2002 PCED OBDII-Diesel SECTION 5: Pinpoint Tests DE: Exhaust Back Pressure (EBP) Sensor DE: Introduction DE1 DIAGNOSTIC TROUBLE CODE (DTC) P0470 DTC P0470 indicates an EBP sensor malfunction was detected during KOEO On-Demand Self Test. damaged EBP sensor open signal ground damaged PCM Key on, engine off. Was EBP reading below 127 kpa (18.5 psi)? CLEAR DTC and RERUN KOEO On-Demand Self Test. If code is still present, INSTALL a new PCM. RESTORE GO to DE2. DE2 SIGNAL GROUND CIRCUIT CHECK Measure resistance from pin A circuit 359 (GY/RD) to chassis ground. CLEAR REPAIR open in signal return circuit 359 (GY/RD). RESTORE vehicle. CLEAR DTC and RETEST. DE3 CONTINUOUS DIAGNOSTIC TROUBLE CODE (DTC) P0470 Continuous DTC P0470 indicates an exhaust back pressure malfunction was detected during normal driving conditions. damaged EBP sensor damaged connection damaged PCM Observe the PID while performing the following: Grasp the vehicle harness close to the EBP sensor connector. wiggle and shake the vehicle harness while working toward the PCM. Does the EBP reading fluctuate?
ISOLATE intermittent connection problem. RESTORE GO to DE4. DE4 CONNECTOR INSPECTION Inspect connector terminals and sensor terminals for signs of poor connection or corrosion. Inspect connections at the 42-way and PCM connectors. Are all connections good? Unable to verify problem at this time. RESTORE REPAIR connection concern as required. RESTORE DE5 DIAGNOSTIC TROUBLE CODE (DTC) P0471 DTC P0471 indicates an EBP range/performance problem was detected during normal driving conditions when EBP is enabled. damaged EBP sensor plugged or restricted sensor supply tube EPR linkage or butterfly damage damaged PCM Perform KOER On-Demand Self Test. If codes are present, repair them before continuing. Road test vehicle performing hard accelerations while monitoring the PID. Does EBP increase and go above 25 psi with EBP device on? Unable to duplicate failure. RESTORE vehicle. CLEAR DTC and RETEST. GO to DE6. DE6 INSPECT FOR EXHAUST LEAKS Inspect turbo pipe, crossover pipes, and exhaust manifolds for leaks. Are exhaust leaks present? REPAIR exhaust leak. RESTORE vehicle. CLEAR GO to DE7. DE7 SENSOR SUPPLY TUBE CHECK Inspect the EBP sensor supply tube from the exhaust manifold to the sensor bracket for damage. Verify tube is not plugged or restricted.
Is tube OK? GO to DE8. INSTALL a new tube. RESTORE vehicle. CLEAR DTC and RETEST. DE8 EBP SENSOR CHECK Install ICP/EBP Adapter Cable D94T-50-A or equivalent between EBP sensor and vehicle harness. Engine running. Measure voltage between signal circuit and signal ground on ICP/EBP Adapter Cable D94T-50-A or equivalent. Accelerate engine to WOT several times. Is a minimum reading of 1.35 V present during acceleration? RESTORE vehicle. CLEAR DTC and RETEST. If code reappears INSTALL a new PCM. CLEAR DTC and RETEST. DE9 DIAGNOSTIC TROUBLE CODE (DTC) P0472 DTC P0472 indicates EBP sensor circuit low input was detected during KOEO Self Test or during continuous diagnostic monitoring. open EBP sensor circuit biased sensor/pcm short to SIGN RTN or PWR GND on EBP sensor circuit open in VREF circuit Key on, engine off. Measure voltage between pin B circuit 351 (BR/WH) on harness connector and battery ground. Was voltage reading 5 V ± 0.5? GO to DE10. REPAIR open in VREF circuit 351 (BR/WH). RESTORE DE10 SIG RTN CIRCUIT CHECK Measure resistance between pin A circuit 359 (GY/RD) and ground. GO to DE11. REPAIR open in SIG RTN circuit 359 (GY/RD). RESTORE
DE11 EBP SIGNAL CIRCUIT CHECK Install breakout box; leave PCM disconnected. Measure resistance between PCM test pin 30 and pin C circuit 553 (PK/LB) at EBP sensor harness connector. GO to DE12. REPAIR open in EBP signal wire circuit 553 (PK/LB). RESTORE DE12 VREF CIRCUIT CHECK Measure resistance between PCM test pin 90 and pin B circuit 351 (BR/WH) at EBP sensor harness connector. GO to DE13. REPAIR open in EBP VREF circuit 351 (BR/WH). RESTORE vehicle. CLEAR codes and RETEST. DE13 GROUNDED EBP SIGNAL CIRCUIT CHECK Measure resistance between PCM test pin 30 and PCM test pins 25, 91, 51, 77 and 103. Is the resistance greater than 10,000 ohms? GO to DE14. REPAIR short to ground in EBP signal wire circuit 533 (PK/LB). RESTORE vehicle. CLEAR DTCs and RETEST. DE14 CHECK FOR INTERNAL PCM SHORT ON PIN 30 Connect PCM to breakout box. Measure resistance between PCM test pin 30 and PCM test pins 25, 91, 51, 77 and 103. Is the resistance greater than 10,000 ohms? CLEAR INSTALL a new PCM. RESTORE vehicle. CLEAR DE15 DIAGNOSTIC TROUBLE CODE (DTC) P0473 DTC P0473 indicates EBP sensor circuit high input detected during KOEO On-Demand Self Test or during continuous diagnostic monitoring. biased sensor/pcm
EBP circuit shorted to VREF induce opposite DTC Key on, engine off. Perform KOEO On-Demand Self Test. Did DTC P0472 appear? CLEAR GO to DE16. DE16 CHECK SHORT TO POWER ON PIN 30 Install breakout box; leave PCM disconnected. Measure resistance between PCM test pin 30 and PCM test pins 90, 97, 71 and 55. Is the resistance greater than 10,000 ohms? INSTALL a new PCM. RESTORE vehicle. CLEAR REPAIR short to power in EBP signal circuit 553 (PK/LB). RESTORE vehicle. CLEAR DTCs and RETEST. DE17 CONTINUOUS DIAGNOSTIC TROUBLE CODE P0478 DTC P0478 indicates an excessive back pressure condition existed during normal driving. stuck EBP butterfly valve restricted exhaust plugged EBP sensor line misadjusted EPR linkage F-Series wastegate turbo may be overboosting Access PIDs MGP and RPM. Road test vehicle selecting the best gear to achieve a 2500-3000 rpm acceleration. te the highest boost pressure. This is best accomplished either climbing a hill or with the truck fully loaded. Does MGP read 18 psi for over 5 seconds? GO to KH5. GO to DE18. DE18 INSPECT BUTTERFLY TANG Visually inspect butterfly tang. Refer to Section 4A or Section 4B, Diagnostic Subroutines, Performance Diagnostic Procedures, Exhaust Restriction for exhaust back pressure regulator tang position illustration. Does tang reflect an open position?
GO to DE19. REPAIR damaged linkage or butterfly valve as required. RESTORE DE19 EXHAUST RESTRICTION CHECK Engine running. Accelerate engine to WOT while observing scan tool reading. Is EBP reading below 193 kpa (28 psi)? GO to DE20. REPAIR restricted exhaust. RESTORE vehicle. CLEAR DE20 EBP SYSTEM CHECK Engine cold. EOT below 21 C (70 F) and IAT below 7 C (45 F). Road test vehicle while monitoring EBP reading on scan tool. Observe reading while back pressure device is on. Does scan tool reading stay below 345 kpa (50 psi)? INSTALL a new PCM. RESTORE vehicle. CLEAR CHECK EPR linkage adjustment. REFER to Powertrain Group in the Workshop Manual. RESTORE vehicle. DE21 CHECK FOR BIASED EBP SENSOR te: F650/750 vehicles are not equipped with EBP. KOEO. Use WDS Tester to read EBP, MAP and BARO PIDs. Does EBP deviate from atmospheric pressure in your locale by more than 10 kpa (1.5 psi)? CONFIRM wiring and PCM are OK. If OK, INSTALL a new EBP. GO to Symptom Chart 7.