heated oxygen sensor JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual

INSTALLATION
(1) Install the MHSM,HSM into the bracket.
(2) Position the heated seat module and mounting
bracket onto the power seat track.
(3) Reconnect the power seat wiring harness con-
nectors to the heated seat module.
(4) Install the driver side front bucket seat onto
the power seat track unit (Refer to 23 - BODY/
SEATS/SEAT TRACK ADJUSTER - INSTALLA-
TION).
(5) Reconnect the battery negative cable.
NOTE: If the vehicle is equipped with the optional
Memory System, following installation, it will be
necessary to initialize the Memory Heated Seat
Module (MHSM). In order to function properly, the
MHSM must ªlearnº the sensor values of each of
the power seat motor position transducers in each
of the adjuster hard stop positions. This is done by
performing the ªReset Guard Bandº procedure
using a DRBIIITscan tool and the proper Diagnostic
Procedures manual.
WARNING: THE ªRESET GUARD BANDº PROCE-
DURE WILL CAUSE THE DRIVER SIDE FRONT
SEAT TO AUTOMATICALLY ADJUST TO EACH OF
ITS TRAVEL LIMITS. BE CERTAIN THAT NO ONE IS
SEATED IN THE VEHICLE AND THAT THERE IS
NOTHING IN THE VEHICLE THAT WILL OBSTRUCT
SEAT MOVEMENT. FAILURE TO OBSERVE THIS
WARNING COULD RESULT IN PERSONAL INJURIES
AND/OR VEHICLE DAMAGE.
POWERTRAIN CONTROL
MODULE
DESCRIPTION
DESCRIPTION - PCM
The Powertrain Control Module (PCM) is located
in the engine compartment (Fig. 11). The PCM is
referred to as JTEC.
MODES OF OPERATION
As input signals to the Powertrain Control Module
(PCM) change, the PCM adjusts its response to the
output devices. For example, the PCM must calculate
different injector pulse width and ignition timing for
idle than it does for wide open throttle (WOT).
The PCM will operate in two different modes:
Open Loop and Closed Loop.
During Open Loop modes, the PCM receives input
signals and responds only according to preset PCMprogramming. Input from the oxygen (O2S) sensors
is not monitored during Open Loop modes.
During Closed Loop modes, the PCM will monitor
the oxygen (O2S) sensors input. This input indicates
to the PCM whether or not the calculated injector
pulse width results in the ideal air-fuel ratio. This
ratio is 14.7 parts air-to-1 part fuel. By monitoring
the exhaust oxygen content through the O2S sensor,
the PCM can fine tune the injector pulse width. This
is done to achieve optimum fuel economy combined
with low emission engine performance.
The fuel injection system has the following modes
of operation:
²Ignition switch ON
²Engine start-up (crank)
²Engine warm-up
²Idle
²Cruise
²Acceleration
²Deceleration
²Wide open throttle (WOT)
²Ignition switch OFF
The ignition switch On, engine start-up (crank),
engine warm-up, acceleration, deceleration and wide
open throttle modes are Open Loop modes. The idle
and cruise modes, (with the engine at operating tem-
perature) are Closed Loop modes.
IGNITION SWITCH (KEY-ON) MODE
This is an Open Loop mode. When the fuel system
is activated by the ignition switch, the following
actions occur:
Fig. 11 PCM Location
1 - PCM
2 - COOLANT TANK
8E - 12 ELECTRONIC CONTROL MODULESWJ
MEMORY HEATED SEAT/MIRROR MODULE (Continued)

8W-02 COMPONENT INDEX
Component Page
A/C Compressor Clutch................. 8W-42
A/C Pressure Transducer................ 8W-42
Accelerator Pedal Position Sensor......... 8W-30
Accessory Delay Relay.................. 8W-64
Adjustable Pedals..................... 8W-30
Airbags............................. 8W-43
Ambient Temperature Sensor............ 8W-45
Antennas............................ 8W-47
Ash Receiver Lamp.................... 8W-44
Auto Shut Down Relay................. 8W-30
Automatic Day/Night Mirror............. 8W-49
Automatic Headlamp Light Sensor/VTSS
LED.............................. 8W-39
Automatic Zone Control Module.......... 8W-42
Back-Up Lamp Relay................... 8W-51
Battery Temperature Sensor............. 8W-30
Battery............................. 8W-20
Blend Door Motor/Actuator.............. 8W-42
Blower Motor......................... 8W-42
Body Control Module................... 8W-45
Boost Pressure Sensor.................. 8W-30
Brake Lamp Switch.................... 8W-33
Camshaft Position Sensor............... 8W-30
Capacitors........................... 8W-30
Cargo Lamp.......................... 8W-44
Center High Mounted Stop Lamp......... 8W-51
Cigar Lighter......................... 8W-41
Circuit Breakers...................... 8W-12
Clockspring.................. 8W-33, 41, 43, 47
Coil On Plugs......................... 8W-30
Coil Rail............................. 8W-30
Combination Flasher................... 8W-52
Compact Disc Changer.................. 8W-47
Controller Antilock Brake............... 8W-35
Coolant Level Sensor................... 8W-45
Courtesy Lamps....................... 8W-44
Crankcase Heater..................... 8W-30
Crankshaft Position Sensor.............. 8W-30
Cylinder Lock Switches................. 8W-61
Data Link Connector................... 8W-18
Diagnostic Junction Port................ 8W-18
EGR Solenoid......................... 8W-30
Electric Brake........................ 8W-54
Electronic Speed Control Servo........... 8W-33
Engine Control Module................. 8W-30
Engine Coolant Temperature Sensor...... 8W-30
Engine Oil Pressure Sensor.............. 8W-30
Engine Starter Motor................... 8W-21
EVAP/Purge Solenoid................... 8W-30
Fog Lamps........................ 8W-50, 51
Fuel Injectors......................... 8W-30
Fuel Pressure Sensor................... 8W-30Component Page
Fuel Pressure Solenoid................. 8W-30
Fuel Pump........................... 8W-30
Fuel Tank Module..................... 8W-30
Fuses............................ 8W-10, 12
Fusible Link....................... 8W-10, 20
Grounds............................. 8W-15
Generator......................... 8W-20, 30
Glove Box Lamp...................... 8W-44
Glow Plugs........................... 8W-30
Headlamp Leveling Motor............... 8W-50
Heated Seats......................... 8W-63
High Beam Headlamps................. 8W-50
Hood Ajar Switch...................... 8W-39
Horns............................... 8W-41
Hydraulic Cooling Module............ 8W-30, 42
Idle Air Control Motor.................. 8W-30
Ignition Switch....................... 8W-10
Impact Sensors....................... 8W-43
Input Speed Sensor.................... 8W-31
Instrument Cluster.................... 8W-40
Intake Air Temperature Sensor........... 8W-30
Intake Port Swirl Actuator.............. 8W-30
Intrusion Transceiver Module............ 8W-49
Junction Block........................ 8W-12
Knock Sensor......................... 8W-30
Lamp Assemblies................... 8W-51, 52
Leak Detection Pump.................. 8W-30
License Lamps........................ 8W-51
Liftgate............................. 8W-61
Line Pressure Sensor................... 8W-31
Low Beam Headlamps.................. 8W-50
Low Beam Relay...................... 8W-50
Low Beam/Daytime Running Lamp Relay . . . 8W-50
Lumbar Motor........................ 8W-63
Lumbar Switch....................... 8W-63
Manifold Absolute Pressure Sensor........ 8W-30
Manual Temperature Control............. 8W-42
Mass Air Flow Sensor.................. 8W-30
Memory Set Switch................. 8W-62, 63
Mode Door Motor/Actuator............... 8W-42
Multi-Function Switch............... 8W-50, 53
Output Speed Sensor................... 8W-31
Overhead Map/Courtesy Lamp........... 8W-44
Oxygen Sensors....................... 8W-30
Park Brake Switch..................... 8W-40
Park Lamp........................... 8W-50
Park/Neutral Position Switch............ 8W-31
Park/Turn Signal Lamps................ 8W-50
Power Amplifier....................... 8W-47
Power Connector...................... 8W-41
Power Distribution Center............... 8W-10
Power Mirrors........................ 8W-62
WJ8W-02 COMPONENT INDEX 8W - 02 - 1

8W-15 GROUND DISTRIBUTION
Component Page
A/C Compressor Clutch.................. 8W-15-4
Adjustable Pedals Module............. 8W-15-17, 21
Airbag Control Module.................. 8W-15-16
Ash Receiver Lamp.................... 8W-15-14
Automatic Day/Night Mirror.............. 8W-15-19
Automatic Zone Control Module........... 8W-15-15
Battery............................ 8W-15-2, 3
Blower Motor Controller................. 8W-15-15
Body Control Module.............. 8W-15-12, 13, 15
Brake Lamp Switch................. 8W-15-17, 22
Center High Mounted Stop Lamp.......... 8W-15-20
Cigar Lighter........................ 8W-15-14
Cigar Lighter Relay.................... 8W-15-12
Controller Antilock Brake................ 8W-15-12
Coolant Level Sensor............... 8W-15-9, 10, 11
Crankcase Heater...................... 8W-15-4
Data Link Connector.................. 8W-15-2, 3
Driver Cylinder Lock Switch.............. 8W-15-16
Driver Door Lock Motor/Ajar Switch........ 8W-15-16
Driver Door Module.................... 8W-15-16
Driver Heated Seat Switch............... 8W-15-14
Driver Lumbar Switch............... 8W-15-18, 21
Driver Power Seat Switch............. 8W-15-18, 21
Driver Rear Power Window Switch....... 8W-15-18, 21
Electric Brake........................ 8W-15-17
Electronic Speed Control Servo.......... 8W-15-9, 10
Engine Control Module.................. 8W-15-3
Front Power Outlet.................... 8W-15-14
Front Washer Pump................... 8W-15-6, 7
Front Wiper Motor.................... 8W-15-6, 7
Fuel Pump Module.................... 8W-15-19
G100............................. 8W-15-2, 3
G101............................. 8W-15-2, 3
G102............................... 8W-15-2
G103............................. 8W-15-2, 3
G104............................... 8W-15-4
G105............................... 8W-15-4
G106............................. 8W-15-6, 7
G107.............................. 8W-15-12
G108.......................... 8W-15-9, 10, 11
G200......................... 8W-15-13, 14, 15
G201.............................. 8W-15-16
G300......................... 8W-15-16, 17, 18
G301......................... 8W-15-19, 21, 22
Headlamp Leveling Switch............... 8W-15-15
Hood Ajar Switch..................... 8W-15-6, 7
Horn No. 1...................... 8W-15-9, 10, 11
Horn No. 2...................... 8W-15-9, 10, 11
Hydraulic Cooling Module........... 8W-15-9, 10, 11
Ignition Switch....................... 8W-15-15
Instrument Cluster.................. 8W-15-13, 14
Intake Port Swirl Actuator................ 8W-15-3
Intrusion Transceiver Module.......... 8W-15-21, 22
Junction Block.................. 8W-15-12, 13, 15
Left Fog Lamp...................... 8W-15-6, 7
Left Front Park Lamp................... 8W-15-5
Left Front Park/Turn Signal Lamp.......... 8W-15-5
Left Front Turn Signal Lamp.............. 8W-15-5
Left Headlamp Leveling Motor............. 8W-15-5
Left High Beam Headlamp................ 8W-15-5
Component Page
Left Liftgate Ajar Switch................ 8W-15-20
Left Low Beam Headlamp................ 8W-15-5
Left Multi-Function Switch............... 8W-15-15
Left Rear Door Lock Motor/Ajar Switch.... 8W-15-21, 22
Left Rear Lamp Assembly............... 8W-15-19
Left Side Repeater Lamp............... 8W-15-6, 7
License Lamp No. 1.................... 8W-15-20
License Lamp No. 2.................... 8W-15-20
Liftgate Flip-Up Ajar Switch.............. 8W-15-20
Liftgate Flip-Up Release Solenoid.......... 8W-15-20
Line Pressure Sensor.................... 8W-15-2
Low Beam/Daytime Running Lamp Relay.... 8W-15-12
Manual Temperature Control........... 8W-15-13, 15
Oxygen Sensor 1/2 Downstream............ 8W-15-4
Oxygen Sensor 2/2 Downstream............ 8W-15-4
Park Lamp Relay..................... 8W-15-12
Passenger Door Lock Motor/Ajar Switch...... 8W-15-16
Passenger Door Module................. 8W-15-16
Passenger Heated Seat Switch............ 8W-15-14
Passenger Lumbar Switch............. 8W-15-17, 22
Passenger Power Seat Switch.......... 8W-15-17, 22
Passenger Rear Power Window Switch.... 8W-15-16, 22
Power Amplifier.................... 8W-15-17, 18
Power Connector...................... 8W-15-15
Powertrain Control Module............... 8W-15-2
Radio........................... 8W-15-17, 18
Rain Sensor....................... 8W-15-21, 22
Rear Power Outlet.................. 8W-15-17, 18
Rear Washer Pump................... 8W-15-6, 7
Rear Window Defogger.................. 8W-15-20
Rear Wiper Motor..................... 8W-15-20
Remote Keyless Module................. 8W-15-16
Right Fog Lamp.................. 8W-15-9, 10, 11
Right Front Park Lamp.................. 8W-15-8
Right Front Park/Turn Signal Lamp......... 8W-15-8
Right Front Turn Signal Lamp............. 8W-15-8
Right Headlamp Leveling Motor............ 8W-15-8
Right High Beam Headlamp............... 8W-15-8
Right Low Beam Headlamp............... 8W-15-8
Right Rear Door Lock Motor/Ajar Switch . . 8W-15-16, 18
Right Rear Lamp Assembly............ 8W-15-17, 18
Right Side Repeater Lamp........... 8W-15-9, 10, 11
Seat Module...................... 8W-15-18, 21
Sentry Key Immobilizer Module........... 8W-15-13
Shifter Assembly................... 8W-15-14, 15
Siren............................. 8W-15-6, 7
Sunroof Control Module................. 8W-15-19
Sunroof Motor........................ 8W-15-19
Sunroof Switch....................... 8W-15-19
Temperature Valve Actuator.............. 8W-15-13
Trailer Tow Brake Lamp Relay............ 8W-15-19
Trailer Tow Connector.................. 8W-15-19
Trailer Tow Left Turn Relay.............. 8W-15-19
Trailer Tow Right Turn Relay............. 8W-15-19
Transmission Control Module.............. 8W-15-2
Transmission Control Relay............ 8W-15-9, 10
Underhood Lamp..................... 8W-15-6, 7
Vehicle Information Center............ 8W-15-21, 22
Viscous/Cabin Heater................... 8W-15-4
Washer Fluid Level Switch.............. 8W-15-6, 7
WJ8W-15 GROUND DISTRIBUTION 8W - 15 - 1

Component Page
LIFTGATE FLIP-UP PUSH
BUTTON SWITCH................ 8W-80-97
LIFTGATE FLIP-UP RELEASE
SOLENOID...................... 8W-80-97
LIFTGATE POWER LOCK MOTOR..... 8W-80-97
LINE PRESSURE SENSOR (4.7L)...... 8W-80-98
MANIFOLD ABSOLUTE PRESSURE
SENSOR (4.0L)................... 8W-80-98
MANIFOLD ABSOLUTE PRESSURE
SENSOR (4.7L)................... 8W-80-98
MANUAL TEMPERATURE
CONTROL C1 (MTC).............. 8W-80-98
MANUAL TEMPERATURE
CONTROL C2 (MTC).............. 8W-80-99
MASS AIR FLOW SENSOR (DIESEL) . . . 8W-80-99
MODE DOOR MOTOR/ACTUATOR
(AZC).......................... 8W-80-99
NEEDLE MOVEMENT SENSOR
(DIESEL)....................... 8W-80-99
OUTPUT SPEED SENSOR (4.0L)...... 8W-80-99
OUTPUT SPEED SENSOR (4.7L)..... 8W-80-100
OVERHEAD MAP/COURTESY LAMP . . 8W-80-100
OXYGEN SENSOR 1/1 UPSTREAM.... 8W-80-100
OXYGEN SENSOR 1/2 DOWNSTREAM . 8W-80-100
OXYGEN SENSOR 2/1 UPSTREAM.... 8W-80-100
OXYGEN SENSOR 2/2
DOWNSTREAM................. 8W-80-101
PARK/NEUTRAL POSITION SWITCH
(4.0L).......................... 8W-80-101
PARK/NEUTRAL POSITION SWITCH
(DIESEL)...................... 8W-80-101
PASSENGER AIRBAG.............. 8W-80-101
PASSENGER BLEND DOOR
MOTOR/ACTUATOR (LHD) (AZC) . . . 8W-80-101
PASSENGER BLEND DOOR
MOTOR/ACTUATOR (RHD) (AZC) . . . 8W-80-102
PASSENGER CURTAIN AIRBAG...... 8W-80-102
PASSENGER DOOR LOCK MOTOR/AJAR
SWITCH....................... 8W-80-102
PASSENGER DOOR MODULE C1..... 8W-80-102
PASSENGER DOOR MODULE C2..... 8W-80-103
PASSENGER FRONT DOOR
COURTESY LAMP............... 8W-80-103
PASSENGER FRONT POWER
WINDOW MOTOR............... 8W-80-103
PASSENGER HEATED SEAT BACK
(PREMIUM I/III)................. 8W-80-103
PASSENGER HEATED SEAT CUSHION
(PREMIUM I/III)................. 8W-80-104
PASSENGER HEATED SEAT SWITCH . 8W-80-104
PASSENGER LUMBAR MOTOR
(MIDLINE/PREMIUM)............ 8W-80-104
PASSENGER LUMBAR SWITCH
(MIDLINE/PREMIUM)............ 8W-80-104
PASSENGER POWER MIRROR....... 8W-80-105Component Page
PASSENGER POWER SEAT FRONT
RISER MOTOR.................. 8W-80-105
PASSENGER POWER SEAT
HORIZONTAL MOTOR........... 8W-80-105
PASSENGER POWER SEAT REAR
RISER MOTOR.................. 8W-80-105
PASSENGER POWER SEAT RECLINER
MOTOR (MIDLINE/PREMIUM)..... 8W-80-106
PASSENGER POWER SEAT SWITCH
(MIDLINE/PREMIUM)............ 8W-80-106
PASSENGER REAR POWER
WINDOW MOTOR............... 8W-80-106
PASSENGER REAR POWER
WINDOW SWITCH............... 8W-80-106
PASSENGER SEAT BELT SWITCH.... 8W-80-106
PASSENGER SIDE IMPACT
SENSOR....................... 8W-80-107
POWER AMPLIFIER C1
(PREMIUM RADIO).............. 8W-80-107
POWER AMPLIFIER C2
(PREMIUM RADIO).............. 8W-80-107
POWER CONNECTOR.............. 8W-80-108
POWERTRAIN CONTROL
MODULE C1 (GAS).............. 8W-80-108
POWERTRAIN CONTROL
MODULE C2 (GAS).............. 8W-80-109
POWERTRAIN CONTROL
MODULE C3 (GAS).............. 8W-80-110
RADIATOR FAN MOTOR............ 8W-80-110
RADIATOR FAN RELAY............. 8W-80-111
RADIO C1........................ 8W-80-111
RADIO C2........................ 8W-80-111
RAIN SENSOR (AUTOWIPE)......... 8W-80-112
REAR POWER OUTLET............. 8W-80-112
REAR WASHER PUMP.............. 8W-80-112
REAR WIPER MOTOR.............. 8W-80-112
RECIRCULATION DOOR
MOTOR/ACTUATOR (AZC)......... 8W-80-112
RED BRAKE WARNING INDICATOR
SWITCH....................... 8W-80-113
REMOTE KEYLESS MODULE
(JAPAN)....................... 8W-80-113
RIGHT COURTESY LAMP........... 8W-80-113
RIGHT DOOR HANDLE
COURTESY LAMP............... 8W-80-113
RIGHT FOG LAMP................. 8W-80-113
RIGHT FRONT DOOR SPEAKER..... 8W-80-114
RIGHT FRONT IMPACT SENSOR..... 8W-80-114
RIGHT FRONT PARK LAMP......... 8W-80-114
RIGHT FRONT PARK/TURN SIGNAL LAMP
(EXCEPT BUILT-UP-EXPORT)...... 8W-80-114
RIGHT FRONT SIDE MARKER LAMP
(EXCEPT BUILT-UP-EXPORT)...... 8W-80-115
RIGHT FRONT TURN SIGNAL LAMP
(BUILT-UP-EXPORT)............. 8W-80-115
8W - 80 - 4 8W-80 CONNECTOR PIN-OUTWJ

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Output Speed Sensor (4.0L) GY Left Side of Transmission 12
Output Speed Sensor (4.7L) BK Left Side of Transmission 16
Overhead Map/Courtesy Lamp WT At Overhead Console N/S
Oxygen Sensor 1/1 Upstream
(4.0L)GY Left Side of Engine at Exhaust 9, 12
Oxygen Sensor 1/1 Upstream
(4.7L)GY Left Side of Engine at Exhaust 17
Oxygen Sensor 1/2
Downstream (4.0L)BK Rear of Transmission 9, 12
Oxygen Sensor 1/2
Downstream (4.7L)BK Rear of Transmission 17
Oxygen Sensor 2/1 Upstream Rear of Transmission N/S
Oxygen Sensor 2/2
DownstreamRear of Transmission N/S
Park Brake Switch Center Console Area, Near Airbag
Control Module20, 21, 22
Park/Neutral Position Switch
(4.0L)BK Left Side of Transmission 12
Park/Neutral Position Switch
(Diesel)BK Left Side of Transmission N/S
Passenger Airbag YL Passenger Side of Instrument Panel 19, 20
Passenger Blend Door
Motor/Actuator (AZC)BK Passenger Side of Instrument Panel N/S
Passenger Door Lock
Motor/Ajar SwitchBK In Passenger Door 26, 27
Passenger Door Module - C1 WT In Passenger Door 26, 27
Passenger Door Module - C2 BK In Passenger Door N/S
Passenger Front Door
Courtesy LampBK In Passenger Door N/S
Passenger Front Power
Window MotorBK In Passenger Door 26, 27
Passenger Heated Seat Back
(Premium I/III)GN At Passenger Seat N/S
Passenger Heated Seat
Cushion (Premium I/III)BK At Passenger Seat N/S
Passenger Heated Seat Switch BK Center of Instrument Panel 19, 20, 21
Passenger Lumbar Motor
(Midline/Premium)BK At Passenger Seat N/S
Passenger Lumbar Switch
(Midline/Premium)WT At Passenger Seat N/S
Passenger Power Mirror BK In Passenger Door N/S
Passenger Power Seat Front
Riser MotorRD At Passenger Seat N/S
Passenger Power Seat
Horizontal MotorRD At Passenger Seat N/S
8W - 91 - 8 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONWJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P1110 Decrease Engine Performance Due
To High Intake Air TemperatureIntake manifold air temperature is above the engine
protection limit. Engine power will be derated.
P1180 Decreased Engine Performance Due
To High Injection Pump Fuel TempFuel temperature is above the engine protection limit.
Engine power will be derated.
P1192 Intake Air Temp Sensor Voltage Low
P1193 Intake Air Temp Sensor Voltage High
P1194 O2 Heater Performance
P1195 (M) 1/1 O2 Sensor Slow During Catalyst
MonitorA slow switching oxygen sensor has been detected in
bank 1/1 during catalyst monitor test. (Also see SCI DTC
$66) (was P0133)
P1196 (M) 2/1 O2 Sensor Slow During Catalyst
MonitorA slow switching oxygen sensor has been detected in
bank 2/1 during catalyst monitor test. (Also see SCI DTC
$7A) (was P0153)
P1197 1/2 O2 Sensor Slow During Catalyst
MonitorA slow switching oxygen sensor has been detected in
bank 1/2 during catalyst monitor test. (Also see SCI DTC
$68) (was P0139)
P1198 Radiator Temperature Sensor Volts
Too HighRadiator coolant temperature sensor input above the
maximum acceptable voltage.
P1199 Radiator Temperature Sensor Volts
Too LowRadiator coolant temperature sensor input below the
minimum acceptable voltage.
P1280 Fuel System Relay Circuit
P1281 Engine is Cold Too Long Engine coolant temperature remains below normal
operating temperatures during vehicle travel (Thermostat).
P1282 Fuel Pump/System Relay Control
CircuitAn open or shorted condition detected in the fuel pump
relay control circuit.
P1283 Idle Select Signal Invalid ECM or fuel injection pump module internal fault condition
detected.
P1284 (M) Fuel Injection Pump Battery Voltage
Out-Of-RangeFuel injection pump module internal fault condition
detected. Engine power will be derated.
P1285 (M) Fuel Injection Pump Controller
Always OnFuel injection pump module relay circuit failure detected.
Engine power will be derated.
P1286 Accelerator Position Sensor (APPS)
Supply Voltage Too HighHigh voltage detected at APPS.
P1287 Fuel Injection Pump Controller
Supply Voltage LowECM or fuel injection pump module internal fault condition
detected. Engine power will be derated.
P1288 Intake Manifold Short Runner
Solenoid CircuitAn open or shorted condition detected in the short runner
tuning valve circuit.
P1289 Manifold Tune Valve Solenoid Circuit An open or shorted condition detected in the manifold
tuning valve solenoid control circuit.
P1290 High Pressure Solenoid Relay Ckt. CNG Fuel System Pressure Too High±Compressed
natural gas system pressure above normal operating
range.
P1291 No Temp Rise Seen From Intake
HeatersEnergizing Heated Air Intake does not change intake air
temperature sensor an acceptable amount.
WJEMISSIONS CONTROL 25 - 11
EMISSIONS CONTROL (Continued)