1998 OPEL FRONTERA engine coolant

6E–5 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Conditions for Clearing the MIL/DTC 6E–159. . . . .
Diagnostic Aids 6E–159. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1562
(Flash DTC 35) System Voltage Too Low
at Cranking 6E–160. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 6E–160. . . . . . . . . . . . . . . . . . . . .
Action Taken When the DTC Sets 6E–160. . . . . . .
Conditions for Clearing the MIL/DTC 6E–160. . . . .
Diagnostic Aids 6E–160. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1587
(Flash DTC 25) Brake SW Malfunction 6E–161. . . .
Circuit Description 6E–161. . . . . . . . . . . . . . . . . . . . .
Action Taken When the DTC Sets 6E–161. . . . . . .
Conditions for Clearing the MIL/DTC 6E–161. . . . .
Diagnostic Aids 6E–161. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1588
(Flash DTC 25) Brake SW Malfunction 6E–163. . . .
Circuit Description 6E–163. . . . . . . . . . . . . . . . . . . . .
Action Taken When the DTC Sets 6E–163. . . . . . .
Conditions for Clearing the MIL/DTC 6E–163. . . . .
Diagnostic Aids 6E–163. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0601
(Flash DTC 55) ECM Checksum Error 6E–165. . . . .
Action Taken When the DTC Sets 6E–165. . . . . . .
Conditions for Clearing the MIL/DTC 6E–165. . . . .
Diagnostic Aids 6E–165. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0650
(Flash DTC 77) Check Engine Lam Circuit
Open/Short 6E–166. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 6E–166. . . . . . . . . . . . . . . . . . . . .
Action Taken When the DTC Sets 6E–166. . . . . . .
Conditions for Clearing the MIL/DTC 6E–166. . . . .
Diagnostic Aids 6E–166. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P0654
(Flash DTC 27) Tachometer Circuit
Open/Short 6E–168. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 6E–168. . . . . . . . . . . . . . . . . . . . .
Action Taken When the DTC Sets 6E–168. . . . . . .
Conditions for Clearing the MIL/DTC 6E–168. . . . .
Diagnostic Aids 6E–168. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1655
(Flash DTC 17) Thermo Relay Circuit
Open/Short 6E–170. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 6E–170. . . . . . . . . . . . . . . . . . . . .
Action Taken When the DTC Sets 6E–170. . . . . . .
Conditions for Clearing the MIL/DTC 6E–170. . . . .
Diagnostic Aids 6E–170. . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Trouble Code (DTC) P1657
(Flash DTC 76) ECM Main Relay Circuit
Open/Short 6E–172. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 6E–172. . . . . . . . . . . . . . . . . . . . .
Action Taken When the DTC Sets 6E–172. . . . . . .
Conditions for Clearing the MIL/DTC 6E–172. . . . .
Diagnostic Aids 6E–172. . . . . . . . . . . . . . . . . . . . . . . . Diagnostic Trouble Code (DTC) P1589
(Flash DTC 47) Transmission SW Circuit
Open/Short 6E–174. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit Description 6E–174. . . . . . . . . . . . . . . . . . . . .
Action Taken When the DTC Sets 6E–174. . . . . . .
Conditions for Clearing the MIL/DTC 6E–174. . . . .
Diagnostic Aids 6E–174. . . . . . . . . . . . . . . . . . . . . . . .
Symptom Diagnosis 6E–176. . . . . . . . . . . . . . . . . . . . .
Default Matrix Table 6E–199. . . . . . . . . . . . . . . . . . . . .
On–Vehicle Service Camshaft Position
(CMP) Sensor 6E–201. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–201. . . . . . . . . . . . . . . . . . . .
Inspection Procedure 6E–201. . . . . . . . . . . . . . . . . .
Installation Procedure 6E–201. . . . . . . . . . . . . . . . . .
Crankshaft Position (CKP) Sensor 6E–202. . . . . . . . .
Removal Procedure 6E–202. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–202. . . . . . . . . . . . . . . . . .
Engine Coolant Temperature (ECT) Sensor 6E–203.
Removal Procedure 6E–203. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–203. . . . . . . . . . . . . . . . . .
Intake Air Temperature (IAT) Sensor 6E–203. . . . . . .
Removal Procedure 6E–203. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–204. . . . . . . . . . . . . . . . . .
Manifold Absolute Pressure (MAP) Sensor 6E–204.
Removal Procedure 6E–204. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–205. . . . . . . . . . . . . . . . . .
Oil Temperature (OT) Sensor 6E–205. . . . . . . . . . . . .
Removal Procedure 6E–205. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–206. . . . . . . . . . . . . . . . . .
Malfunction Indicator Lamp (MIL) 6E–206. . . . . . . . . .
Removal and Installation Procedure 6E–206. . . . . .
Engine Control Module (ECM) 6E–206. . . . . . . . . . . .
Service Precaution 6E–206. . . . . . . . . . . . . . . . . . . .
Electrostatic Discharge (ESD) Damage 6E–206. . .
Removal Procedure 6E–207. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–208. . . . . . . . . . . . . . . . . .
EEPROM 6E–208. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 6E–208. . . . . . . . . . . . . . . . . . . .
Functional Check 6E–208. . . . . . . . . . . . . . . . . . . . . .
Intake Throttle Position (ITP) Sensor 6E–208. . . . . . .
Removal Procedure 6E–208. . . . . . . . . . . . . . . . . . . .
Function Check 6E–209. . . . . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–209. . . . . . . . . . . . . . . . . .
Vehicle Speed Sensor (VSS) 6E–210. . . . . . . . . . . . .
Removal Procedure 6E–210. . . . . . . . . . . . . . . . . . . .
Inspection Procedure 6E–210. . . . . . . . . . . . . . . . . .
Installation Procedure 6E–210. . . . . . . . . . . . . . . . . .
Air Cleaner/Air Filter 6E–211. . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–211. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–211. . . . . . . . . . . . . . . . . .
Accel Position (AP) Sensor 6E–211. . . . . . . . . . . . . . .
Removal Procedure 6E–211. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–212. . . . . . . . . . . . . . . . . .
Accelerator Pedal Replacement 6E–212. . . . . . . . . . .

6E–6
4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Removal Procedure 6E–212. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–212. . . . . . . . . . . . . . . . . .
Fuel Filter Cap 6E–213. . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 6E–213. . . . . . . . . . . . . . . . . . . .
Inspection Procedure 6E–213. . . . . . . . . . . . . . . . . .
Fuel Filter 6E–213. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal and Installation Procedure 6E–213. . . . . .
Fuel Gauge Unit 6E–213. . . . . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–213. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–214. . . . . . . . . . . . . . . . . .
Fuel Injectors 6E–214. . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal and Installation Procedure 6E–214. . . . . .
Fuel Temperature Sensor 6E–214. . . . . . . . . . . . . . . .
Removal Procedure 6E–214. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–215. . . . . . . . . . . . . . . . . .
Rail Pressure (RP) Sensor 6E–216. . . . . . . . . . . . . . .
Removal Procedure 6E–216. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–216. . . . . . . . . . . . . . . . . .
Fuel Tank 6E–216. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–216. . . . . . . . . . . . . . . . . . . .
Throttle Body (TB) 6E–217. . . . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–217. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–217. . . . . . . . . . . . . . . . . .
Air Conditioning (A/C) Relay 6E–217. . . . . . . . . . . . . .
Removal Procedure 6E–217. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–217. . . . . . . . . . . . . . . . . .
Exhaust Gas Recirculation (EGR) Vacuum
Switch Valve (VSV) 6E–217. . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–217. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–218. . . . . . . . . . . . . . . . . .
Electronic Vacuum Regurating Valve (EVRV) 6E–219
Removal Procedure 6E–219. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–220. . . . . . . . . . . . . . . . . .
Wiring and Connectors 6E–220. . . . . . . . . . . . . . . . . . .
Wiring Harness Service 6E–220. . . . . . . . . . . . . . . .
Connectors and Terminals 6E–220. . . . . . . . . . . . . .
Wire Harness Repair: Twisted Shielded
Cable 6E–220. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–220. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–221. . . . . . . . . . . . . . . . . .
Twisted Leads 6E–221. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–221. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–222. . . . . . . . . . . . . . . . . .
Weather-Pack Connector 6E–223. . . . . . . . . . . . . . . . .
Tools Required 6E–223. . . . . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–223. . . . . . . . . . . . . . . . . . . . Installation Procedure 6E–223. . . . . . . . . . . . . . . . . .
Com-Pack III 6E–224. . . . . . . . . . . . . . . . . . . . . . . . . . .
General Information 6E–224. . . . . . . . . . . . . . . . . . . .
Metri-Pack 6E–224. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tools Required 6E–224. . . . . . . . . . . . . . . . . . . . . . . .
Removal Procedure 6E–224
. . . . . . . . . . . . . . . . . . . .
Installation Procedure 6E–224. . . . . . . . . . . . . . . . . .
General Description
(ECM and Sensors) 6E–225. . . . . . . . . . . . . . . . . . . . .
57X Reference ECM Input 6E–225. . . . . . . . . . . . . .
A/C Request Signal 6E–225. . . . . . . . . . . . . . . . . . . .
Crankshaft Position (CKP) Sensor 6E–225. . . . . . .
Camshaft Position (CMP) Sensor and
Signal 6E–225. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coolant Temperature (ECT) Sensor 6E–225
Electrically Erasable Programmable Read
Only Memory (EEPROM) 6E–225. . . . . . . . . . . . . .
Intake Air Temperature (IAT) Sensor 6E–225. . . . .
Manifold Absolute Pressure (MAP) Sensor 6E–226
Engine Control Module (ECM) 6E–226. . . . . . . . . . .
ECM Function 6E–226. . . . . . . . . . . . . . . . . . . . . . . . .
ECM Components 6E–226. . . . . . . . . . . . . . . . . . . . .
ECM Voltage Description 6E–226. . . . . . . . . . . . . . .
ECM Input/Outputs 6E–226. . . . . . . . . . . . . . . . . . . .
ECM Service Precautions 6E–227. . . . . . . . . . . . . .
Intake Throttle Position (ITP) Sensor 6E–227. . . . .
Transmission Range Switch 6E–227. . . . . . . . . . . . .
Accelerator Position Sensor (AP) 6E–227. . . . . . . .
Aftermarket Electrical and Vacuum
Equipment 6E–227. . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrostatic Discharge Damage 6E–227. . . . . . . . .
General Description (Air Induction) 6E–228. . . . . . . .
Air Induction System 6E–228. . . . . . . . . . . . . . . . . . .
General Description (Fuel Metering) 6E–228. . . . . . .
Deceleration Mode 6E–228. . . . . . . . . . . . . . . . . . . .
Fuel Injector 6E–228. . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Metering System Components 6E–228. . . . . .
A/C Clutch Diagnosis 6E–228. . . . . . . . . . . . . . . . . . . .
A/C Request Signal 6E–228. . . . . . . . . . . . . . . . . . . .
General Description Exhaust Gas
Recirculation (EGR) System 6E–228. . . . . . . . . . . . .
EGR Purpose 6E–228. . . . . . . . . . . . . . . . . . . . . . . . .
Fuse and Relay Panel
(Underhood Electrical Center) RHD 6E–229. . . . . . .
Fuse and Relay Panel
(Underhood Electrical Center) LHD 6E–230. . . . . . .

6E–7 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Specification
Tightening Specifications
Application
NꞏmKgꞏmLb Ft.Lb In.
Camshaft Position Sensor Retaining Screw90.9—78
Crankshaft Position Sensor Mounting Bolt90.9—78
Engine Coolant Temperature Sensor191.914—
Throttle Body Mounting Nuts202.014—
VSS Retaining Bolt161.612—
MAP Sensor Screw40.4—35
EGR VSV Bolts80.8—69
Fuel Temp Sensor191.914—
Oil Temp Sensor Bolt191.914—
Rail Pressure Sensor Bolt202.014—

6E–17 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
ECM Pinout Table, 32-Way Connector – J2 BLUE – Lower
060RW137
J2 – BLUE
PINSIGNAL
17COOLANT TEMP OUT
18OIL TEMPERATURE
19TDC/CAM
20SPARE ANALOG 2
21INTAKE AIR TEMPERATURE
22+5VRTN2
23BOOST/INLET PRESSURE
24+5VRTN3
25ACCELERATOR POSITION
26+5VRTN1
27EGR VACUUM PRESSURE
28INTAKE SM S2T
29DIAGNOSTIC REQUEST SW
30COOLANT TEMPERATURE
31A/T PARK SW
32CRANKSHAFT

6E–19 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Component Locator
Engine Component Locator Table
F06RW051
NumberNameLocation
1AP (Accelerator Pedal Position) SensorAP Bracket
2CKP (Crankshaft Position) SensorInside the right front flywheel Housing
3Oil RailMounted on the camshaft carrier
4Oil (Rail) Pressure SensorMounted on the Oil Rail
5OT (Oil Temperature) SensorMounted on the Oil Rail
6Fuel InjectorIn the Cylinder Head Cover
7Fuel Return OrificeInside the Cylinder Head
8FT (Fuel Temperature) SensorFuel Return Adaptor
9IntercoolerOn the Cylinder Head Cover
10Intake Throttle MotorBehind the Intake Manifold
11Intake ThrottleBehind the Intake Manifold
122 Way Check ValveBelow the Intake Manifold
13VSV (Vacuum Switching Valve)At the left Cylinder Body
14EGR Pressure SensorBelow the Intake Manifold
15Fuel FilterAt the left Engine Room
16CMP (Camshaft Position) SensorOn the forward of Timing Gear Case
17IAT (Intake Air Temperature) SensorBelow the Intake Manifold
18ECT (Engine Coolant Temperature)Thermostat Housing
19High Pressure Oil PumpOn the back Timing Gear Case

6E–23 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Abbreviations Charts
List of abbreviations which may be used in this section.
Abbreviations
Te r mAbbreviationsTe r m
A/CAir ConditionerBLKBlack
A/TAutomatic TransmissionBLUBlue
ACCAccessoryBRNBrown
APAccel PositionGRNGreen
ASMAssemblyGRYGray
CKPCrank PositionLT B L ULight Blue
CMPCam PositionLT G R NLight Green
DLCData Link ConnectorORNOrange
DTCDiagnosis Trouble CodePNKPink
DVMDigital Volt MeterREDRed
ECMEngine Control ModuleVIOViolet
ECTEngine Coolant TemperatureWHTWhite
EGRExhaust Gas RecircurationYELYe l l o w
EVRVElectric Vacuum Regulating Valve
EXHExhaust
FTFuel Temperature
IATIntake Air Temperature
IGIgnition
ITPIntake Throttle Position
M/TManual Transmission
MAPManifold Absolute Pressure
MILMulfunction Indicator Lamp
OBDOn-Board Diagnostic
OTOil Temperature
QOSQuick on Start System
QWSQuick Warming-Up System
RPRail Pressure
RPCVRail Pressure Control Valve
SRSSupplemental Restraint System
STStart
SWSwitch
TEMPTemperature
TODTorque on Demand
VSSVehicle Speed Sensor
VSVVacuum Switching Valve
HEUIHydraulically Actuated Electronically Controlled Unit
InjectorInjector

6E–25 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
General Service Information
Serviceability Issues
Non-OEM Parts
All of the OBD diagnostics have been calibrated to run
with OEM parts. Accordingly, if commercially sold sensor
or switch is installed, it makes a wrong diagnosis and turn
on the MIL (“Check Engine” lamp).
Aftermarket electronics, such as cellular phones,
stereos, and anti-theft devices, may radiate EMI into the
control system if they are improperly installed. This may
cause a false sensor reading and turn on the MIL (“Check
Engine” lamp).
Poor Vehicle Maintenance
The sensitivity of OBD diagnostics will cause the MIL
(“Check Engine” lamp) to turn on if the vehicle is not
maintained properly. Restricted oil filters, fuel filters, and
crankcase deposits due to lack of oil changes or improper
oil viscosity can trigger actual vehicle faults that were not
previously monitored prior to OBD. Poor vehicle
maintenance can not be classified as a “non-vehicle
fault”, but with the sensitivity of OBD diagnostics, vehicle
maintenance schedules must be more closely followed.
Related System Faults
Many of the OBD system diagnostics will not run if the
ECM detects a fault on a related system or component.
Visual/Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:
Inspect all vacuum hoses for punches, cuts,
disconnects, and correct routing.
Inspect hoses that are difficult to see behind other
components.
Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.
Basic Knowledge of Tools Required
NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.
Serial Data Communications
Class II Serial Data Communications
This vehicle utilizes the “Class II” communication system.
Each bit of information can have one of two lengths: longor short. This allows vehicle wiring to be reduced by
transmitting and receiving multiple signals over a single
wire. The messages carried on Class II data streams are
also prioritized. If two messages attempt to establish
communications on the data line at the same time, only
the message with higher priority will continue. The device
with the lower priority message must wait.
On this vehicle the Tech 2 displays the actual values for
vehicle parameters. It will not be necessary to perform
any conversions from coded values to actual values.
On-Board Diagnostic (OBD)
On-Board Diagnostic Tests
A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:
The diagnostic test has been completed since the last
ignition cycle.
The diagnostic test has passed during the current
ignition cycle.
The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:
The diagnostic test has been completed since the last
ignition cycle.
The fault identified by the diagnostic test is currently
active.
The fault has been active during this ignition cycle.
The operating conditions at the time of the failure.
Comprehensive Component Monitor
Diagnostic Operation
Comprehensive component monitoring diagnostics are
required to operate engine properly.
Input Components:
Input components are monitored for circuit continuity and
out-of-range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable. Accel
Position (AP) sensor that indicates high throttle position
at low engine loads or MAP voltage. Input components
may include, but are not limited to the following sensors:
Intake Air Temperature (IAT) Sensor
Crankshaft Position (CKP) Sensor
Intake throttle Position (ITP) Sensor
Engine Coolant Temperature (ECT) Sensor
Camshaft Position (CMP) Sensor
Manifold absolute Pressure (MAP) Sensor
Accel Position Sensor
Fuel Temp Sensor
Rail Pressure Sensor
Oil Temp Sensor
EGR Pressure Sensor
Vehicle Speed Sensor

6E–27 4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS
Non-Emissions related
Dose not request illumination of any lamp
Stores a History DTC on the first trip with a fail
Stores Fail Record when test fails
Updates the Fail Record each time the diagnostic test
fails
Storing and Erasing Freeze Frame Data and Failure
Records
The data captured is called Freeze Frame data. The
Freeze Frame data is very similar to a single record of
operating conditions. Whenever the MIL is illuminated,
the corresponding record of operating conditions is
recorded to the Freeze Frame buffer.
Data from these faults take precedence over data
associated with any other fault. The Freeze Frame data
will not be erased unless the associated history DTC is
cleared.
Each time a diagnostic test reports a failure, the current
engine operating conditions are recorded in the
Failure
Records
buffer. A subsequent failure will update the
recorded operating conditions. The following operating
conditions for the diagnostic test which failed
typically
include the following parameters:
Engine Speed
Engine Load
Engine Coolant Temperature
Vehicle Speed
Intake Throttle Position
MAP
Injector Base Pulse Width
Loop Status
Data Link Connector (DLC)
The provision for communication with the contorl module
is the Data Link Connector (DLC). It is located at behind
the lower front instrument panel. The DLC is used to
connect to a Tech 2. Some common uses of the Tech 2
are listed below:
Identifying stored Diagnostic Trouble Codes (DTCs).
Clearing DTCs.
Performing out put control tests.
Reading serial data.
060RW046
Verifying Vehicle Repair
Verification of vehicle repair will be more comprehensive
for vehicles with OBD system diagnostic. Following a
repair, the technician should perform the following steps:
1. Review and record the Fail Records and/or Freeze
Frame data for the DTC which has been diagnosed.
2. Clear DTC(s).
3. Operate the vehicle within conditions noted in the Fail
Records and/or Freeze Frame data.
4. Monitor the DTC status information for the specific
DTC which has been diagnosed until the diagnostic
test associated with that DTC runs.
Following these steps are very important in verifying
repairs on OBD systems. Failure to follow these steps
could result in unnecessary repairs.
Reading Flash Diagnostic Trouble Codes
The provision for communicating with the Engine Control
Module (ECM) is the Data Link Connector (DLC). The
DLC is located in the front console box. It is used in the
assembly plant to receive information in checking that the
engine is operating properly before it leaves the plant.
The diagnostic trouble code(s) (DTCs) stored in the
ECM’s memory can be read either through a hand-held
diagnostic scanner plugged into the DLC or by counting
the number of flashes of the “Check Engine” Malfunction
Indicator Lamp (MIL) when the diagnostic test terminal of
the DLC is grounded. The DLC terminal “6” (diagnostic
request) is pulled “Low” (grounded) by jumpering to DLC
terminal “4”, which is a ground wire.
This will signal the ECM that you want to “flash” DTC(s), if
any are present. Once terminals “4” and “6” have been
connected, the ignition switch must be moved to the “ON”
position, with the engine not running.
The “Check Engine”MIL will indicate a DTC three times if
a DTC is present. If more than one DTC has been stored