Part 2

Instrument Panel Cluster (IPC)

System Operation

Fuel Gauge

The IPC (Instrument Panel Cluster) sends a reference voltage to the fuel level sender(s). As the fuel level changes, a float actuates the variable resistor fuel level sender, raising or lowering the fuel level signal voltage. The IPC (Instrument Panel Cluster) monitors the changes in voltage from both senders and commands the fuel gauge with a corresponding movement of the pointer.
The IPC (Instrument Panel Cluster) interprets both inputs and uses 4 different operating modes to calculate the fuel level:

- Anti-slosh (default mode)
- Key OFF fueling
- Key ON fueling
- Recovery
After a fuel fill up, the time for the fuel gauge to move from empty (E) to full (F) ranges from 2 seconds to 55 minutes depending on which operating mode the fuel gauge is in.

Anti-Slosh Mode

The default fuel gauge mode is called the anti-slosh mode. To prevent fuel gauge changes from fuel slosh (gauge instability due to changes in fuel sensor readings caused by fuel moving around in the tank), the fuel gauge takes approximately 55 minutes to go from empty (E) to full (F).

Key OFF Fueling Mode

The key OFF fueling mode (2 seconds to read empty [E] to full [F]) requires the following conditions be met:
- The ignition must be OFF when refueling the vehicle.
- At least 15% of the vehicle's fuel capacity must be added to the fuel tank.
- The IPC (Instrument Panel Cluster) must receive a valid key ON fuel sensor reading within one second of the ignition being put into RUN. The key ON sample readings are considered valid if the fuel sensor reading is between 10 ohms± 2 ohms and 180 ohms± 4 ohms.

If these conditions are not met, the fuel gauge stays in the anti-slosh mode, which results in a slow to read full (F) event.

Key ON Fueling Mode

The key ON fueling mode (approximately 60 seconds to read empty [E] to full [F]) requires the following conditions be met:
- The transaxle is in PARK or NEUTRAL.
- The ignition is in RUN.
- At least 15% of the vehicle's fuel capacity must be added to the fuel tank.

In key ON fueling mode, a 30 second timer activates after the transaxle is put into the PARK or NEUTRAL position. When the 30 second time has elapsed and at least 15% of the vehicle's fuel capacity has been added, the fuel gauge response time is 60 seconds to read from empty (E) to full (F). When the transaxle is shifted out of PARK or NEUTRAL, the fuel gauge strategy reverts to the anti-slosh mode. The key ON fueling mode prevents slow to read full events from happening if the customer refuels the vehicle with the ignition in RUN.

Recovery Mode

Recovery mode is incorporated into the IPC (Instrument Panel Cluster) strategy to recover from a missing fuel level input after a refueling event. Missing fuel level inputs result from intermittent opens in the fuel sensor or its circuits. Recovery mode (empty [E] to full [F] approximately 20 minutes) is initiated when the following conditions are met:
- The IPC (Instrument Panel Cluster) is in the anti-slosh (default) mode.
- The actual fuel level in the tank is greater than what is being displayed by the fuel gauge.

Temperature Gauge

The temperature gauge is located in the LCD (Liquid Crystal Display) display area and is a graphical image as opposed to the more traditionally recognized analog gauge. The base IPC (Instrument Panel Cluster) uses a thermometer style image that moves upward as the engine temperature increases, changing color as the temperature reaches predetermined ranges. When the temperature is in the cold band, the thermometer color is blue. When the temperature is in the normal band, the thermometer color is gray and when the temperature is in the hot band, the thermometer color is red.
The optional IPC (Instrument Panel Cluster) uses a more traditional gauge image with a single bar set horizontally across the gauge and moves vertically from bottom to top as the engine temperature increases.
The PCM (Powertrain Control Module) uses the CHT (Cylinder Head Temperature) sensor to measure the engine temperature. The IPC (Instrument Panel Cluster) uses the engine coolant temperature message from the PCM (Powertrain Control Module) to control the temperature gauge indication.

Tachometer

The PCM (Powertrain Control Module) uses the CKP (Crankshaft Position) sensor to measure the engine RPM (Revolutions Per Minute). The IPC (Instrument Panel Cluster) uses the engine RPM (Revolutions Per Minute) data message from the PCM (Powertrain Control Module) to control the tachometer.
The base and optional IPC (Instrument Panel Cluster) tachometers appear differently but function the same. The base IPC (Instrument Panel Cluster) uses an analog gauge. The optional IPC (Instrument Panel Cluster) uses a digital display that provides a 6,000 RPM (Revolutions Per Minute) bar graph or a simulated 7,000 RPM (Revolutions Per Minute) analog gauge display depending on the selected display mode.

Speedometer

The PCM (Powertrain Control Module) calculates the vehicle speed from the transaxle OSS (Output Shaft Speed) sensor input and from the tire size and axle ratio configuration in the PCM (Powertrain Control Module) VID (Vehicle Identification) block. The PCM (Powertrain Control Module) provides the IPC (Instrument Panel Cluster) with a vehicle speed data message to command the speedometer pointer.
The IPC (Instrument Panel Cluster) provides a tolerance which allows the gauge to display between 3% lower and 7% higher than the actual vehicle speed. This means that with an actual vehicle speed of 96.6 km/h (60 mph), the speedometer may indicate between 93.7 km/h (58.2 mph) and 103.3 km/h (64.2 mph), which is normal.

Odometer

The IPC (Instrument Panel Cluster) receives the odometer count message from the PCM (Powertrain Control Module). The IPC (Instrument Panel Cluster) monitors the odometer count input from the PCM (Powertrain Control Module) and commands the odometer with a digital display in the message center.

Brake Warning Indicator

The IPC (Instrument Panel Cluster) uses 3 basic messaged inputs to control the brake warning indicator. The first two messages are the parking brake position switch and the brake fluid level switch sent from the BCM (Body Control Module). The third is the EBD (Electronic Brake Distribution) message sent from the ABS (Anti-Lock Brake System) module.
The parking brake position switch is hardwired to the BCM (Body Control Module) through a single signal circuit while using a separate ground to control the input. The brake fluid level switch is hardwired to the BCM (Body Control Module) through separate signal and return circuits to control the input.
The BCM (Body Control Module) provides battery reference voltage to both the parking brake position switch and the brake fluid level switch. When the parking brake is applied, the parking brake position switch closes to ground, pulling the parking brake signal circuit low. When a low brake fluid level condition exists, the brake fluid level switch closes to ground, pulling the signal and return circuits low. If the brake fluid level switch is disconnected, the BCM (Body Control Module) reference voltage sent to the brake fluid level switch is sent high. When the BCM (Body Control Module) detects either the brake fluid level signal or the parking brake signal circuits low, or the brake fluid level signal and return circuit high, the BCM (Body Control Module) sends the IPC (Instrument Panel Cluster) a brake warning indicator request.
When the ABS (Anti-Lock Brake System) module detects a base brake system concern or other ABS (Anti-Lock Brake System) related concerns that affect the EBD (Electronic Brake Distribution) function, the ABS (Anti-Lock Brake System) module sends a brake (red) warning indicator request to the IPC (Instrument Panel Cluster) to illuminate the brake warning indicator and the ABS (Anti-Lock Brake System) warning indicator.

ABS Warning Indicator

The IPC (Instrument Panel Cluster) uses a ABS (Anti-Lock Brake System) warning indicator request from the ABS (Anti-Lock Brake System) module to control the ABS (Anti-Lock Brake System) warning indicator. If a fault condition exists in the ABS (Anti-Lock Brake System), the ABS (Anti-Lock Brake System) module sends the IPC (Instrument Panel Cluster) the ABS (Anti-Lock Brake System) warning indicator request to either flash or illuminate the ABS (Anti-Lock Brake System) warning indicator.

Stability-Traction Control Indicator (Sliding Car Icon)

The IPC (Instrument Panel Cluster) uses a traction control indicator request message from the ABS (Anti-Lock Brake System) module to control the stability-traction control indicator (sliding car icon). The stability-traction control indicator (sliding car icon) flashes when the vehicle stability-traction control is in active mode or is being controlled by the ABS (Anti-Lock Brake System) module. The stability-traction control indicator (sliding car icon) illuminates continuously if a fault condition exists in the stability-traction control system. The IPC (Instrument Panel Cluster) monitors the traction control indicator request message from the ABS module and either flashes the stability-traction control indicator (sliding car icon) or illuminates it steady depending on the condition.

Stability-Traction Control Disabled Indicator (Sliding Car OFF Icon)

The stability-traction control is configured on/off through the message center. When the stability-traction control is configured on or off, the IPC (Instrument Panel Cluster) sends a message to the ABS (Anti-Lock Brake System) module indicating the stability-traction control system has been enabled or disabled by the driver. The ABS (Anti-Lock Brake System) module either enables or disables the stability-traction control system and sends a traction control disabled (OFF) indicator request back to the IPC (Instrument Panel Cluster) to illuminate or turn off the stability/traction control disabled indicator (sliding car OFF icon) based upon the system state. The stability/traction control system defaults back on or enabled once the ignition is cycled off then back on again.
When a MyKey(R) programmed key is in use and the AdvanceTrac(R) on feature is configured always on, the traction control system cannot be disabled and the stability-traction control disabled indicator (sliding car OFF icon) does not illuminate when the traction control disable button is pressed. The stability-traction control indicator still functions normally to indicate a stability-traction control system fault and a stability-traction control active event.

LH-RH Turn Signal Indicator

When the multifunction switch is in the LH (Left Hand) or RH (Right Hand) turn position or if the hazard switch is on, a turn indicator command message is sent to the IPC (Instrument Panel Cluster) from the BCM (Body Control Module). Upon receipt of the applicable turn signal on/off request, the IPC (Instrument Panel Cluster) flashes the turn signal indicator on and off.

High Beam Indicator

When the high beams are turned on, the BCM (Body Control Module) sends a headlamp high beam indicator request to the IPC (Instrument Panel Cluster) to illuminate the high beam indicator.

Fog Lamp Indicator

When the fog lamps are turned on, the BCM (Body Control Module) sends a fog lamp indicator request to the IPC (Instrument Panel Cluster) to illuminate the fog lamp indicator.

Tire Pressure Monitoring System (TPMS) Warning Indicator

The IPC (Instrument Panel Cluster) receives the TPMS (Tire Pressure Monitoring System) data from the BCM (Body Control Module). The BCM (Body Control Module) receives the tire pressure status message from the TPM (Tire Pressure Monitor) module. If the BCM (Body Control Module) determines the tire pressure has exceeded the low tire pressure limits, a tire pressure status message is sent to the IPC (Instrument Panel Cluster) to illuminate the TPMS (Tire Pressure Monitoring System) warning indicator. If a TPMS (Tire Pressure Monitoring System) fault condition exists, the BCM (Body Control Module) sends the tire pressure status message to the IPC (Instrument Panel Cluster) to flash the TPMS (Tire Pressure Monitoring System) warning indicator.

Air Bag Warning Indicator

The IPC (Instrument Panel Cluster) receives the air bag warning indicator lamp request from the RCM (Restraints Control Module). If a SRS (Supplemental Restraint System) concern is detected, the RCM (Restraints Control Module) sets a DTC (Diagnostic Trouble Code) and sends an air bag indicator lamp request to the IPC (Instrument Panel Cluster) to illuminate the air bag warning indicator.

Safety Belt Warning Indicator

The RCM (Restraints Control Module) monitors the safety belt position through the safety belt buckle switch. The RCM (Restraints Control Module) sends a safety belt indicator request to the IPC (Instrument Panel Cluster) to illuminate the safety belt warning indicator.

Malfunction Indicator Lamp (MIL)

The MIL (Malfunction Indicator Lamp) is controlled by the IPC (Instrument Panel Cluster) using an engine MIL (Malfunction Indicator Lamp) request from the PCM (Powertrain Control Module).

PRNDL Indicator

The IPC (Instrument Panel Cluster) receives the selector lever (PRNDL) status message from the PCM (Powertrain Control Module). The IPC (Instrument Panel Cluster) also uses a park detect switch (part of the selector lever) input to signal the IPC (Instrument Panel Cluster) the shift lever is fully seated in the PARK (P) position. The IPC (Instrument Panel Cluster) compares the park detect switch input with the selector lever (PRNDL) status message sent from the PCM (Powertrain Control Module). The IPC (Instrument Panel Cluster) provides a battery reference voltage to the brake shift interlock. When the selector lever is in PARK (P), the brake shift indicator routes the reference voltage to ground, pulling the circuit low to the IPC (Instrument Panel Cluster). When the selector lever is moved out of PARK (P), the brake shift interlock opens the ground sending the reference voltage high.
The SelectShift display area indicates to the driver which gear is currently selected when the transaxle is in the SelectShift mode. When the transaxle is in SelectShift manual mode, the gear number is displayed in the SelectShift display area.

Terrain Management Indicator

The terrain management warnings inform the driver they have entered or exited one of the various states with respect to the terrain management system. The IPC (Instrument Panel Cluster) receives the terrain display request message from the ATCM (All Terrain Control Module) and displays the terrain management indicator in the 4WD (Four-Wheel Drive) gauge display. The display provides an iconic representation of the selected mode as well as a text-based status message.

Four Wheel Drive (4WD) Gauge

The 4WD (Four-Wheel Drive) gauge displays the level of torque applied to each wheel in a bar graph depicted over the vehicle. The IPC (Instrument Panel Cluster) uses 2 inputs to determine the 4WD (Four-Wheel Drive) gauge display. The first is the wheel torque data message sent from the PCM (Powertrain Control Module). The second is the 4WD (Four-Wheel Drive) lock torque message also sent from the PCM (Powertrain Control Module).
As torque is applied to the wheels, the bars in the display begin to illuminate. The lowest torque displayed is the first bar closest to the wheel. As the amount of torque increases, additional bars are illuminated outward from the wheel.