1999 DODGE RAM lock

Governor pressure is monitored electronically and is used to
control transmission shifting. Electronic control system consists of
Powertrain Control Module (PCM), governor pressure solenoid, governor
pressure sensor, transmission fluid temperature sensor, OD (Overdrive)\
OFF switch, Throttle Position (TP) sensor and output shaft speed
sensor.
NOTE: Governor pressure sensor may also be referred to as governor
pressure transducer. Transmission fluid temperature sensor
may also be referred to as transmission fluid temperature
thermistor. Output shaft speed sensor may also be referred to
as transmission shaft speed sensor or shaft speed sensor.
Transmission shifting is controlled by throttle pressure and
governor pressure. Governor pressure is generated by electronic
components through control of line pressure. Transmission will not
upshift into 4th gear under the following conditions:
* 3rd gear upshift is not complete.
* OD OFF switch is in OFF position.
* Throttle is at 3/4 to WOT position.
* Vehicle speed is too low for 3-4 upshift.
* Transmission fluid temperature is less than 50
F (10C) or
greater than 250F (121C).
* Battery temperature is less than 5F (-15C).
OPERATION
POWERTRAIN CONTROL MODULE (PCM)
The PCM controls Torque Converter Clutch (TCC) operation,
overdrive clutch operation and the governor pressure solenoid. The PCM
determines shift points and TCC operation based on input signals
received from transmission fluid temperature sensor, output shaft
speed sensor, Crankshaft Position (CKP) sensor, Vehicle Speed Sensor
(VSS), Throttle Position (TP) sensor and battery temperature sensor.\
There are 4 governor pressure curves programmed into the PCM.
Governor pressure curves allow the PCM to adjust governor pressure for
varying conditions. One governor pressure curve is used for operation
when transmission fluid temperature is at or less than 30
F (1C). The
second governor pressure curve is used for operation when transmission
fluid temperature is at or greater than 30
F (1C) during normal city
operation or highway driving. The third governor pressure curve is
used for operation during wide open throttle (WOT). The fourth
governor pressure curve is used for operation when transfer case is in
low range.
The PCM controls TCC operation by operating the lock-up
solenoid located on the valve body. Lock-up solenoid may be referred
to as TCC solenoid. If OD switch is in the ON position, the TCC will
lock-up once transmission is in 4th gear with vehicle speed greater
than 45 MPH. If OD switch is in the OFF position, the TCC will lock-up
once transmission is in 3rd gear with vehicle speed greater than 35
MPH at light throttle application. When OD switch is in the OFF
position, the OD light on instrument panel will be illuminated.
The PCM prevents TCC operation and overdrive operation when
transmission fluid temperature is less than 50
F (10C). If
transmission fluid temperature exceeds 260F (126C), the PCM will
cause a 4-3 downshift and engage the TCC. The OD light will be
illuminated when the downshift occurs. Transmission will not upshift
until transmission fluid temperature decreases to approximately 230
F
(110F).

The OD (Overdrive) OFF switch is located on instrument panel,\
to the right of steering column. The OD OFF switch controls overdrive
operation by delivering an input signal to PCM. The PCM uses this
signal for controlling operation of overdrive solenoid on the valve
body.
When overdrive switch is in the OFF position, OD light on
instrument panel will be illuminated and transmission will not upshift
into 4th gear for overdrive operation. When OD switch is in the ON
position, OD light on instrument panel will not be illuminated and
transmission will upshift into 4th gear for overdrive operation.
If OD switch is in the ON position, the TCC will lock-up when
transmission is in 4th gear with vehicle speed greater than 45 MPH. If
overdrive switch is in the OFF position, the TCC will lock-up when
transmission is in 3rd gear with vehicle speed greater than 35 MPH at
light throttle application.
THROTTLE POSITION (TP) SENSOR
The TP sensor delivers an input signal to the PCM to indicate
throttle position. The PCM uses this input signal for controlling TCC
operation, governor pressure and upshift into 4th gear for overdrive
operation.
TRANSMISSION FLUID TEMPERATURE SENSOR
NOTE: Transmission fluid temperature sensor may also be referred to
as transmission fluid temperature thermistor or transmission
fluid temperature sender.
Transmission fluid temperature sensor delivers an input
signal to the PCM to indicate transmission fluid temperature. The PCM
uses this input signal for controlling the TCC, overdrive operation
and governor pressure. Transmission fluid temperature sensor is
located on the valve body and is integral with governor pressure
sensor. See Fig. 1.
OUTPUT SHAFT SPEED SENSOR
NOTE: Output shaft speed sensor may also be referred to as
transmission shaft speed sensor or shaft speed sensor.
Output shaft speed sensor is located on overdrive unit
attached to rear of transmission. Output shaft speed sensor is mounted
above the lugs on park gear in the overdrive unit. Speed sensor input
signals are generated when lugs on park gear rotate past face of
sensor. Input signals are delivered to PCM. The PCM uses this input
signal for controlling transmission operation. The Vehicle Speed
Sensor (VSS) also serves as a back-up to the output shaft speed
sensor. The VSS signal is also an input to the PCM.
TROUBLE SHOOTING
* PLEASE READ THIS FIRST *
NOTE: For symptom trouble shooting, see appropriate AUTOMATIC
TRANSMISSION OVERHAUL article.
PRELIMINARY INSPECTION
Visually inspect all electrical wiring, looking for chafed,

Box (DRB) scan tool with appropriate cartridge for system
diagnosis. Other after-market scan tools may be used for
system diagnosis. The following procedure is for DRB scan
tool usage. Use scan tool manufacturer's instruction for
operating scan tool.
NOTE: Ensure battery is fully charged before proceeding with test.
1) Ensure ignition is off. Connect DRB to Data Link Connector
(DLC) located under driver's side of instrument panel. Using scan
tool, display all Diagnostic Trouble Codes (DTCs). Identify DTCs once
retrieved. See DIAGNOSTIC TROUBLE CODES (DTC) & DRB MESSAGES table.
2) If scan tool will not power up, check for loose cable
connections or faulty cable. If cable connections and cable are okay,
check voltage at DLC terminal No. 16. Voltage should be at least 11
volts. If voltage is not as specified, check wiring circuit and
necessary fuses. See WIRING DIAGRAMS.
3) If scan tool displays an error message, RAM TEST FAILURE,
CARTRIDGE ERROR, KEY PAD TEST FAILURE, or LOW OR HIGH BATTERY, this
indicates a scan tool failure.
4) If DTCs are displayed, perform appropriate test(s). See
DIAGNOSTIC TROUBLE CODES (DTC) & DRB MESSAGES table. If no DTCs are
displayed, see TROUBLE SHOOTING in appropriate AUTOMATIC TRANSMISSION
OVERHAUL article.
DIAGNOSTIC TROUBLE CODES (DTC) & DRB MESSAGES









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DTC DRB-III Scan Tool Message
P0711 .................. TRANS TEMP SENSOR, NO TEMP RISE AFTER START
P0712 ............................. TRANS TEMP SENSOR VOLTAGE TO LOW
P0713 ............................ TRANS TEMP SENSOR VOLTAGE TO HIGH
P0720 ..................... LOW OUTPUT SPEED SENSOR RPM ABOVE 15 MPH
P0740 .................... TORQ CONVERTER CLU, NO RPM DROP AT LOCKUP
P0743 ........ TORQUE CONVERTER CLUTCH SOLENOID/TRANS RELAY CIRCUITS
P0748 ........... GOVERNOR PRESSURE SOL CONTROL/TRANS RELAY CIRCUITS
P0751 ....................... OD SWITCH PRESSED (LO) MORE THAN 5 MIN\
P0753 ................ TRANS 3-4 SHIFT SOLENOID/TRANS RELAY CIRCUITS
P0783 ....................... 3-4 SHIFT SOL, NO RPM DROP @ 3-4 SHIFT
P1740 (1) .......................... TCC OR O/D SOLENOID PERFORMANCE
P1756 .................... GOV PRESS NOT EQUAL TO TARGET @ 15-20 PSI
P1757 ...................... GOV PRES ABOVE 3 PSI IN GEAR WITH 0 MPH
P1762 .................... GOV PRESS SEN OFFSET VOLTS TO LOW OR HIGH
P1763 ....................... GOVERNOR PRESSURE SENSOR VOLTS TO HIGH
P1763B ...................... GOVERNOR PRESSURE SENSOR VOLTS TO HIGH
P1764 ........................ GOVERNOR PRESSURE SENSOR VOLTS TO LOW
P1765 ..................... TRANS 12 VOLT SUPPLY RELAY CNTRL CIRCUIT
P1899 .......................... P/N SWITCH STUCK IN PARK OR ON GEAR
( 1) - BR body only.









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CLEARING DIAGNOSTIC TROUBLE CODES
After repairs have been performed, clear DTCs from PCM memory
using scan tool, following scan tool manufacturer's instructions.
NOTE: If malfunction is no longer present after DTC is stored in
PCM memory, the PCM will erase DTC after ignition has been
cycled at least 50 times. DTC may be cleared by using scan
tool. Follow scan tool manufacturer's instructions. DTCs may
also be cleared by disconnecting negative battery cable for a
period of time, but other vehicle control modules may also be

problem is found, measure resistance between output speed sensor
terminals. If resistance is 300-1200 ohms, go to next step. If
resistance is not as specified, replace output speed sensor.
7) Reconnect output speed sensor. Measure resistance between
ground and output speed sensor ground circuit at PCM harness
connector. If resistance is greater than 5 ohms, go to next step. If
resistance is not as specified, repair output speed sensor ground
circuit for a short to ground.
8) Measure resistance between ground and output speed sensor
signal circuit at PCM harness connector. If resistance is less than 5
ohms, repair output speed sensor signal circuit for a short to ground.
If resistance is not as specified, go to next step.
9) Measure resistance between output speed sensor signal
circuit and ground circuit at PCM harness connector. If resistance is
300-1200 ohms, replace PCM. If resistance is not as specified, go to
next step.
10) Disconnect output speed sensor harness connector. Measure
resistance of output speed sensor signal circuit between output speed
sensor harness connector and PCM harness connector. If resistance is
greater than 5 ohms, repair open in output speed sensor signal
circuit. If resistance is not as specified, repair open in output
speed sensor ground circuit.
11) Turn ignition on. Measure voltage between ground and
speed sensor ground circuit at PCM harness connector. Place gearshift
lever in each gear position and record voltage at each position. If
voltage is greater than one volt in any gear position, repair speed
sensor ground circuit for a short to power. If voltage is not as
specified, go to next step.
12) Raise and support vehicle. Start engine. Place gearshift
lever in "OD" position. Release brakes and allow wheels to rotate.
Using scan tool, monitor output speed sensor. While monitoring output
speed sensor, wiggle harness between output speed sensor and PCM. If
reading dropped towards zero while wiggling harness, repair
intermittent short or open in harness. If reading does not drop
towards zero while wiggling harness, problem is intermittent. See
INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is
complete.
DTC P0740: TORQ CONV CLU, NO RPM DROP AT LOCKUP
Circuit Description
Circuit is monitored continuously while key is on, and gear
selector is not in Park or Neutral. Code sets if Torque Converter
Clutch (TCC) does not achieve desired drop in RPM when TCC solenoid is\
near maximum duty cycle. A bad test 3 consecutive times is required to
set code.
Possible Causes
* Misfire trouble code set.
* Vehicle stalls (faulty TCC solenoid).
* TCC shaft seal/seal defective.
* Transmission fluid contaminated.
* TCC solenoid wiring harness defective.
* TCC defective.
* TCC hydraulic circuit damaged.
Diagnostic Procedure
1) Using scan tool, read DTCs. On all bodies except AB and WJ
bodies, go to next step. On AB and WJ bodies, if DTC SPECIFIC GOOD
TRIPS counter is not displayed or displayed count is not "0", go to
step 10). If DTC SPECIFIC GOOD TRIPS counter is displayed and
displayed count is "0", indicating DTC still exists, go to next step.

2) If any DTCs listed are present, perform appropriate
test(s). See TORQUE CONVERTOR CLUTCH (TCC) TESTS table. If no DTCs a\
re
present, go to next step.
TORQUE CONVERTOR CLUTCH (TCC) TESTS









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DTC DTC Message
P0122 (1) ................. THROTTLE POSITION SENSOR VOLTAGE TOO LOW
P0123 ( 1) ................ THROTTLE POSITION SENSOR VOLTAGE TOO HIGH
P1696 ( 1) .......................... PCM FAILURE EEPROM WRITE DENIED
P0743 ........ TORQUE CONVERTOR CLUTCH SOLENOID/TRANS RELAY CIRCUITS
( 2) ........................................................ MISFIRE
P0320 ( 1) ......................... NO CRANK REFERENCE SIGNAL AT PCM
( 1) - See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
( 2) - Perform appropriate misfire DTC test. See appropriate
SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.









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3) Check transmission fluid for proper level and for any
debris. Fill or repair transmission as necessary. If fluid level and
condition are okay, go to next step.
4) Start engine. Using scan tool, perform TCC SYSTEM TEST. If
vehicle does not stall, go to step 9). If vehicle stalls, go to next
step.
5) Using scan tool, perform GOV and 3-4 SHIFT VALVE SYSTEM
TEST. Select 4th gear. If vehicle stalls, go to next step. If vehicle
does not stall, go to step 7).
6) Turn ignition off. Replace TCC solenoid. Using scan tool,
perform GOV and 3-4 SHIFT VALVE SYSTEM TEST. Select 4th gear. If
vehicle stalls, problem in internal. Check for blocked passage. If
vehicle does not stall, testing is complete.
7) Turn ignition off. Remove oil pump and inspect reaction
shaft, input shaft and input seal. Repair transmission as necessary.
See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
transmission is okay, go to next step.
8) Inspect all related wiring and connectors. Repair as
necessary. If wiring and connectors are okay, see INACTIVE DTC
CONDITION under SELF-DIAGNOSTIC SYSTEM. Testing is complete.
9) Turn ignition off. Connect a pressure gauge to
transmission cooler OUT port. Start engine. Using scan tool, perform
TCC SYSTEM TEST. If pressure increases when TCC is actuated, go to
next step. If pressure does not increase, repair leaks or blockage in
hydraulic circuit, or repair valve body as necessary.
10) Turn engine off. Remove oil pump and inspect reaction
shaft, input shaft and input seal. Repair transmission as necessary.
See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
transmission is okay, there are no other potential causes remaining.
TCC is assumed to be defective. Replace torque converter.
DTC P0743: TORQUE CONV CLUTCH SOLENOID/TRANS RELAY CKT
NOTE: To test transmission temperature sensor, engine and
transmission temperature must be less than 85F (29C).
Circuit Description
Circuit is monitored continuously while key is on. Code sets
if voltage detected on Torque Converter Clutch (TCC) at the Powertrain\
Control Module (PCM) does not match desired voltage.
Possible Causes

If engine stalls, go to next step. If engine does not stall, go to
step 19).
17) Using scan tool, select GOV and 3-4 SHIFT VALVE SYSTEM
TEST. Select 4th gear. If engine stalls, go to next step. If engine
does not stall, go to step 23).
18) Replace TCC solenoid. Perform GOV and 3-4 SHIFT VALVE
SYSTEM TEST. Select 4th gear. If engine stalls, repair internal
problem. Check for internally blocked passages. See appropriate
AUTOMATIC TRANSMISSION OVERHAUL article. If engine does not stall,
test is complete.
19) Turn ignition off. Remove oil pump. Inspect reaction
shaft, input shaft and input seal. If any parts are damaged, repair as
necessary and go to next step. If all parts are okay, replace torque
converter.
20) Start engine. Perform GOV and 3-4 SHIFT VALVE SYSTEM
TEST. Select 4th gear. If engine stalls, go to next step. If engine
does not stall, go to step 23).
21) Turn ignition off. Replace TCC solenoid. Start engine.
Perform GOV and 3-4 SHIFT VALVE SYSTEM TEST. Select 4th gear. If
engine stalls, repair internal problem. Check for internally blocked
passages. See appropriate AUTOMATIC TRANSMISSION OVERHAUL article. If
engine does not stall, go to next step.
22) Turn ignition off. Remove oil pump. Inspect reaction
shaft, input shaft and input seal. If any parts are damaged, repair as
necessary and replace torque converter. If all parts are okay, test is
complete.
23) Turn ignition off. Remove oil pump. Inspect reaction
shaft, input shaft and input seal. If any parts are damaged, repair as
necessary and replace torque converter. If all parts are okay, go to
next step.
24) Record freeze frame data to determine conditions when
code was set. Using wiring diagram as a guide, inspect wiring and
connectors. Repair wiring harness as necessary. If wiring and
connectors are okay, go to next step.
25) Using scan tool, erase DTCs. Start engine. Attempt to
duplicate data and reset code. Road test vehicle maintaining a
constant throttle opening voltage of 1.15 volts, reach a speed of 60
MPH. Repeat road test 4 times. Note if DTC P1740 resets. If DTC P1740
resets, there are no other possible causes remaining. Problem is
considered to be an intermittent problem in wiring harness connector
or wire. See INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM.
Repair wiring harness as necessary. If DTC P1740 does not reset,
testing is complete.
DTC P1756: GOV PRESS NOT EQUAL TO TARGET @ 15-20 PSI
Circuit Description
Circuit is monitored continuously while key is on and engine
running, not in Park or Neutral position or with Malfunction Indicator
Light (MIL) illuminated. Code sets if governor pressure sensor output
is not 15-30 psi (1.0-2.1 kg/cm
) when requested pressure is 20-25 psi
(1.4-1.7 kg/cm) for 2.2 seconds. Test must fail 5 times to set code.
Possible Causes
* Other transmission codes are set.
* Solenoid pack connector 5 volt supply circuit open.
* Governor pressure sensor defective.
* Transmission fluid burnt or oil pan has excessive debris.
* Governor pressure out of range.
* Transmission leaking internally.
Diagnostic Procedures

6) Disconnect PNP switch harness connector. Measure
resistance of PNP switch sense circuit between Black PCM harness
connector C1 and PNP switch harness connector. If resistance is less
than 5 ohms, replace PNP switch. If resistance is not as specified,
repair open in PNP switch sense circuit.
7) Conditions required to set DTC P1899 are not present at
this time. Using scan tool, check and record FREEZE FRAME data. Ensure
"CAUSED BY DTC" "P" code matches code on DTC screen. Using wiring
diagram as a guide, inspect wiring and connectors. Repair wiring
harness as necessary. If wiring and connectors are okay, does not
reset, see INACTIVE DTC CONDITION under SELF-DIAGNOSTIC SYSTEM.
Testing is complete.
TEST VER-2A (EXCEPT DIESEL)
NOTE: If Powertrain Control Module (PCM) is replaced, correct
vehicle mileage and Vehicle Identification Number (VIN) must
be programmed into PCM to prevent Diagnostic Trouble Codes
(DTCs) from being set in Anti-Lock Brake System (ABS) modul\
e
and Supplemental Restraint System (SRS) module. To program
PCM and clear DTCs from ABS and SRS modules, proceed to
appropriate procedure listed below. On models equipped with a
Smart Key Immobilizer Module (SKIM), if replacing Powertrain
Control Module (PCM), secret key data must also be updated to\
enable engine starting. To update secret key data, proceed to
appropriate procedure listed below.
Procedure For Programming PCM & Clearing DTCs From ABS & SRS
Modules
Connect scan tool to Data Link Connector (DLC). Using scan
tool, enter correct VIN and mileage into PCM. Using scan tool
manufacturer's instructions, clear DTCs from ABS and SRS modules. Go
to step 1)).
Procedure For Updating Secret Key Data
Connect scan tool to Data Link Connector (DLC). Go to ENGINE
and then MISC menus on scan tool. Place SKIM in SECURED ACCESS MODE by
using appropriate Personal Identification Number (PIN) for this
vehicle. PIN may be obtained from owner, vehicle's invoice, or from
manufacturer. Select UPDATE THE SECRET KEY DATA. Data will be
transferred from Smart Key Immobilizer Module (SKIM) to PCM. Go to
step 1)).
1) Inspect vehicle to ensure all engine components are
connected. Reassemble and reconnect components as necessary. If test
is being performed after performing a NO TROUBLE CODE (NTC) test, go
to next step. If test is being performed after performing an OBD-II
TROUBLE CODE test, perform TEST VER-5A. If test is being performed
after any other TROUBLE CODE test, go to step 3).
2) Check if initial symptom still exists. If initial or
another symptom exists, repair is not complete. Check for Technical
Service Bulletins (TSBs) that apply to symptom and see appropriate
TEST NTC-1A: NO TROUBLE CODE TEST MENU in ENGINE PERFORMANCE, or
appropriate TROUBLE SHOOTING - NO CODES article in ENGINE PERFORMANCE
for diagnosis by symptom. If initial symptom no longer exists, test is
complete. Go to step 8).
3) If any DTCs have not been diagnosed, perform appropriate
test(s) see appropriate SELF-DIAGNOSTIC TESTS in ENGINE PERFORMANCE.
If all DTCs have been diagnosed and repaired, go to next step.
4) If Powertrain Control Module (PCM) has not been replaced,\
use scan tool to clear DTCs from PCM. Using scan tool, reset all
values in adaptive memory. To ensure no other DTCs remain, go to next
step.

5) If PCM has not been replaced, and TEST VER-2A is being
performed after an A/C relay control circuit DTC test, ensure A/C is
on and go to next step.
6) Road test vehicle for at least 5 minutes. Road test
vehicle at a speed of at least 40 MPH at some point during road test.
Stop vehicle. Turn engine off for at least 10 seconds. Start engine
and continue road test. Ensure transmission shifts through all gears.
After road test, turn engine off and go to next step.
7) Using scan tool, read DTCs. If any DTC returns, perform
appropriate test(s). If no DTCs return, test is complete. Go to next
step.
8) Turn ignition on, with engine off. Using scan tool, erase
DTCs. Turn ignition off. Disconnect scan tool. Test is complete.
TEST VER-2A (DIESEL)
NOTE: If Accelerator Pedal Position Sensor (APPS), battery, Engine
Control Module (ECM) or Powertrain Control Module (PCM) has\
been disconnected or replaced, APPS must be reprogrammed and
correct vehicle mileage and Vehicle Identification Number
(VIN) must be programmed into PCM to prevent Diagnostic
Trouble Codes (DTCs) from being set in Anti-Lock Brake System\
(ABS) module and Supplemental Restraint System (SRS) module\
.
To program PCM and clear DTCs from ABS and SRS modules,
proceed to appropriate procedure listed below. On models
equipped with a Smart Key Immobilizer Module (SKIM), if
replacing Powertrain Control Module (PCM), secret key data
must also be updated to enable engine starting. To update
secret key data, proceed to appropriate procedure listed
below.
CAUTION: DO NOT attempt to adjust screws or disassemble APPS. Settings
are preset at factory and are not intended to by changed.
Procedure For Programming APPS
Reassemble all components. Turn ignition switch to ON or RUN
position without starting engine. Slowly press accelerator pedal to
floor once and slowly release. This procedure programs APPS
calibration in ECM. Go to step 1)).
Procedure For Programming PCM & Clearing DTCs From ABS & SRS
Modules
Connect scan tool to Data Link Connector (DLC). Using scan
tool, enter correct VIN and mileage into PCM. Using scan tool
manufacturer's instructions, clear DTCs from ABS and SRS modules. Go
to step 1)).
Procedure For Updating Secret Key Data
Connect scan tool to Data Link Connector (DLC). Go to ENGINE
and then MISC menus on scan tool. Place SKIM in SECURED ACCESS MODE by
using appropriate Personal Identification Number (PIN) for this
vehicle. PIN may be obtained from owner, vehicle's invoice, or from
manufacturer. Select UPDATE THE SECRET KEY DATA. Data will be
transferred from Smart Key Immobilizer Module (SKIM) to PCM. Go to
step 1)).
1) If PCM has not been replaced, and TEST VER-2A (DIESEL) is\
being performed after a No Trouble Code (NTC) test, inspect vehicle to\
ensure all engine components are connected. Reassemble and reconnect
components as necessary. Check if initial symptom still exists. If
initial symptom exists, check for Technical Service Bulletins (TSBs)
that apply to vehicle and see TEST NTC-1A: NO TROUBLE CODE TEST MENU
in ENGINE PERFORMANCE, or appropriate TROUBLE SHOOTING - NO CODES