19251-ZY3-000 Honda TUBE, WATER (L) (Honda Code 6990840).

Table 1
Diagnostic Trouble Codes
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
558-2 1634-2 Accelerator Pedal 1 Low Idle Switch : Erratic, Intermittent, or Incorrect The Electronic Control Module (ECM) detects the following condition:
The signal from the Idle Validation Switch (IVS) is invalid.
If equipped, the warning light will come on. The ECM will log the diagnostic code.
2970-2 1635-2 Accelerator Pedal 2 Low Idle Switch : Erratic, Intermittent, or Incorrect
Follow the troubleshooting procedure to identify the root cause of the fault. If the application is equipped with two throttles, the engine will use the second throttle until the fault is repaired.If a second throttle is not installed or if the second throttle has a fault, the following conditions will occur:
The engine will default to limp home mode.
If the engine speed is higher than the speed in limp home mode, the engine will decelerate to limp home mode.
If the engine speed is lower than the speed in limp home mode, the engine speed will remain at the current speed.
The engine will remain at this speed whilst 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 IVS may be installed. The IVS is required for mobile applications with an analog throttle installed. The IVS is part of the throttle position sensor. The IVS is CLOSED when the low idle is set.The configuration parameters for the throttle and for the IVS thresholds are programmed into the ECM. Use the electronic service tool to display the configuration parameters for the throttle and for the IVS.If the IVS operates outside of the programmed range, then the engine speed may not respond to changes in the throttle position.The electronic service tool may be used for the following:
If necessary, reset the IVS threshold for an existing IVS.
If necessary, view the IVS change point and reset the IVS thresholds when a new throttle assembly is installed.
Illustration 1 g06385150
Schematic of the IVS circuit
Not all connectors are shown. Refer to the Electrical Schematic for the application.
Illustration 2 g06381584
Typical view of the pin locations in the P1 connector for the IVS
(35) Sensor Ground
(44) Idle validation 2
(45) Idle validation 1
Table 2
Troubleshooting Test Steps Values Results
1. Check for Active Diagnostic Codes and/or Recently Logged Diagnostic Codes
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position.
C. Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes.
Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are a poor connection in a connector.
Diagnostic codes
Result: No diagnostic codes are active - the problem may have been intermittent.
Repair: Carefully inspect the connectors and wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Result: One of the diagnostic codes listed in Table 1is active or recently logged at this time.
Proceed to Test Step 2.
2. Check the Operation of the IVS
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position.
Note: Do not start the engine.
C. Use the electronic service tool to check the current "Throttle Configuration".
D. Select the "SERVICE" option from the drop-down menu of the electronic service tool.
E. Select the "Throttle Configuration" option on the electronic service tool. Select the appropriate "Throttle Configuration" summary from the menu on the left of the screen. The IVS window for the throttle will indicate "YES" if an IVS is installed.
F. Select the "Throttle status" function on the electronic service tool. Select "Status" function and then select "Throttles" function.
G. The throttle is set in the low idle position.
H. Operate the throttle slowly. The IVS status should change from CLOSED (ON) to OPEN (OFF).
IVS status change
Result: The IVS state changes from CLOSED (ON) to OPEN (OFF)
Proceed to Test Step 3.
Result: The IVS state does not change.
Proceed to Test Step 4.
3. Check the IVS Threshold
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position.
C. Use the electronic service tool to check the current "Throttle Configuration".
D. Select the "SERVICE" option from the drop-down menu of the electronic service tool.
E. Select the "Throttle Configuration" option on the electronic service tool. Select the appropriate "Throttle Configuration" summary from the menu on the left of the screen. The IVS window for the throttle will indicate "YES" if an IVS is installed. Make a note of the "Idle Validation Min OFF Threshold" parameters that are displayed in the "Throttle Configuration" menu of the electronic service tool. Make a note of the "Idle Validation Max ON Threshold" parameters that are displayed in the "Throttle Configuration" menu of the electronic service tool.
F. To select the "Throttle status" function on the electronic service tool, select "Status" function and then select "Throttles" function.
G. The throttle is set in the low idle position.
H. Operate the throttle slowly. The IVS status should change from CLOSED (ON) to OPEN (OFF).
IVS operates within threshold.
Result: The IVS switch operates within the "Idle Validation Min OFF Threshold" and the "Idle Validation Max ON Threshold" parameters.
The IVS is operating correctly.
Return the engine to service.
Result: The IVS switch cannot operate within the "Idle Validation Min OFF Threshold" and the "Idle Validation Max ON Threshold" parameters.
Proceed to Test Step 9.
4. Inspect Electrical Connectors and the Harness
A. Inspect the P1/J1 connectors, the harness and all the connectors for the IVS. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
B. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the suspect idle validation switch.
C. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
D. Check the harness for abrasion and pinch points from the throttle switch to the ECM.
Loose connection or damaged wire
Result: Faults found in harness or connectors.
Repair: Repair