5031863 JOHNSON GASKET

Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
1627-5 Fuel Pump Relay current below normal The engine's Electronic Control Module (ECM) detects an open circuit at the fuel pump relay for 60 seconds.
The ECM detects a short to battery voltage for the fuel pump relay for 60 seconds.
The ECM can only detect this condition when the output driver is not activated. The code is logged.
1627-6 Fuel Pump Relay current above normal The engine's ECM detects a short circuit for the fuel pump relay.
The ECM can only detect this condition when the output driver is activated. The ECM has the ability to energize the fuel pump relay. The fuel pump relay controls battery power to the fuel priming pump.A test on Caterpillar Electronic Technician (ET) allows the technician to energize the fuel pump relay. The test is functional when engine speed is 0 rpm. The ECM will energize the output for the fuel pump relay for 120 seconds. The test is accessed by selecting the following menus on Cat ET:
"Diagnostics"
"Diagnostic Tests"
"Override Parameters"
Illustration 1 g01302442
Typical schematic
Illustration 2 g01141049
Typical location of the P1 ECM connectors
Illustration 3 g01302446
P1 ECM connector
(P1-19) Fuel pump relay
Illustration 4 g01149844
Terminal locations of the fuel pump relay
Test Step 1. Check for Active Diagnostic Codes
Connect Cat ET to the service tool connector.
Restore power to the ECM.
Turn the keyswitch to the ON position.
Select diagnostic tests from Cat ET.
Select the "Override Parameters" screen on Cat ET.
Activate the override for the fuel pump relay.
Monitor the active