858281T 1 Mariner CYLINDER HEAD

Table 1
Diagnostic Codes Table
CDL Code and Description Conditions which Generate the Code System Response
1627-5 Fuel Pump Relay current below normal The 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 ECM detects a short circuit for the fuel pump relay.
The ECM can only detect this condition when the output driver is activated. During the following scenarios ECM energizes the fuel pump relay. The fuel pump relay controls battery power to the fuel priming pump.ECM Activation of the Fuel Priming PumpThis strategy improves the capability of the fuel system at low engine speeds.The ECM will automatically activate the fuel priming pump while the engine state is CRANKING, RUNNING, or POSTRUN. The ECM deactivates the fuel pump when the engine speed is greater than 200 rpm. Manual Override of the Fuel Priming PumpUse the "Fuel Priming Pump Command Override" in Caterpillar Electronic Technician (ET) to diagnose a problem with the electric fuel priming pump. A "Fuel Priming Pump Command" parameter is also available in Cat ET that can be used to view the status of the ECM output.When the override is activated, the ECM powers the electric fuel priming pump. The ECM will command the FCV throttle position to 25 percent. Opening the FCV throttle provides a path for air to escape from the low-pressure fuel system. To use this feature, the ECM and the keyswitch relay must be powered. Also, the engine speed must be 0 rpm.
Illustration 1 g03211279
Schematic for the electric fuel priming pump
Illustration 2 g03377780
Location of the connectors at the control box for the electric fuel priming pump. (Control box may not be located on engine.)
(1) Right rail connector
(2) J1/P1 ECM connector
(3) J2/P2 ECM connector
(4) Fuel pump relay
(5) Power connector
Illustration 3 g03211296
Location of the connectors for the fuel priming pump (typical front right engine view)
(6) Connector for the electric fuel priming pump
Illustration 4 g01447112
Terminal locations for the high-pressure fuel pump at the P1 connectors (primary ECM and secondary ECM)
(P1-10) Fuel priming pump
Illustration 5 g01284152
Terminal locations for the high-pressure fuel pump at the P2 connectors (primary ECM and secondary ECM)
(P2-14) Digital return
Illustration 6 g01535537
Terminal locations at the right rail connector for the electric fuel priming pump
(Terminal 18) Return
(Terminal 19) Relay signal circuit to the pump
Illustration 7 g01535553
Terminal locations at the control box connector for the primary power harness
(Terminal 59) Relay signal circuit to the pump
(Terminal 60) Return
Illustration 8 g01533453
Terminal locations at the keyswitch relay and the relay for the power mode circuit
(Terminal 1) Battery power for the secondary circuit of the relay
(Terminal 2) Power for the control circuit of the relay
(Terminal 4) Output to the fuel priming pump
(Terminal 5) Return for the control circuit of the relay
Illustration 9 g01155187
Terminal locations at the connector for the electric fuel priming pump
(Terminal 1) Relay signal circuit to the pump
(Terminal 2) Return
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Turn the battery disconnect switch to the OFF position.
B. Thoroughly inspect connectors (1) through (8) and connector (13). Also, check the condition of breaker (12). Reset the breaker, if necessary. Refer to Troubleshooting, "Electrical Connectors - Inspect"
C. Check the torque of the allen head screws for each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
D. Check the harness and t