DTC P1689: NO COMMUNICATION BETWEEN ECM & INJECTION PUMP MODULE (OBDII)
Monitor & Set Conditions
Communication between Engine Control Module (ECM) and fuel injection pump module is monitored when ignition is on. Injection pump module is referred to as Fuel Pump Control Module (FPCM) in test procedures. DTC may be stored if the time between CAN messages is more than 3 seconds or FPCM does not receive CAN message.
Possible Causes
- Wiring & Connectors
- Fuel Injection Pump Relay Output Circuit Open
- Ground Circuit Open Or High Resistance
- Datalink (+) Circuit Open
- Datalink (+) Circuit Shorted To Ground
- Datalink (-) Open
- Datalink (-) Shorted To Ground
- ECM
Testing
1. Turn ignition on with engine off. Using DRBIII(R) scan tool, check for DTCs. If Good Trip Counter for DTC P1689 is displayed and not equal to zero, go to next step. If Good Trip Counter for DTC P1689 is displayed and equal to zero, go to step 3 .
2. Turn ignition off. At this time, conditions required for DTC to be stored are not present. Inspect wiring and connectors between FPCM and ECM. FPCM located on top of fuel injection pump. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. If no problems exist, go to next step. If any problems exist, repair wiring or connectors as necessary.
3. Ensure ignition is off. Disconnect FPCM harness connector. FPCM harness connector is located on end of fuel injection pump. Check for poor connection/terminal contact at FPCM harness connector. Repair as necessary. Turn ignition on with engine off. Using DVOM, measure voltage between ground and terminal No. 7 (Red/Light Green wire) on FPCM harness connector. If voltage is 8 volts or greater, go to next step. If voltage is less than 8 volts, perform DTC P0215: FUEL INJECTION PUMP CONTROL CIRCUIT test.
4. Turn ignition off. Ensure FPCM connector is still disconnected. Disconnect ECM harness connector. Check for poor connection/terminal contact at ECM harness connector. Repair as necessary. Connect a test light between battery voltage and terminal No. 6 (Black/Tan wire) on FPCM connector. This is the ground circuit for FPCM. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair open or high resistance on Black/Tan wire between FPCM and ground connection. Ground connection is located at ground connection for negative battery terminal.
5. Ensure ignition is off and FPCM harness connector and ECM harness connector are still disconnected. Using DVOM, measure resistance of White wire between terminal No. 2 on FPCM harness connector and terminal No. 13 on ECM harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open or high resistance in White wire between FPCM and ECM.
6. Ensure ignition is off and FPCM harness connector and ECM harness connector are still disconnected. Using DVOM, measure resistance between ground and terminal No. 2 (White wire) on FPCM connector. If resistance is 5 ohms or greater, go to next step. If resistance is less than 5 ohms, repair short to ground in White wire between FPCM and ECM.
7. Ensure ignition is off and FPCM harness connector and ECM harness connector are still disconnected. Using DVOM, measure resistance of Black wire between terminal No. 1 on FPCM harness connector and terminal No. 23 on ECM harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or greater, repair open or high resistance in Black wire between FPCM and ECM.
8. Ensure ignition is off and FPCM harness connector and ECM harness connector are still disconnected. Using DVOM, measure resistance between ground and terminal No. 1 (Black wire) on FPCM harness connector. If resistance is 5 ohms or greater, replace and program ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. If resistance is less than 5 ohms, repair short to ground in Black wire between FPCM and ECM.
