PINPOINT TEST J: NO COMMUNICATION WITH THE 4x4 MODULE (PCM)
WARNING: This page is about a different car, the 2005 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.
- J1 CHECK FOR DIAGNOSTIC TOOL COMMUNICATION WITH THE VEHICLE
- Verify diagnostic tool communication with the vehicle.
- If using the using WDS, follow the directions and carry out the network test.
- If using NGS, verify that the correct cable is used and the vehicle and engine selection information is correct.
- WDS: Does the network test pass for the PCM?
NGS: Does the diagnostic tool communicate with the PCM?
- Yes : GO to J2.
- No : REFER to the appropriate diagnostic tool manual for further diagnosis.
- Verify diagnostic tool communication with the vehicle.
- J2 CHECK FOR VOLTAGE INPUT TO THE 4x4 MODULE (PCM)
- Disconnect: 4x4 Module (PCM) C175b.
- Measure the voltage between C175b-12, circuit 1861 (RD), harness side and ground; and between C175b-13, circuit 1865 (WH/OG) and ground.
- Are the voltages greater than 9 volts?
- Yes : GO to J6.
- No : GO to J3.
- J3 CHECK THE POWER DISTRIBUTION JUNCTION BOX (PDJB) MINI-FUSES
- Check PDJB mini-fuses 20 (15A) and 29 (15A).
- Are the fuses okay?
- Yes : GO to J4.
- No : CHECK circuit 1861 (RD) and circuit 1865 (WH/OG). REPAIR as necessary. REPEAT the self-test.
- J4 CHECK FOR BATTERY VOLTAGE FROM THE JUNCTION BOX (JB)
- Key in ON position.
- Measure the voltage between JB input side fuse cavity 20 and ground; and between JB input side fuse cavity 29 and ground.
- Are the voltages greater than 9 volts?
- Yes : REPAIR or INSTALL new components as necessary. REPEAT the self-test.
- No : GO to J5.
- J5 CHECK THE BATTERY VOLTAGE WITH THE ENGINE RUNNING
- Start the engine. Measure the battery voltage at the positive battery terminal.
- Is the voltage greater than 9 volts?
- Yes : REPAIR circuit 1861 (RD) or 1865 (WH/OG). REPEAT the self-test.
- No : CHECK the charging system. REFER to CHARGING SYSTEM - GENERAL INFORMATION .
- J6 CHECK THE GROUND CIRCUITS FOR AN OPEN
- Disconnect the battery ground cable. Refer to BATTERY, MOUNTING AND CABLES .
- Disconnect: 4x4 Module (PCM) C175b.
- Measure the resistance between C175b-66, circuit 567 (LB/YE) and ground; and between C175b-67, circuits 570a C175b-68, circuit 570b C175b-69, circuits 570c C175b-70 circuit 570d, (BK/WH) and ground.
- Are the resistances less than 5 ohms?
- Yes : GO to J7.
- No : REPAIR the affected circuit(s). REPEAT the self-test.
- J7 CHECK THE VOLTAGE ON GROUND CIRCUITS
- Measure the voltage between C175b-66, circuit 567 (LB/YE) and ground; and between C175b-67, circuit 570a, C175b-68, circuit 570b, C175b-69, circuit 570c, C175b-70, circuit 570d and ground.
- Is voltage present?
- Yes : REPAIR the affected circuit(s). REPEAT the self-test.
- No
: Disconnect all 4x4 module (PCM) connectors. CHECK for corrosion, and/or pushed-out pins. The condition may have been caused by a loose or corroded connector. REPAIR or CLEAN as necessary.
If not, INSTALL a new 4x4 module (integral to the PCM). REFER to ELECTRONIC ENGINE CONTROLS . TEST the system for normal operation.