VP44

Common DTC Codes Associated with VP44 Diagnosis

• P0216 (Fuel Injection Pump Timing Failure) - This code has often been misunderstood as the VP44 “Code of Death". It does not automatically mean the VP is bad. Low lift pump pressure and misaligned keyway can also set this code. If a customer has good fuel pressure and keyway alignment has been confirmed, look to VP being bad
• P0251 and P0253 (Fuel Injection Pump Fuel Valve Failure) - The fuel solenoid on the VP is bad. This is an internal failure of the VP44.
• P0336 (Crank Shaft Position Sensor Signal) - This code is associated with the 1998.5 and 1999 Trucks because these were the only years with Crank Position sensors. CKP sensor failures are very common in these year trucks and can cause a no start, hard start, or even an erratic idle. Verify crank signal with a handheld scanner before condemning the VP44
• P1688 (Internal Fuel Pump Controller Failure) - This code usually means bad PSG (Pump Computer) on the VP44 and can most of the time be considered a VP failure.
• P1689 (No Communication Between ECM and Injection Pump Controller) - This is usually a sign of PSG failure on the pump, but the customer also needs to check to the wire between ECM and Pump controller to make sure signal is reaching the pump. Also, faulty fuel pump relay can cause this code. Please swap fuel pump relay with horn relay in the fuse panel and see if the truck will run.
• P1690 (Fuel Injection Pump does not agree with ECM CKP Sensor) - on 1998.5 and 1999 trucks suspect faulty Crank Position Sensor. If CKP signal is good, suspect faulty VP44.
• P1691 (Fuel Injection Pump Controller Calibration Error) - Faulty VP44. Pump computer is faulty which will require VP44 replacement.