Parking Brake Switch Signal Lost
What does DD-70-1 mean?
The DD-70-1 (Detroit Diesel DD Series) diesel fault code means: Parking Brake Switch Signal Lost. This is a minor severity code.
Common Symptoms
- Check Engine Light / Amber Warning Lamp illuminated
- PTO / remote start inhibited
Probable Causes (Ranked by Likelihood)
- Failed parking brake switch Likely
- Harness break at switch Possible
Step-by-Step Diagnostic Procedure
Verify switch state via DDDL.
Replace switch if incorrect.
Frequently Asked Questions
What is Detroit Diesel fault code DD-70-1?
Detroit Diesel fault DD-70-1 (SPN 70 FMI 1) indicates: Parking Brake Switch Signal Lost. It is a minor-severity fault and is commonly seen on DD13/DD15/DD16 engines in Freightliner and Western Star chassis.
Can I drive my Freightliner or Western Star with fault DD-70-1?
It depends on severity. Critical and serious faults trigger derate or engine shutdown — do not continue driving. Moderate faults usually allow continued operation short-term but schedule repair to prevent cascading aftertreatment damage.
How much does it cost to fix Detroit Diesel fault DD-70-1?
Typical repair cost is $200-$900. Sensor/harness fixes fall at the low end; turbo actuator, injector, aftertreatment component, or head gasket repairs fall at the high end. Detroit DDDL software and sometimes factory parameter reset are required for proper reset.