Engine Controls - Diagnostic Methods (Except Diesel & Hybrid): Other Mercury Sable V

Vehicle Check/Preparation

Before using the scan tool to carry out any test, refer to the important Safety Notice located at the beginning of this article and the necessary visual checks listed below.

Visual Checks

1. Inspect the air cleaner and inlet duct.
2. Check all engine vacuum hoses for damage, leaks, cracks, kinks, and proper routing.
3. Check the electronic engine control (EEC) system wiring harness for proper connections, bent or broken pins, corrosion, loose wires, and proper routing.
4. Check the powertrain control module (PCM), sensors, and actuators for physical damage.
5. Check the engine coolant for proper level and mixture.
6. Check the transmission fluid level and quality.
7. Make all necessary repairs before continuing with the quick test. Refer to «QUICK TEST»(ref-291245-S40499306212008072500000) .

Vehicle Preparation

1. Carry out all safety steps required to start and run vehicle tests. Apply the parking brake, place the gear selector lever firmly into the PARK position on automatic transmission vehicles or NEUTRAL on manual transmission vehicles, and block the drive wheels.
2. Turn off all electrical loads such as radios, lamps, A/C, blower, and fans.
3. Start the engine (if the engine runs) and bring it up to the normal operating temperature before running the quick test.

Generic OBD PID List

An X in the Freeze Frame column denotes both a mode 1 and mode 2 PID (real time and freeze frame).

a OL = Open loop, have not satisfied conditions for closed loop.

b Percent engine load adjusted for atmospheric pressure.

Ford PID List

Note. This is not a complete list of Ford PIDs available. This is a list of Ford PIDs in this article.

Making Changes to the VID Block

A PCM which is programmed may require changes to be made to certain VID information to accommodate the vehicle hardware. Refer to Module Reprogramming on the scan tool.

Drive Cycle Recommendations

1. Most OBD monitors complete more readily using a steady foot driving style during cruise or acceleration modes. Operating the throttle in a smooth fashion minimizes the time required for monitor completion.
2. The fuel tank level should be between 1/2 and 3/4 full with 3/4 full being the most desirable.
3. The evaporative monitor can operate only during the first 30 minutes of engine operation. When executing the procedure for this monitor, stay in part throttle mode and drive in a smooth fashion to minimize fuel slosh.
4. When bypassing the EVAP engine soak times, the PCM must remain powered (key ON) after clearing the continuous DTCs and relearning emission diagnostic information.

For best results, follow each of the following steps as accurately as possible

Recreating the Fault

Recreating the concern is the first step in isolating the cause of the intermittent symptom. A thorough investigation should start with the customer information worksheet located in the back of this article. If freeze frame data is available, it may help in recreating the conditions at the time of a malfunction indicator lamp diagnostic trouble code (MIL DTC). Listed below are some of the conditions for recreating the concern

CONDITIONS TO RECREATE FAULT

Accumulating PCM Data

PCM data can be accumulated in a number of ways. This includes circuit measurements with a digital multimeter (DMM) or scan tool parameter identification (PID) data. Acquisition of PCM PID data using a scan tool is one of the easiest ways to gather information. Gather as much data as possible when the concern is occurring to prevent improper diagnosis. Data should be accumulated during different operating conditions and based on the customer description of the intermittent concern. Compare this data with the known good data values located TYPICAL DIAGNOSTIC REFERENCE VALUES . This requires recording data in 4 conditions for comparison: 1) KOEO, 2) Hot Idle, 3) 48 km/h (30 mph), and 4) 89 km/h (55 mph).

Comparing PCM Data

After the PCM values are acquired, it is necessary to determine the concern area. This typically requires the comparison of the actual values from the vehicle to the typical values from the Section 6 TYPICAL DIAGNOSTIC REFERENCE VALUES . The charts apply to different vehicle applications (engine, model, transmission).

Analyzing PCM Data

Look for abnormal events or values that are clearly incorrect. Inspect the signals for abrupt or unexpected changes. For example, during a steady cruise most of the sensor values should be relatively stable. Sensors such as throttle position (TP), mass air flow (MAF), and RPM that change abruptly when the vehicle is traveling at a constant speed are clues to a possible concern area.

Look for an agreement in related signals. For example, if the APP1, APP2, or APP3, is changed during acceleration, a corresponding change should occur in idle air control (IAC), RPM, and SPARK ADV PID.

Make sure the signals act in proper sequence. An increase in RPM after the TP1 and TP2 is increased is expected. However, if the RPM increases without a TP1 and TP2 change, a concern may exist.

Scroll through the PID data while analyzing the information. Look for sudden drops or spikes in the values.