IPC Diagnosis

INSTRUMENT PANEL CLUSTER (IPC) DIAGNOSIS

The IPC Diagnosis section is divided into the following subsections:
^ Diagnostic Trouble Codes (DTC)
^ IPC Diagnostic Parameters
^ Warning/Status Messages
^ Warning/Status Message Analysis
^ Other IPC Trouble Symptoms
^ Indicator Disclosures
^ For Loss Of Serial Data

Each subsection contains a brief description of the problems along with symptoms, analysis, and possible causes. Extensive use of charts and circuit diagrams has been done to aid the user in trouble-shooting.

DIAGNOSIS OF THIS COMPONENT MAY REQUIRE EXTENSIVE USE OF THE ON-BOARD SELF DIAGNOSTIC SYSTEM. IF YOU ARE UNFAMILIAR WITH THIS SYSTEM, OR AT ANY TIME DURING DIAGNOSIS REQUIRE ADDITIONAL INFORMATION CONCERNING ON-BOARD DIAGNOSTICS.

IPC DIAGNOSTIC PARAMETERS

The Diagnostic Parameters section is divided into three parts:
^ IPC Data Displays
^ IPC Input Displays
^ IPC Output Override Displays

The IPC Data Displays comprise those system input signals containing a Byte of information, generally, but not exclusively, expressed as a value between 0 and 255 counts. The IPC Data Displays may be called up only with the service diagnostics or scan tool.

IPC Input Displays are those inputs which can be represented with a single bit of information. These system signals are represented by a HIGH/LOW designation, HIGH begin equal to a digital '1' and LOW being equal to a digital '0'. The IPC Input displays may only be viewed using the service diagnostics.

IPC Output Override Displays contain information on default option conditions for the vehicle. These default conditions include:
^ Driver Information Center message display suppression
^ Optional Equipment Installations
^ Export Country
^ HVAC Mode Selections

IPC Data Displays:
IPDO1 This displays the AID value for the dimming potentiometer on the headlamp switch. This value can move from 0 to 155 counts under normal operation. Significantly higher values (200 and higher) indicate problems in the circuit.

IPD02 BATTERY VOLTS is displayed in volts between 8.7 and 18.0, on Connector C1 terminals "A1" and "B1" (Controlled Power).

IPD03 The VEHICLE SPEED is shown in miles per hour between 0 and 255.

IPD04 The LOW BRAKE FLUID signal is shown in volts between 0 and 5 volts. 0 volts = low brake fluid or a short to ground in the Low Brake Fluid Switch CKT. 5v = open in Low Brake Fluid Switch CKT. Normal signal voltage is approximately 2.5 volts.

IPD05 The STEERING WHEEL CONTROLS A/D count is displayed from the four steering column lever switch resistors at input Connector C2 terminal "B11," to decode which of eight functions is being requested. There is an invalid deadband position on each side of the eight valid AID count/resistance values. The range of data counts is 0 to 255.

IPD06 Displays the current PASS-Key� II pellet AID value on input Connector Cl terminal "Ab" key high input. Data count range is 0 to 255 counts.

IPD07 The TWILIGHT DELAY POTENTIOMETER displays the current AID value on input Connector Cl terminal "C9." The count range is 0 to 255. This count value represents the 0 to 180 second twilight delay.

IPID08 Displays the current TWILIGHT PHOTOCELL AID count from Connector Cl "C12." This count is used to determine exterior light/dark status. Dark is normally any count above 143 and Light is any value below 123 counts. Both values may be calibrated.

IPD09 to IPD13 Displays the current EEPROM data for Option A to Option E. The data reflects the decimal equivalent of an 8-bit binary code. Range is 0 to 255. No units are associated with this number. See IPC Output Overrides IPSO1 through IPSO5 for recognized values of these options.

IPD14 The IGNITION CYCLE COUNTER value is the number of times that the IPC has been turned "OFF" since a IPC DTC was last detected. After 100 ignition cycles without any malfunction being detected, all IPC DTCs are cleared.

IPD98 The DCP SOFTWARE VERSION is software ID for one of the IPC microprocessors.

IPD99 The CPM SOFTWARE VERSION is software ID for the second IPC microprocessor.

IPC Input Displays:
IP101 Displays the state of the trunk release switch input to the IPC at Connector C1 "D10." Normal state is high. When switch is actuated this level goes low.

IP102 The WASHER FLUID LEVEL SWITCH display is "LOW" when the vehicle is low on washer fluid or input is shorted to ground.

IP103 The ALTERNATOR L-Terminal input will display "LOW" when the ALTERNATOR is not charging. This may be due to the engine not turning or an alternator problem. In addition, if ignition 1 to the IPC is not available, this input will be low.

IP104 The CATALYTIC CONVERTER display is "HIGH" when there is an overtemperature condition.

IP105 The KEY IN IGNITION display is "LOW" when the key is in the ignition and the switch position is ACCY, LOCK or UNLOCK. This input will always be "HIGH" in "RUN" or "CRANK." Use a scan tool to verify switch operation.

IP106 Starter relay diagnostics are not performed, but will show up in service diagnostics. Disregard IP106.

IP107 The HIGH BEAM/FLASH TO PASS display is "HIGH" when the switch is "ON" (switch closed).

IP108 The WIPER 'A' display will be high whenever the wiper switch is NOT in the OFF position.

IP109 The COOLANT LEVEL SWITCH display will be low when the fluid level is acceptable. Due to a heavy filtering algorithm, this input may toggle to high without a 'Check Coolant Level' message on the Driver Information Center.

IP110 The FAST IDLE will display "LOW" when the heated windshield module is ON.

IP112 The INTERIOR LAMPS display is "LOW" when the interior lamps switch is closed on the headlamp switch.

IP113 The HEADLAMP LOW BEAM display is "LOW" when the headlamp switch is closed or when the low beams are "ON" due to automatic feature (e.g. Twilight sentinel, wiper activated headlamps).

IP114 The PARKLAMPS display is "LOW" when the parklamps switch is closed.

IP115 The FRONT FOG LAMP display is "LOW" when the front fog lamp switch is closed.

IP116 The REAR FOG LAMP display is "LOW" when the rear fog lamp switch is closed. Note: export only.

IP117 The TWILIGHT ENABLE display is "HIGH" when the twilight enable switch is NOT in the OFF position. It will be low in the OFF position.

IP118 The FUEL DOOR RELEASE display is "LOW" when the fuel door switch is closed.

IP119 The DRIVER INFO display is "LOW" when the "INFO" switch is closed. This only applies to vehicles equipped with the Analog IPC.

IP120 The TRIP RESET display is "LOW" when the "TRIP RESET" switch is depressed closed. This only applies to vehicles equipped with the Analog IPC.

IP121 The RESET display is low when the "INFO RESET" switch is closed. Note: Pressing this button while in on-board diagnostics, will force the vehicle to exit service diagnostics. Check this input with a scan tool. This only applies to vehicles equipped with the Analog IPC.

IP124 LEFT TURN SWITCH will be high when the left turn switch is ON and the output from the flasher module is on. This input will toggle with the state of the lamps (Lo/Hi).

IP125 RIGHT TURN SWITCH will be high when the right turn switch is ON and the output from the flasher module is on. This input will toggle with the state of the lamps (Lo/Hi).

IPC Override Displays:

NOTICE: An 1P1557 DTC will be set if the flowing procedure is not followed. An 1P1557 is not recoverable and the IPC will have to be replaced. If, while performing the flowing procedure, the "OFF" button is pressed and the IPC displays "IPC CLEAR CODES" Exit on board diagnostics and start over. This will reset the options back to their original settings and prevent 1P1557 from setting.

The current value of a particular override will be displayed on the Trip Odometer location, To enable a feature listed below, add the value of the new feature (shone on the right) to the value shown on the Trip Odometer. Move up by pressing "WARMER" (Digital IPC) or "PASSENGER WARMER" (Analog IPC). Move down by pressing "COOLER" (Digital IPC) or "PASSENGER COOLER" (Analog IPC). To permanently store the changes, press and hold "FRONT DEFROST" and "AUTO/ECON" (Digital IPC) or "FRONT DEFROST" and "A\C" (Analog IPC) until the value on the Trip Odometer flashes once (approximately five seconds).

IPS00 This test will display "none" as no overrides are active at this point

IPS01 Option A
Universal Theft Deterrent Enable 8
Interior Air Purge 1

IPS02 Option B (Export Country)
European Economic Community (EEC) 16
Japan 8
Saudi Arabia 4
Canada 2
Norway/Sweden 1

IPS03 Option C
Premium Unleaded Fuel Only graphic suppression on digital IPC 64
Daytime Running Lamps 32
Cellular Telephone installed 16
BTSI Message Suppression 4
Options Not Set 2
"LOW FUEL LEVEL"message suppression 1

IP504 Option D (HVAC Options)
Afterblow enable 128
De-Ice Installed 64
Timed Recirc enable 16
Dual Zone HVAC Installed 8

IPS05 Option E (Driver Information Center display options)
Coolant Temperature on Driver Information Center 64
Battery Volts on Driver Information Center 32
Engine RPM on Driver Information Center 16
Average Speed on Driver Information Center 8
Vehicle Speed on Driver Information Center 4
Fuel Used on Driver Information Center 2
Instantaneous Fuel Economy on Driver Information Center 1

Note: Digital IPCs have this option set to 90 at assembly plant. Analog IPCs have this option set to 43 at assembly plant.

IPS06 SET TEMPERATURE is used to allow the Set Temperature to be different from the commanded Set Temperature from -5°F to +5°F

IPS07 Incandescent Dimming (INC DIM A) can be moved from OFF to full bright to check lighting.

IPS08 Incandescent Dimming (INC DIM B) can be moved from OFF to full bright to check lighting.

IPS09 Allows Starter Enable output to be overridden for up to 5.0 seconds to verify operation. Vehicle will not start unless IPC PASS-Key II keyword and PCM stored password match.

IPS10 Alternator Disable. This output is not available but has not been removed from the IPC. Changing the value will not affect the IPC in any way.

IPS11 De-Ice Switch allows override of the IPC DeIce switch output. This output will only pulse and will not be constant (i.e. High, Low, High).

DIAGNOSTIC TROUBLE CODE (DTC) CHART

DTC Description
IP 1552 Keep Alive Memory (KAM) Error
IP 1556 IPC EEPROM Odometer Error
IP 1557 EEPROM Calibration Error
IP 1910 Alternator L-Terminal Open Circuit.
IP 1911 Alternator L-Terminal Malfunction
IP 1981 Battery Voltage Too Low
IP 1982 Battery Voltage Too High DTC Description
IP 2016 Loss of PCM Data
IP 2064 Loss of PZM Data
IP2128 Loss of IPC Data
IP 2152 Loss of Heater and A/C Programmer Data
IP 2419 Twilight Sentinel Photo Sensor Malfunction
IP 2510 Steering Wheel Controls HVAC Key Stuck
IP 2511 Steering Wheel Controls Convenience Key Stuck
IP 2515 Steering Wheel Controls illegal Resistance Value
IP 2710 through 2783 PASS-Key II Malfunctions
IP 2710 PASS-Key II Open/Shorted Key Pellet
IP 2711 PASS-Key II Open/Shorted Key Pellet
IP 2750 PASS-Key II Data Communication Failure
IP 2780 PASS-Key II Wrong Resistor Value Before Good
IP 2781 PASS-Key II Wrong Resistor Value After Good
IP 2782 PASS-Key II Pellet Value Not Programmed
IP 2783 PASS-Key II Key Code/Password Corrupted