16023-ZW1-000 Honda CHAMBER SET, FLOAT (Honda Code 5171871).

Table 1
Diagnostic Trouble Codes for the Analog Throttle Position Sensor Circuit
J1939 Code Description Notes
91-3 Accelerator Pedal Position 1 : Voltage Above Normal The Electronic Control Module (ECM) detects that the setting for the upper diagnostic limit has been exceeded for at least 0.5 seconds.
The keyswitch has been ON for at least 2 seconds.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
29-3 Accelerator Pedal Position 2: Voltage Above Normal
91-4 Accelerator Pedal Position 1 : Voltage Below Normal The ECM detects that the setting for the lower diagnostic limit has been exceeded for at least 0.5 seconds.
The keyswitch has been ON for at least 2 seconds.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
29-4 Accelerator Pedal Position 2: Voltage Below Normal If a fault occurs with the primary throttle with secondary throttle is installed, the secondary throttle will be used until the fault is repaired.If a fault occurs with the secondary throttle, the engine will use the primary throttle until the fault is repaired.If a functional throttle is not available, the following conditions will occur:
The engine will default to the limp home speed.
If the engine speed is higher than the limp home speed, the engine will decelerate to the limp home speed.
If the engine speed is lower than the limp home speed, the engine speed will remain at the current speed.
The engine will remain at this speed while the diagnostic code remains active.
All inputs from the faulty throttle are ignored by the ECM until the fault is repaired.
All inputs from the repaired throttle will be ignored by the ECM until the keyswitch has been cycled.The diagnostic codes above relate to an analog sensor. Use this procedure only if the analog sensor uses an output from a variable resistor.The sensor is most likely to be mounted on a throttle pedal. The sensor is attached directly to the throttle assembly. The sensor provides an output voltage to the ECM. The sensor output voltage will vary with the position of the throttle. Foot operated or hand operated throttle assemblies are available.The sensor receives +5 VDC power from the ECM. The sensor will produce a raw signal voltage that will alter between low idle and high idle. The voltage is changed into a throttle position within the range 0% to 100% by the ECM.The sensor senses the speed requirement from the throttle position. A second sensor may override this speed requirement from the first sensor. This override will be subject to an input from a secondary throttle or from the SAE J1939 (CAN) data link or from a PTO control.Use the electronic service tool in order to check the input status.Note: The identification letters for the terminals in the connectors may vary dependent on the manufacturer of the throttle pedal. Substitute the correct letters/numbers as required.
Illustration 1 g03230900
Schematic of the analog throttle position sensors
Illustration 2 g03230981
Typical example of the P1 pin locations for the analog throttle position sensors
(46) Throttle 1 - ground
(47) Throttle 1 - position
(50) Throttle 1 - 5 VDC supply
(51) Throttle 2 - 5 VDC supply
(66) Throttle 2 - ground
(67) Throttle 2 - position Test Step 1. Check for Connector Damage
Turn the keyswitch to the OFF position.
Check the connectors and the harness for the following faults: damage, abrasion, corrosion and incorrect attachment.
Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the harness that are associated with the throttle position sensor. Check the wire connectors at the ECM and at the throttle sensor. The wire connectors are shown in Illustration 1.
Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in). Expected Result:The connectors and the harness should be free of the following faults: damage, abrasion, corrosion and incorrect attachment.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 2. Check for Active Diagnostic Codes
Turn the keyswitch to the ON position.
Use the electronic service tool to check for diagnostic codes. Expected Result:One or more of the diagnostic codes that are listed in Table 1 is active or recently logged.Results:
One or more of the preceding diagnostic codes is active or recently logged. - Proceed to Test Step 5.
There are no active or recently logged diagnostic codes for the analog throttle position sensors. - Proceed to Test Step 3.Test Step 3. Check the Throttle Position with the Electronic Service Tool
Connect the electronic service tool to the diagnostic connector.
Turn the keyswitch to the ON position. Do not start the engine.
Observe the throttle position reading on the electronic service tool.
Operate the throttle over the full range of movement. Expected Result:The output should increase when the throttle is increased.The output should be between "20 percent" and "27 percent" at the low idle position. The output should be between "80 percent" and "87 percent" at the high idle position.Results:
OK - The sensor is operating correctly. Proceed to Test Step 4.
Not OK - The ECM is not receiving a correct signal from the sensor.Repair: Use the electronic service tool to verify that the throttle has been configured correctly before continuing with this procedure. For information on the parameters that can be configured, refer to Troubleshooting, "Throttle Setup"If the fault is still present after the throttle has been configured correctly, replace the analog throttle position sensor.STOPTest Step 4. Check the Throttle Selection Status with the Electronic Service Tool
Check the status of the throttle selection switch (if equipped). Use the electronic service tool in order to check the status of the throttle selection switch. Expected Result:If the status of the throttle selection switch is shown in the OFF position, then the throttle 1 has control of the engine speed.If the throttle selection switch status is shown in the ON position, then the throttle 2 has control of the engine speed.The