TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the CAB harness connector.
Using a 12-volt test light connected to ground, check both Fused B(+) circuits at the
CAB harness connector.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Go To 5
No!Repair the Fused B(+) circuit for high resistance.
Perform ABS VERIFICATION TEST - VER 1.
5 Turn the ignition off.
Disconnect the CAB harness connector.
Using a 12-volt test light connected to 12-volts, check the CAB harness connector
Ground circuits.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Does the test light illuminate brightly?All
Ye s!Replace the Controller Antilock Brake in accordance with the
Service Information.
Perform ABS VERIFICATION TEST - VER 1.
No!Repair the Ground circuit for high resistance.
Perform ABS VERIFICATION TEST - VER 1.
6 Turn the ignition off.
Visually inspect the related wiring harness.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out, or corroded terminals.
Were any problems found?All
Ye s!Repair as necessary.
Perform ABS VERIFICATION TEST - VER 1.
No!Test Complete.
78
BRAKES (CAB)
SYSTEM UNDERVOLTAGE ÐContinued
Verification Tests
ABS VERIFICATION TEST - VER 1 APPLICABILITY
1. Turn the ignition off.
2. Connect all previously disconnected components and connectors.
3. Ensure all accessories are turned off and the battery is fully charged.
4. Ensure that the Ignition is on, and with the DRBIII, erase all Diagnostic Trouble Codes from
ALL modules. Start the engine and allow it to run for 2 minutes and fully operate the system
that was malfunctioning.
5. Turn the ignition off and wait 5 seconds. Turn the ignition on and using the DRBIII, read
DTC's from ALL modules.
6. If any Diagnostic Trouble Codes are present, return to Symptom list and troubleshoot new
or recurring symptom.
7. NOTE: If the CAB/HCU was replaced, ensure the CAB has been initialized
8. NOTE: If the SKREEM or ECM was replaced, refer to the service information for
proper programming procedures.
9. NOTE: For Sensor Circuit/Signal and Pump Motor faults, the CAB must sense all 4
wheels at 12 km/h (8 mph) before it will extinguish the ABS Indicator.
10. If there are no DTC's present after turning ignition on, road test the vehicle for at least 5
minutes. Perform several antilock braking stops.
11. CAUTION: Ensure braking capability is available before road testing.
12. Again, with the DRBIIItread DTC's. If any DTC's are present, return to Symptom list.
13. If there are no Diagnostic Trouble Codes (DTC's) present, and the customer's concern can
no longer be duplicated, the repair is complete.
Are any DTC's present or is the original concern still present?All
Ye s!Repair is not complete, refer to appropriate symptom.
No!Repair is complete.
79
VERIFICATION TESTS
BODY VERIFICATION TEST - VER 1 APPLICABILITY
1. Disconnect all jumper wires and reconnect all previously disconnected components and
connectors.
2. Ensure that all accessories are turned off and the battery is fully charged.
3. NOTE: Refer to the service information for proper programming procedures if the
ABM; ACM; ATC; CTM; ECM; IC; SKREEM; SLA; or SSM was replaced.
4. If the SKREEM was replaced, program all RKE transmitters used with this vehicle.
5. NOTE: Perform the next 8 steps of this procedure if either diagnosing the
Automatic Temperature Control (ATC) system or if repairs were made to the ATC
system. All of the following criteria must be met in order to successfully run the ATC
Function Test.
6. With DRBIIIt, record and erase ATC DTCs.
7. Place the shift lever in Park.
8. Start the engine. Allow the engine to reach normal operating temperature.
9. Set the blower to high speed.
10. Press the Air Conditioning switch On.
11. With the DRBIIIt, verify that the ambient temperature is above 59ÉF (15ÉC), the refrigerant
pressure is between 29 and 348 PSI (2 and 24 bar), the evaporator temperature is above 36.5ÉF
(2.5ÉC), and the coolant temperature is above 158ÉF (70ÉC).
12. With the DRBIIItin ATC, select System Tests and select ATC Function Test. When the ATC
Function Test is complete, proceed to the next step of this procedure.
13. With the DRBIIIt, read active ATC DTCs. If any DTC is active or if the original condition
is still present, proceed to the conclusion question and answer Yes.
14. With the DRBIIIt, record and erase all DTCs from ALL modules. Start and run the engine
for 2 minutes. Operate all functions of the system that caused the original concern.
15. Turn the ignition off and wait 5 seconds. Turn the ignition on and using the DRBIIIt, read
DTCs from ALL modules.
Are any DTC's present or is the original condition still present?All
Ye s!Repair is not complete, refer to the appropriate symptom.
No!Repair is complete.
80
VERIFICATION TESTS
Verification Tests ÐContinued
9.0 CONNECTOR PINOUTS
BRAKE FLUID LEVEL SWITCHCAV CIRCUIT FUNCTION
1 20BR/YL BRAKE FLUID LEVEL INDICATOR SIGNAL
2 16BR GROUND
BRAKE LAMP SWITCH C1 (EXCEPT ESP)CAV CIRCUIT FUNCTION
1 20WT BRAKE SWITCH OUTPUT
2 16RD/BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
3 20BK/BL/RD BRAKE LAMP SWITCH
4- -
BRAKE LAMP SWITCH C2 (EXCEPT ESP) - BLACKCAV CIRCUIT FUNCTION
1 16BK/BL/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
2 16BK/RD BRAKE LAMP SWITCH OUTPUT
3- -
C
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83
CONNECTOR PINOUTS
INSTRUMENT CLUSTER C2 - WHITECAV CIRCUIT FUNCTION
1- -
2- -
3 20RD/YL FUSED B(+)
4 20BR/WT BRAKE WEAR SENSOR SIGNAL
5- -
6 18BR GROUND
7 20GY/DG/RD LAMP DRIVER
8 20BL/WT FUSED HIGH BEAM SWITCH OUTPUT
9 20BL/RD/WT VEHICLE SPEED SENSOR OUTPUT
10 20BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
11 20BL/BK KEY-IN IGNITION SWITCH SIGNAL
12 - -
13 20BK/WT LEFT TURN SIGNAL
14 20BR/YL BRAKE FLUID LEVEL INDICATOR SIGNAL
15 20BL GENERATOR FIELD DRIVER
16 20YL AIRBAG WARNING INDICATOR DRIVER
17 - -
18 20BL/VT D(+) RELAY NO. 1 CONTROL
18 20BL/VT D(+) RELAY NO. 1 CONTROL
STEERING ANGLE SENSORCAV CIRCUIT FUNCTION
1 20DG/WT CAN C BUS (-)
2- -
3 20DG CAN C BUS (+)
4- -
5 20BK/RD FUSED OPTIONAL EQUIPMENT RELAY OUTPUT
6 20BR GROUND
TCS SWITCH (ASR) - BLACKCAV CIRCUIT FUNCTION
1 16GY/DG/RD LAMP DRIVER
2- -
3 18BK/BL TCS SWITCH (ASR) SENSE
4- -
5- -
6- -
7 16BK/BL/DG FUSED IGNITION SWITCH OUTPUT
8- -
9- -
10 16BR GROUND
WHEEL SPEED SENSOR-LEFT FRONTCAV CIRCUIT FUNCTION
1 18BK LEFT FRONT WHEEL SPEED SENSOR (+)
2 18BR LEFT FRONT WHEEL SPEED SENSOR (-)
C
O
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85
CONNECTOR PINOUTS
TABLE OF CONTENTS - Continued
P1480-GLOW PLUG INDICATOR ERROR...................................79
P1482-GLOW PLUG MODULE - COMMUNICATION ERROR....................80
P2537-GLOW PLUG CONTROL CIRCUIT PREGLOW FAULT...................80
P2537-GLOW PLUG CONTROL CIRCUIT PREGLOW SHORT TO GROUND.......80
P2537-GLOW PLUG CONTROL CIRCUIT PREGLOW SHORT TO VOLTAGE......80
P1482-GLOW PLUG MODULE - EXCESS CURRENT..........................82
P2133-GLOW PLUG #1 CIRCUIT EXCESSIVE CURRENT......................82
P2133-GLOW PLUG #1 CIRCUIT OPEN CIRCUIT............................82
P2133-GLOW PLUG #1 CIRCUIT SHORT TO GROUND.......................82
P2133-GLOW PLUG #1 CIRCUIT SHORT TO VOLTAGE.......................82
P2134-GLOW PLUG #2 CIRCUIT EXCESSIVE CURRENT......................82
P2134-GLOW PLUG #2 CIRCUIT OPEN CIRCUIT............................82
P2134-GLOW PLUG #2 CIRCUIT SHORT TO GROUND.......................82
P2134-GLOW PLUG #2 CIRCUIT SHORT TO VOLTAGE.......................82
P2135-GLOW PLUG #3 CIRCUIT EXCESSIVE CURRENT......................82
P2135-GLOW PLUG #3 CIRCUIT OPEN CIRCUIT............................82
P2135-GLOW PLUG #3 CIRCUIT SHORT TO GROUND.......................82
P2135-GLOW PLUG #3 CIRCUIT SHORT TO VOLTAGE.......................82
P2136-GLOW PLUG #4 CIRCUIT EXCESSIVE CURRENT......................82
P2136-GLOW PLUG #4 CIRCUIT OPEN CIRCUIT............................82
P2136-GLOW PLUG #4 CIRCUIT SHORT TO GROUND.......................82
P2136-GLOW PLUG #4 CIRCUIT SHORT TO VOLTAGE.......................82
P2137-GLOW PLUG #5 CIRCUIT EXCESSIVE CURRENT......................82
P2137-GLOW PLUG #5 CIRCUIT OPEN CIRCUIT............................82
P2137-GLOW PLUG #5 CIRCUIT SHORT TO GROUND.......................82
P2137-GLOW PLUG #5 CIRCUIT SHORT TO VOLTAGE.......................82
P1482-GLOW PLUG MODULE - INCORRECT TIMER.........................85
P1482-GLOW PLUG MODULE - INTERNAL FAULT...........................85
P2538-GLOW PLUG MODULE COMMUNICATION ERROR.....................85
P2538-GLOW PLUG MODULE EXCESSIVE CURRENT ERROR.................85
P2538-GLOW PLUG MODULE TIMER ERROR...............................85
P1610-ENGINE CONTROL RELAY PLAUSIBILITY............................87
P1610-ENGINE CONTROL RELAY SHUTS OFF TOO EARLY...................89
P1610-ENGINE CONTROL RELAY SHUTS OFF TOO LATE....................91
P1611-SENSOR SUPPLY 1 VOLTAGE IS TOO HIGH..........................94
P1611-SENSOR SUPPLY 1 VOLTAGE IS TOO LOW..........................96
P1612-IGNITION VOLTAGE - VOLTAGE ERROR.............................99
P1615-ECM VOLTAGE SUPPLY IS TOO HIGH..............................100
P1615-ECM VOLTAGE SUPPLY IS TOO LOW...............................100
P1630-IMMOBILIZER...................................................102
P1630-IMMOBILIZER...................................................102
P1630-IMMOBILIZER...................................................102
P1630-IMMOBILIZER...................................................102
P2201-IMMOBILIZER CAN MESSAGE ERROR..............................102
P2243-NO MESSAGE RECEIVED FROM SKREEM..........................102
P1681-ACM CIRCUIT FAULT.............................................104
P1681-ACM CIRCUIT SHORT TO VOLTAGE................................104
P2009-WATER IN FUEL SENSOR - WATER IN FUEL.........................106
P2009-WATER IN FUEL SENSOR SIGNAL ERROR..........................106
P2010-MASS AIR FLOW SENSOR NEGATIVE DEVIATION....................110
P2010-MASS AIR FLOW SENSOR POSITIVE DEVIATION.....................110
P2068-MASS AIR FLOW SENSOR PLAUSIBILITY SIGNAL RATIO TOO LARGE . . .110
P2068-MASS AIR FLOW SENSOR PLAUSIBILITY SIGNAL RATIO TOO SMALL . . .110
v
TABLE OF CONTENTS - Continued
KICK DOWN SWITCH - BLACK...........................................271
MASS AIR FLOW SENSOR - BLACK......................................271
OXYGEN SENSOR (OBD)...............................................271
FUSED IGNITION SWITCH RUN-START RELAY (RELAY BLOCK)..............273
SPEED CONTROL SWITCH.............................................273
WATER IN FUEL SENSOR - BLACK.......................................273
10.0 SCHEMATIC DIAGRAMS................................................275
10.1ENGINE CONTROL MODULE.......................................275
10.2ENGINE CONTROL MODULE.......................................276
11.0 CHARTS AND GRAPHS................................................277
xi
3.2.2 ECM OPERATING MODES
As input signals to the ECM change, the ECM
adjusts its response to the output devices. For
example, the ECM must calculate a different fuel
quantity and fuel timing for engine idle condition
than it would for a wide open throttle condition.
There are several different modes of operation that
determine how the ECM responds to the various
input signals.
Ignition Switch On (Engine Off)
When the ignition is turned on the ECM activates
the glow plug relay for a time period that is deter-
mined by engine coolant temperature, intake air
temperature and battery voltage.
Engine Start-Up Mode
The ECM uses the intake air temperature sensor,
engine temperature sensor and the crankshaft po-
sition sensor (engine speed) inputs to determine
fuel injection quantity.
Normal Driving Modes
Engine idle, warm-up, acceleration, deceleration
and wide open throttle modes are controlled based
on all of the sensor inputs to the ECM. The ECM
uses these sensor inputs to adjust fuel quantity and
fuel injector timing. EGR valve control is performed
using feedback from the oxygen sensor. An oxygen
sensor is located in the exhaust manifold to sample
oxygen content exiting the engine cylinders. The
ECM uses the O2 sensor, along with other sensor
inputs, to govern the amount of exhaust gas recir-
culation to reduce HC (HydroCarbons) and CO
(Carbon Monoxide). Engine coolant is routed
through the base of the EGR valve to provide
additional cooling of the exhaust gas, which further
helps the reductions of emissions. The EGR valve
has a self-cleaning function. When the engine is
shut off, the EGR valve rotates twice to reduce
carbon deposits at the valve seat.
Overheat Production Mode
If the engine temperature is above 105ÉC (221ÉF)
and vehicle speed is above 40 km/h (25 MPH) the
ECM will limit fuel quantity for engine protection.
Limp-In Mode
The ECM utilizes different degrees of engine
limp-in. The ECM is able to limit engine rpm,
engine power output (turbo boost reduction), acti-
vate engine cooling fan or all of these functions
based on the type of fault that is detected. Critical
engine performance faults such as accelerator pedal
position sensor fault will result in a fixed idle speed
of approximately 680 rpm regardless of actual pedalposition. Other less critical faults will result in
power reduction throughout the full range of driv-
ing conditions.
Overspeed Detection Mode
If the ECM detects engine RPM that exceeds
5200 RPM, the ECM will set a DTC in memory,
limit engine RPM to no more than 2500 RPM, and
illuminate the MIL until the DTC is cleared.
After-Run Mode
The ECM transfers RAM information to ROM
and performs an Input/Output state check.
3.2.3 MONITORED CIRCUITS
The ECM is able to monitor and identify most
driveability related trouble conditions. Some cir-
cuits are directly monitored through ECM feedback
circuitry. In addition, the ECM monitors the voltage
state of some circuits and compares those states
with expected values. Other systems are monitored
indirectly when the ECM conducts a rationality test
to identify problems.
Although most subsystems of the engine control
module are either directly or indirectly monitored,
there may be occasions when diagnostic trouble
codes are not immediately identified. For a trouble
code to set, a specific set of conditions must occur
and unless these conditions occur, a DTC will not
set.
3.2.4 SKREEM OVERVIEW
The sentry key remote entry module system
(SKREEM) is designed to prevent unauthorized
vehicle operation. The system consists of a sentry
key remote entry module (SKREEM), ignition
key(s) equipped with a transponder chip and the
ECM. When the ignition switch is turned on, the
SKREEM interrogates the ignition key. If the igni-
tion key is Valid or Invalid, the SKREEM sends a
message to the ECM indicating ignition key status.
Upon receiving this message the ECM will termi-
nate engine operation or allow the engine to con-
tinue to operate.
3.2.5 SKREEM ON-BOARD DIAGNOSTICS
The SKREEM has been programmed to transmit
and monitor many different coded messages as well
as CAN Bus messages. This monitoring is called
On-Board Diagnostics. Certain criteria must be met
for a DTC to be entered into SKREEM memory. The
criteria may be a range of; input voltage, CAN Bus
message or coded messages to the SKREEM. If all
the criteria for monitoring a circuit or function are
met and a fault is detected, a DTC will be stored in
the SKREEM memory and the START ERROR indi-
cator will be turned on in the instrument cluster.
2
GENERAL INFORMATION