Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 1996 Ford RV Cutaway, 1996 Ford Pickup, 1996 Ford F-Super Duty, 1996 Ford Econoline, and 1996 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

1) DTC 1536 Or NGS Tester PID PBA: Determine Cause Of PBA Not Changing States

This DTC indicates that PCM does not detect a PBA state change during KOER SELF-TEST. Possible causes for this DTC are:
- Low brake fluid.
- Short to ground or power.
- Open circuit.
- Faulty Powertrain Control Module (PCM).
Start engine and observe BRAKE warning and ABS warning lights (bulb check). If both lights are on, go to next step. If one or both lights are off, repair wiring in bulb circuit(s) as necessary. After repair is completed, perform bulb check again to confirm repair.

2) Check For Brake System Problem

Turn ignition on. Ensure parking brake is fully off. Check BRAKE warning and ABS warning lights. If one or both lights are illuminated, a fault exists in brake system. Check and repair manual or ABS brake system as necessary. See appropriate ANTI-LOCK or DISC & DRUM article in BRAKES. If both lights are off, go to next step.

3) Check PBA Parameter Identification (PID)

Ensure scan tool is connected to Data Link Connector (DLC). Using scan tool, access PBA PID from PID/DATA MONITOR & RECORD menu. Observe PBA PID reading and cycle parking brake. If PBA PID reading indicates ON only, go to next step. If PBA PID reading does not indicate ON only, go to step 6).

4) Check PBA Switch

Turn ignition on. Disconnect PBA switch. If PBA PID switches to OFF, replace PBA switch. Reconnect all connectors and confirm repair using scan tool and accessing PBA PID from PID/DATA MONITOR & RECORD menu while applying and releasing parking brake. If PBA PID does not switch to OFF, go to next step.

5) Check For Short To Ground

Turn ignition off. Disconnect PCM 104-pin connector. Measure resistance between ground and Purple/White wire at PBA switch wiring harness connector. If resistance is less than 10 k/ohms, locate and repair short to ground in Purple/White wire. Reconnect all connectors and confirm repair using scan tool and accessing PBA PID from PID/DATA MONITOR & RECORD menu while applying and releasing parking brake. If resistance is 10 k/ohms or more, inspect PCM 104-pin connector for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all connectors and go to step 9).

6) Check PBA PID

Using scan tool, observe PBA PID reading. Cycle parking brake. If PBA PID reading indicates OFF only, go to next step. If PBA PID reading does not indicate OFF only, fault may be intermittent. Go to step 10).

7) Check PBA Switch

Turn ignition on. Ensure PBA switch is disconnected. Connect a jumper wire between ground and Purple/White wire at PBA switch wiring harness connector. Using scan tool, check PBA PID reading. If PBA PID reading indicates ON, replace PBA switch. Reconnect all connectors and confirm repair using scan tool and accessing PBA PID from PID/DATA MONITOR & RECORD menu while applying and releasing parking brake. If PBA PID reading does not indicate ON, go to next step.

8) Check Purple/White Wire For Open

Disconnect jumper wire. 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. Turn ignition on. Measure voltage between ground and test pin No. 4 at breakout box. If battery voltage is present, open is at terminal No. 4 at PCM. Inspect PCM 104-pin connector for damaged pins, corrosion and loose wires. Repair as necessary. Reconnect all connectors and go to next step. If battery voltage is not present, locate and repair open circuit in circuit No. 162 (Light Green/Red wire), or circuit No. 977 (Purple/White wire). Reconnect all connectors and confirm repair using scan tool and accessing PBA PID from PID/DATA MONITOR & RECORD menu while applying and releasing parking brake.

9) Confirm PCM Fault

Turn ignition on. Using scan tool, access PBA PID from PID/DATA MONITOR & RECORD menu. While observing PBA PID reading, cycle parking brake. If PBA PID switches from ON to OFF, no problem is indicated at this time. If PBA PID does not switch from ON to OFF, replace PCM. Reconnect all connectors and confirm repair using scan tool and accessing PBA PID from PID/DATA MONITOR & RECORD menu while applying and releasing parking brake.

10) Check For Intermittent Short To Ground

Ensure PBA switch is disconnected. Turn ignition on. Using scan tool, access PBA PID from PID/DATA MONITOR & RECORD menu. PBA PID reading should indicate OFF. While observing PBA PID, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (PBA PID switches from OFF to ON), isolate fault and repair as necessary. Reconnect all connectors and confirm repair using scan tool and accessing PBA PID from PID/DATA MONITOR & RECORD menu while applying and releasing parking brake. If no fault is indicated, go to next step.

11) Check For Intermittent Open

Apply parking brake. Using scan tool, access PBA PID from PID/DATA MONITOR & RECORD menu. PBA PID should indicate ON. While observing PBA PID reading, wiggle and bend small sections of wiring harness working toward PCM. If fault is indicated (PBA PID switches from ON to OFF), isolate fault and repair as necessary. Reconnect all components and confirm repair using scan tool and accessing PBA PID from PID/DATA MONITOR & RECORD menu while applying and releasing parking brake. Repeat KOER SELF-TEST under QUICK TEST. If no fault is indicated, no problem is indicated at this time. Confirm repair using scan tool and accessing PBA PID from PID/DATA MONITOR & RECORD menu while applying and releasing parking brake. Repeat KOER SELF-TEST under QUICK TEST.