2009/04/13 Caterpillar

Engine:

G3508 (S/N: CAW1-UP; 4WD1-UP; 2JF1-UP; 2TJ1-UP; GSF1-UP; GSG1-UP; 9TG1-UP; GSH1-UP; A3J1-UP; CPJ1-UP; GSJ1-UP; A3K1-UP; WPM1-UP; WPN1-UP; DLR1-UP; CPS1-UP; 9AW1-UP; CPY1-UP)

G3512 (S/N: 4KC1-UP; 5JD1-UP; 7NJ1-UP; 6JW1-UP; A3N1-UP; CRN1-UP; CSP1-UP; GSP1-UP; WPP1-UP; 9FP1-UP; GSR1-UP; WPR1-UP; A3S1-UP; GNS1-UP; A3T1-UP; GST1-UP; CTM1-UP)

G3512C (S/N: GHB1-UP)

G3512E (S/N: SSR1-UP)

G3516 (S/N: 3RC1-UP; 4EK1-UP; 5PN1-UP; ZBA1-UP; 8LD1-UP; CPG1-UP; WPS1-UP; WPT1-UP; A3W1-UP; GSW1-UP; WPW1-UP; 8PW1-UP; A3X1-UP; GSX1-UP; A3Y1-UP; GSY1-UP; CSZ1-UP; ZAZ1-UP; CTL1-UP)

G3516B (S/N: 7EZ1-UP; ZBB1-UP; CSC1-UP; ZBC1-UP; CME1-UP; JEF1-UP; CEY1-UP; CTW1-UP)

G3516C (S/N: GSB1-UP; TJB1-UP; GZC1-UP; TJC1-UP; GZZ1-UP; RWA1-UP; DKR1-UP)

G3516E (S/N: GAS1-UP; SLY1-UP)

G3520 (S/N: 5XW1-UP)

G3520B (S/N: TPC1-UP; CWD1-UP; GLF1-UP; GZP1-UP; GET1-UP; BGW1-UP; CTK1-UP)

G3520C (S/N: GZA1-UP; HEA1-UP; GZB1-UP; HEB1-UP; MAD1-UP; GZJ1-UP; GZK1-UP; GZL1-UP; GZM1-UP; GZN1-UP; B9P1-UP; RLP1-UP; LGS1-UP; HAT1-UP; CWW1-UP; CWY1-UP; GDB1-UP; GHE1-UP; JBX1-UP; JBZ1-UP)

G3520E (S/N: GZG1-UP; GZH1-UP; HAL1-UP; SXY1-UP; GHM1-UP; GHR1-UP)

G3606 (S/N: 3XF1-UP; 4ZS1-UP)

G3608 (S/N: 4WF1-UP; BEN1-UP)

G3612 (S/N: 1YG1-UP; BKE1-UP)

G3616 (S/N: 4CG1-UP; BLB1-UP)

The following steps describe the sequence of a normal stop.

1. The Electronic Control Module (ECM) commands the Gas Shutoff Valve (GSOV) to close so that the engine will burn all the remaining fuel and shutdown.

   1. If the engine speed drops by more than 100 rpm within the "Drop Time" period, the stop is considered typical. The ECM will stop the ignition once the engine speed is less than 40 rpm.

2. There is a backup strategy in the software that is designed to respond when GSOV remains open or the GSOV does not fully close.

   1. In this situation, the ECM will log a "17-12" diagnostic code, and the ECM will turn off the ignition if the engine does not slow down within a set amount of time after the stop command.

   2. The logic is triggered within the "Drop Time". This event takes place as the programmable parameter that begins with the request for a shutdown has timed out and the engine rpm has not been reduced by a minimum of 100 rpm.

If the setting for deceleration of the engine speed is quick enough, making a change in the command for the desired speed may cause the engine speed to drop within the "Drop Time" period.

This can defeat the logic of the backup strategy, which means that a real failure in the GSOV could result in a engine ECM that is not logging a diagnostic and not disabling the ignition.

Note: The emergency stop will always shut down the engine because the emergency stop cuts the ignition.

Do not change the command for the desired speed after a normal stop has been requested.