False 444-5 Start Relay Open Diagnostic Code on 3500B Marine Propulsion Engines{1426} Caterpillar

Engine:

3508B (S/N: S2D113-UP; S2E145-UP; S2F104-UP)

3512B (S/N: S2J135-UP; S2K108-UP; S2L160-UP; S2M110-UP; S2N107-UP)

3516B (S/N: S2S140-UP; S2T100-UP; S2W102-UP; S2X178-UP; S2Y106-UP)

Introduction

The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.

Problem

Some 3500B Marine Propulsion Engines will log a false 444-5 Start Relay Open diagnostic code. The 231-9867 Panel Harness As is assembled incorrectly. The primary Electronic Control Module (ECM) monitors pin 7 on the J2 connector for return current from the starter relay coil. Wire G229-P17-BK-18 is connected to the −Battery. This results in a 444-5 Start Relay Open diagnostic code due to the open circuit on pin 7 of the J2 connector. This wire must be connected to pin 7 on the J2 connector.

Solution

Illustration 1	g01264250
(A) Incorrect wiring for wire G229-P17-BK-18

Refer to Electrical Schematic, RENR5010 for more information.

Remove wire (A) in Illustration 1. Illustration 1 shows the Starting Motor Magnetic Start (SMMS) is connected to the primary ECM breaker. Wire (A) is connected to the −Battery on the 231-9867 Panel Harness As . This will cause a 444-5 Start Relay Open diagnostic code.

Illustration 2	g01264538
(B) Correct wiring for wire G229-P17-BK-18

Install wire (B) in Illustration 2. Illustration 2 shows the correct connections for the ground circuit of the relay coil. Wire (B) needs to be rewired in order to connect to pin 7 on the J2 connector for the primary ECM. Once wire (B) is rewired, a path is provided for the return circuit of the SMMS to go back to the circuit for the starter drive. This will alleviate the false 444-5 Start Relay Open diagnostic code.