P1-21 and P1-22 will be pulled low. The engine will begin the start cycle.When the ECS is in the STOP position, the following relays energize: "Stop 1" relay and "Stop 2" relay. The start/run/stop inputs P1-21 and P1-22 will be high. The engine will begin the stop function.When the ECS is in the OFF/RESET position, the input for the keyswitch P1-70 is not pulled up to +Battery voltage and the ECM will not operate.
Illustration 1 g01186000
Typical example
Illustration 2 g01244072
P1 ECM connector
(P1-5) Digital return
(P1-21) "Start/Run/Stop 1"
(P1-22) "Start/Run/Stop 2"
(P1-68) "ECS Remote/Auto"
(P1-70) Keyswitch
Illustration 3 g01244073
P2 ECM connector
(P2-54) Digital return
(P2-55) Digital return
Illustration 4 g01234146
Location of ECM connectors
Test Step 1. Inspect Electrical Connectors and Wiring
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The connectors and wiring are OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check the Status of the ECS in the STOP Position
Turn the circuit breaker for the battery to the ON position.
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the ECS on the instrument panel to the STOP position.
Observe the status for the ECS on Cat ET. Expected Result:The status for the ECS is "STOP".Results:
OK - The ECS is functioning correctly. Proceed to Test Step 3.
Not OK - The status for the ECS is not "STOP". Proceed to Test Step 5.Test Step 3. Check the Status of the ECS in the START Position
Turn the ECS on the instrument panel to the START position.
Observe the status for the ECS on Cat ET. Expected Result:The status for the ECS is "RUN".Results:
OK - The ECS is functioning correctly. Proceed to Test Step 4.
Not OK - The status of the ECS is not "RUN". Proceed to Test Step 5.Test Step 4. Check the Status of the ECS in the REMOTE Position
Turn the ECS on the instrument panel to the REMOTE position.
Observe the status for the ECS on Cat ET. Expected Result:The status for the ECS is "AUTO".Results:
OK - The ECS is working correctly.Repair: The problem may be intermittent. If the problem is intermittent, perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".STOP
ECS Not OK - The status for the ECS is not "AUTO". Proceed to Test Step 6.Test Step 5. Install a Wire Jumper at the ECM in order to Simulate a START/STOP Function
Turn the ECS to the OFF/RESET position.
Disconnect the ECM connector J1/P1.
Remove wire F716-BK(Black) from P1-21. Install a wire jumper into the socket P1-21.
Remove wire F717-BK(Black) from P1-22. Install a wire jumper into the socket P1-22.
Reconnect the ECM connector J1/P1.
Fabricate a wire jumper.
Install the wire jumper between terminal 11 of the ECS and the wire jumpers in P1-21 and P1-22.
Turn the ECS to the STOP position.
Observe the status for the ECS on Cat ET.
Remove the wire jumper between terminal 11 of the ECS and the wire jumpers in P1-21 and P1-22.
Observe the status for the ECS on Cat ET.
Turn the ECS to the