Jake Brake solenoid circuit Detroit Service Manual

This Jake Brake solenoid circuit guide is the Detroit DD Series SPN 3597 FMI 3 fault-code procedure for EPA10 and GHG14 engines, where proportional valve bank 1 reads failed high. It documents the voltage checks made at the Motor Control Module.

Official document details

Brand	Detroit
Model coverage	Detroit DD Series (EPA 2007-Current)
System / group	DD Series / DTCs
SPN	3597
FMI	3
Condition	proportional valve bank 1 circuit failed high
Emissions level	EPA10 and GHG14
Source	Detroit Power Service Literature
Pages	1
File size	0.2 MB
Format	PDF
Language	English

Jake Brake solenoid circuit checks

With the MCM 120-pin connector disconnected and the ignition on, you measure voltage at pin 66 and then pin 91 against ground. Voltage above 11.5 volts at pin 66 points to a short to power from the front engine brake solenoid, while voltage at pin 91 points to a short from the rear brake solenoid. If no voltage is present at either pin, the Motor Control Module is replaced.

Fault description: proportional valve bank 1 circuit failed high
Monitored parameter and verification data
Steps 1 to 3 – Disconnect MCM, ignition on, pin 66 voltage
Step 4 – Voltage at MCM pin 91
Replace the Motor Control Module if no voltage

Applicable truck models

This fault code applies to Detroit DD Series diesel engines on the EPA10 and GHG14 calibration that use a Motor Control Module and front and rear engine brake solenoids. The removal step references Detroit Power Service Literature; confirm the pinout on the official Detroit Diesel website.

Who needs this Jake Brake solenoid circuit manual

Diesel technicians and workshop owners who see bank 1 pulled high on a Detroit engine use this sheet to check the front and rear engine brake solenoid feeds for a short to power before replacing the Motor Control Module.

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