DTC P0606: Inactive Background Fault Ford Econoline E350

This DTC indicates an internal failure of PCM. If any other DTCs are present, service other DTCs before continuing with this test. If DTC P0606 is still present after servicing other DTCs, replace PCM. Clear DTCs and repeat QUICK TEST . If DTC P0606 is not present, no problem is indicated at this time.

Diagnostic Aids

Perform this test only when directed by QUICK TEST or if no DTCs are present and Auxiliary Powertrain Control Module (APCM) does not control engine RPM. Auxiliary powertrain control system provides an operator interface to the drive-by-wire powertrain control system to effect charge protection, RPM control and manual throttle control between 1300-2500 RPM. This test is intended to diagnose

1. Wiring harness circuits (KEY PWR, GND, BUS (+), BUS (-) and hi-mount brakelight).
2. Auxiliary Powertrain Control Module (APCM).

Enabling conditions

1. Parking brake set, transmission in Park (A/T). Service brake, accelerator pedal and brakelights must be functional. To operate system with hazard flashers, hi-mount brakelight circuit must be complete and operational.

Error DTCs are displayed from APCM only. (Scheme 314) Identify DTC and perform appropriate procedure or test step

1. If APCM is inoperative at all times, go to step 1).
2. On all models except Cutaway, if APCM is inoperative with hazard flashers, go to step 7).
3. On Cutaway models, if APCM is inoperative with flashers on, go to step 11).
4. If APCM DTC CErr or CrSD is displayed, go to step 5).
5. If APCM DTC EErr or AErr is displayed, replace APCM.

Identifying Auxiliary Powertrain Control Module (APCM). Scheme 314

Identifying Auxiliary Powertrain Control System Circuits. Scheme 315

Identifying Brake Circuit. Scheme 316

1. 1) Verify Operation Procedure Refer to auxiliary powertrain control manual provided with system to verify correct operating procedures and entry conditions. If entry conditions are met, go to next step. If entry conditions are not met, correct operating procedure. Retest system. If system still does not operate, go to next step.
2. 2) Check For DTCs Ensure auxiliary powertrain control system is off. Using NGS scan tool, perform «KOEO ON-DEMAND SELF-TEST»(ref-24260-S24365487942001010400000) , «KOER ON-DEMAND SELF-TEST»(ref-24260-S27861546292001010400000) and «KOER SWITCH SELF-TEST»(ref-24260-S25680769062001010400000) . Retrieve DTCs. If any DTCs are present, service DTCs as necessary. If no DTCs are present, go to next step.
3. 3) Check KEY PWR Voltage Disconnect APCM connector. Connector is located behind left side of instrument panel. Turn ignition on. Measure voltage between ground and terminal No. 2 at APCM wiring harness connector. If battery voltage is present, go to next step. If battery voltage is not present, locate and repair open in KEY PWR circuit.
4. 4) Check Ground Circuit Turn ignition off. Measure resistance between ground and terminal No. 1 (Black wire) at APCM wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in Black wire.
5. 5) Check For Open In BUS (-) Circuit Measure resistance of Pink/Light Blue wire between terminal No. 3 at APCM wiring harness connector and Data Link Connector (DLC). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in BUS (-) circuit.
6. 6) Check For Open In BUS (+) Circuit Measure resistance of Tan/Orange wire between terminal No. 4 at APCM wiring harness connector and Data Link Connector (DLC). If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in BUS (+) circuit.
7. 7) APCM Inoperative With Hazard Flashers (Except Cutaway Models) Turn ignition off. Depress brake pedal. If hi-mount brakelight is on, go to «CIRCUIT TEST K»(ref-24260-S07595746022001010400000) . If hi-mount brakelight is off, go to next step.
8. 8) Check Hi-Mount Brakelight Remove and inspect hi-mount brakelight bulb. Replace bulb as necessary and retest system operation. If bulb is okay, go to next step.
9. 9) Check Ground Circuit Measure resistance of Black wire between ground and hi-mount brakelight bulb socket. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in ground circuit.
10. 10) Check For Power To Bulb Turn ignition off. Depress brake pedal. Measure voltage between ground and Light Green wire at hi-mount brakelight bulb socket. If battery voltage is present, check for loose connection in bulb socket. Repair as necessary. If battery voltage is not present, repair open circuit.
11. 11) APCM Inoperative With Hazard Flashers (Cutaway Models) Turn ignition off. Disconnect brake resistor. Resistor is located on left side "B" pillar. Measure resistance of Black wire between ground and resistor connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in ground circuit.
12. 12) Check Power To Resistor Depress brake pedal. Connect a test light between ground and Light Green wire at resistor connector. If test light is on, go to next step. If test light is off, locate and repair open circuit in Light Green wire.
13. 13) Check Resistor Measure resistance between resistor terminals. If resistance is 130-150 ohms, reconnect resistor and go to «CIRCUIT TEST K»(ref-24260-S07595746022001010400000) . If resistance is not 130-150 ohms, replace resistor. Recheck system operation.

Perform this test only when directed by QUICK TEST or if no DTCs are present and tachometer is inoperative. This test is intended to diagnose

Scheme 317

1. Wiring harness circuits (KEY PWR, GND and TACH signal).
2. Tachometer. (Scheme 317): Identifying Tachometer Circuit

1. 1) Check Fuse Remove and inspect fuse No. 17 in instrument panel fuse block. If fuse is blown, locate and repair short to ground in Red/Yellow wire (circuit No. 640). Replace fuse. If fuse is okay, go to next step.
2. 2) Check Ground Circuit Turn ignition off. Disconnect instrument cluster Black 14-pin connector and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Measure resistance between ground and terminal No. 3 at instrument cluster wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open in ground circuit (Black wire).
3. 3) Check Power To Tachometer Turn ignition on. Measure voltage between ground and terminal No. 13 (Red/Light Green wire) at instrument cluster wiring harness connector. If battery voltage is present, go to next step. If battery voltage is not present, locate and repair open in Red/Light Green wire.
4. 4) Check Signal Circuit Connect New Generation Star (NGS) scan tool to Data Link Connector (DLC). Connect a jumper wire between terminal No. 3 (Black wire) at instrument cluster wiring harness connector and COM port at NGS scan tool. Connect another jumper wire between terminal No. 9 (White/Pink wire) at instrument cluster wiring harness connector and SIG port at NGS scan tool. Start engine. Using NGS scan tool, perform the following: Select VEHICLE and ENGINE. Select DIGITAL MEASUREMENT SYSTEM. Select FREQUENCY METER. Change level to 4 volt DC. Press LINK button to select a PID. Select PID/DATA MONITOR. Select RPM PID. Press START. Observe PID reading at specified engine RPM. See RPM PID FREQUENCY SPECIFICATIONS table. If frequency is as specified, inspect instrument cluster printed circuit board for damage or open circuits. Repair as necessary. If printed circuit board is okay, replace tachometer. If frequency is not as specified, go to next step. RPM PID FREQUENCY SPECIFICATIONS RPM Hz 650 119-139 1500 290-310 3000 590-610
5. 5) Check For Open In TACH Signal Circuit Turn ignition off. Disconnect PCM 104-pin connector, and inspect for damaged pins, corrosion and loose wires. Repair as necessary. Install Breakout Box (014-00950), leaving PCM disconnected. Measure resistance between terminal No. 9 (White/Pink wire) at instrument cluster wiring harness connector and test pin No. 50 (Federal models) or test pin No. 19 (Calif. models) at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, locate and repair open circuit in White/Pink wire.
6. 6) Check For Short To Ground Measure resistance between ground and test pin No. 50 (Federal models) or test pin No. 19 (Calif. models) at breakout box. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, locate and repair short to ground in White/Pink wire.
7. 7) Check For Short To Power Turn ignition on. Measure voltage between ground and test pin No. 50 (Federal models) or test pin No. 19 (Calif. models) at breakout box. If battery voltage is present, locate and repair short to power in White/Pink wire. If battery voltage is not present, replace PCM.