PAD 9P3645 - Caterpillar

System Operation Description:This procedure covers the following codes:
Table 1
Diagnostic Trouble Codes for the Circuit for the Idle Validation Switch
J1939 Code Description Notes
558-2 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 Accelerator Pedal 2 Low Idle Switch : Erratic, Intermittent, or Incorrect 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 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 IVS may be installed. The IVS is required for mobile applications. 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 in order 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 g02140710
Schematic of the IVS circuit
Illustration 2 g01981113
Typical view of the pin locations in the P1 connector for the IVS
(18) Sensor Ground
(22) Idle validation 1
(40) Idle validation 2 Test Step 1. Check for Active Diagnostic Codes and/or Recently Logged Diagnostic Codes
Connect the electronic service tool to the service tool connector.
Turn the keyswitch to the ON position.
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 the result of a poor connection between a socket and a pin in a connector or of a poor connection between a wire and a terminal.Results:
A 558-2 or a 2970-2 diagnostic code is active or recently logged at this time. - Proceed to Test Step 2.
No diagnostic codes are active - The problem may have been intermittent.Repair: Carefully inspect the connectors and wiring. Refer to