16333 Mercury ROD SNAP

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 or 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.
The ECM will illuminate the check engine lamp. The ECM will pulse the action lamp and the action alarm at a rate of .5 Hz per second.
1627-6 Fuel Pump Relay : Current Above Normal The engine's ECM detects a short in the circuit for the fuel pump relay.
The ECM can only detect this condition when the output driver is activated. The electric fuel priming pump provides the fuel to the engine's low pressure fuel system. When the keyswitch is turned to the ON position, the ECM energizes the fuel pump relay for two minutes. The normally open contacts of the fuel pump relay close. Battery power is supplied to the electric fuel priming pump through the contacts of the fuel pump relay. If the keyswitch is turned to the OFF position and back to the ON position, the ECM will energize the fuel pump relay for another two minutes. When the engine is cranking or running the electric fuel priming pump will run continuously. The fuel pressure regulator in the electric fuel priming pump begins to limit fuel pressure at 550 kPa (80 psi).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 g01709633
Typical schematic
Illustration 2 g01141049
Typical location of the P1 ECM connectors
Illustration 3 g01709634
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 diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic code to become active.
Deactivate the override for the fuel pump relay.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 70 seconds in order for the diagnostic codes to become active.Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic codes are active, but a problem is suspected in the circuit for the fuel priming pump. Proceed to Test Step 5.
Not OK - A 6 diagnostic code is active at this time. Proceed to Test Step 2.
Not OK - A 5 diagnostic code is active at this time. Proceed to Test Step 3.Test Step 2. Create an Open at the Connector for the Fuel Pump Relay
Remove power from the ECM.
Turn the keyswitch to the OFF position.
Disconnect the connector for the fuel pump relay.
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 diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic code to become active.
Deactivate the override for the fuel pump relay.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 70 seconds in order for the diagnostic codes to become active.Expected Result:A 5 diagnostic code is now active for the fuel pump relay.Results:
OK - A 5 diagnostic code became active after disconnecting the connector.Repair: Temporarily connect a new fuel pump relay to the harness, but do not install the new fuel pump relay. Verify that there are no active diagnostic codes for the fuel pump relay. If there are no active diagnostic codes for the fuel pump relay, permanently install the new fuel pump relay. Clear any logged diagnostic codes.STOP
Not OK - A 6 diagnostic code remains active. There is a short between the connector for the fuel pump relay and the ECM. Proceed to Test Step 4.Test Step 3. Create a Short at the Connector for the Fuel Pump Relay
Remove power from the ECM.
Turn the keyswitch to the OFF position.
Disconnect the connector for the fuel pump relay. Install a jumper wire between terminal 5 and terminal 2 at the connector for the fuel pump relay. Refer to Illustration 1 for the schematic of the circuit.
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 diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic code to become active.
Deactivate the override for the fuel pump relay.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 70 seconds in order for the diagnostic codes to become active.Expected Result:A 6 diagnostic code is active when the jumper wire is installed.Results:
OK - The engine harness and the ECM are OK.Repair: Temporarily connect a new fuel pump relay to the harness, but do not install the new fuel pump relay. Verify that there are no active diagnostic codes for the fuel pump relay. If there are no active diagnostic codes for the fuel pump relay, permanently install the new fuel pump relay. Clear any logged diagnostic codes.STOP
Not OK - The 5 diagnostic code remains active with the jumper in place. Verify that wire 229-BK(Black) on terminal 2 of the connector for the fuel pump relay has continuity to engine ground. If wire 229-BK(Black)