6.5L DS4 Injection Pump Fault Codes: Solenoid Closure Time

This knowledge base article addresses fault codes related to injection pump solenoid closure time in 6.5L diesel engines equipped with DS4 injection pumps. These fault codes typically indicate timing issues within the fuel delivery system that can significantly impact engine performance, fuel economy, and emissions.

The following diagnostic trouble codes (DTCs) are commonly associated with DS4 injection pump solenoid closure time issues:

• OBDI

  • DTC 35 : Fuel Solenoid Response Time Too Short

  • DTC 36 : Fuel Solenoid Response Time Too Long

• OBDII

  • P1216 : Fuel Solenoid Response Time Too Short

  • P1217 : Fuel Solenoid Response Time Too Long

The solenoid closure time is a critical parameter monitored by the Powertrain Control Module (PCM). This measurement represents the time required for the main fuel solenoid in the DS4 pump to fully close after receiving the command signal. The PCM requires a valid closure time within an acceptable window of variability to properly control injection commands and timing.

When closure time falls outside of specification parameters, the PCM sets a fault code to indicate that the mechanical system is operating out of spec and can no longer reliably control injection pulses.

1. PMD (Pump Mounted Driver) Testing

   • The PMD is often the primary culprit in closure time fault codes

   • The PMD calculates and communicates solenoid closure time to the PCM

   • A failing PMD can output incorrect closure time values even when the pump is mechanically sound

   • Test the PMD before replacing the injection pump

2. Fuel Quality Verification

   • Ensure the vehicle has clean, uncontaminated diesel fuel

   • Water, debris, or improper fuel can affect solenoid operation

   • Drain and replace fuel if contamination is suspected

3. Wiring Inspection

   • Check all wiring connections to the PMD and injection pump

   • Look for corroded terminals, damaged insulation, or loose connections

   • Test for proper voltage and ground at the PMD connector

   • Inspect the PMD harness for damage or shorting

As a first repair step, replace the Pump Mounted Driver (PMD):

1. Locate the PMD on the driver's side of the engine, mounted to the injection pump

   1. Or remote mounted location

2. Disconnect the electrical connector and mounting hardware

3. Apply thermal compound or pad to the new PMD mounting surface

4. Install the new PMD and secure all connections

5. Clear fault codes and perform a test drive

If PMD replacement does not resolve the issue, the injection pump requires replacement:

1. The main fuel solenoid on the DS4 pump and corresponding poppet valve adjustments are not end-user serviceable components

2. When internal pump components exceed wear tolerances, replacement of the entire pump assembly is necessary

3. Pump replacement should be performed by a qualified diesel technician

• Diagnostic fault codes should not be assumed valid without hands-on inspection of the vehicle

• Internal pump repair is not recommended and can lead to catastrophic engine failure

• Remanufactured pumps often provide a cost-effective alternative to new pump assemblies

• After pump replacement, the PCM may require relearning procedures to establish new baseline parameters

The DS4 injection pump relies on precise solenoid timing to control fuel delivery. The PCM constantly monitors closure time to make adjustments to injection timing, duration, and pressure. When mechanical wear, electrical faults, or component failures prevent the solenoid from operating within specification, the engine management system can no longer accurately control combustion, leading to performance issues, increased emissions, and potential engine damage if left unaddressed.

• Injection Control Pressure (ICP) sensor

• Camshaft Position (CMP) sensor

• Fuel temperature sensor

• PCM (Powertrain Control Module)

• Fuel filter assembly

Solenoid closure time specifications vary by engine model year and calibration. Refer to the appropriate service manual for exact specifications.

• Service Manual: Section 6.5L Diesel Fuel System

• Our other articles with DTC definitions and troubleshooting workflows