1999 HONDA CIVIC ECM reset

VTEC Control System
Troubleshooting Flowchart
tFtrsrl #ilH:::lj1t:"J:T,?ffnostic
rrouble code (Drc) Pr25e: A probrem in the vrEc Pressure switch circuit or
Reter to page 1 l-38 th roug h 1 1-55 before trou bleshooting.
* Road Test:Accelerate in 1st gear to an engine speed over 3,000 rpm(D16Y5 engine) or 6,000 rpm (D'16Y8 engine).Hold that engine speed for at least two seconds.It DTC P1259 is not repeated during the first road test, repeatthis test two more tames.
VTEC PRESSURE SWITCH 2PCONNECTOR
Terminal side ofmale terminals
Wire sid6 ol femalerermtnats
VTM
l1 (BLu/BLK)
f;-) |I
I
Y
I
The MIL has been reoorted on.DTC P1259 is sto.ed.
Check the VTEC Cont.ol Syst6m:1. Do the engine control module(ECM)/powertrain control module lPCM) Reset Procedure (see
section 11).2. Stan the engine.3. Warm up the engine to normaloperating temperature (cool-
ing fan comes on).4. Do the Boad Test.*Intermittont tailura, 3y3t.m is OKat thia time.Check for ooor connoctionr o.loose wirea at VTEC oiassurclwitch, VTEC solonoid valvo .ndECM/PCM,
ls OTC P1259 indicated?
Test rhe VTEC Prensure Switch:1. Turn the ignition switch OFF.2. Disconnect the VTEC Pressureswitch 2P connector.3. Check for continuity betweenVTEC pressure switch 2P con-nector terminal No. 1 and No.2.
Replace the VTEC preasure 3witch.ls there continuity?
Te3t the VTEC Pressure SwitchWire:1. Turn the ignition switch ON lll).2. Measure the voltage betweenVTEC press u re switch 2Pconnector No. l and bodyground.
In3poct for en opon or shod toground in thG wi.. bctwoon thoVTEC pro$ur6 switch rnd ECM/PCM l'96 - 9a: C15,'99 - 00: C101.lf tha wiro i3 OK,3ubrtitute aknown-good ECM/PCM andrecheck.
ls there battery voltage?
{To page 6'4i

VTEC Control SYstem
The scan tool indicates Diagnostic Trouble Code {DTC) Pl259:
VTEC Solenoid Valve circuit
Refer to page 1'l-38 through 11 55 before troubleshooting
Troubleshooting Flowchart
YES
A problem in the WEC Pressure Switch circuit or
* Road Test:Accelerate in 1st gear to an engine speed over 6,000 rp '
Hold that engine speed for at leasttwo seconos'
lf the DTC P1259 is not repeated during the first road test'
repeat this test two more times
VTEC PRESSURE SWITCH 2P
CONNECTOR
Terminalside ofmale termtnals
WM
/1 IBLU/BLKI
/ 1 Y------rt--------- l I
\1-/ |I
I
I1
Wire side of femaleterminals
(cont'd)
6-51
The MIL has been teported on.
DTC P1259 is siored.
Check the VTEC Control SYsiem:
1. Do the engine control module(ECM ) Reset Procedure (see
section 11).
2. Start the engine
3. Warm uP the engine to normal
operating temPerature (cool
ing fan comes on).
4. Do the Road Test.*lntermittent failure, sYstem is OK
at this time.Check for Poor connectlons or
loose wires at VTEC Pressureswilch. VTEC aolenoid valvo and
ECM.
ls DTC P1259 indicated?
Test the VTEC Pressure Switch:
1. Turn the ignition switch OFF.
2. Disconnect the VTEC Pressure
switch 2P connector.
3. Check for continuity between
VTEC pressure switch 2P con
nector telminal No 1 and
No.2.
Reolace the VTEC Pre3sure switch.
Test the VTEC Pressure Switch
Wire:1. Turn the ignition switch ON (ll).
2. N4easure the voltage between
VTEC press u re switch 2P
connector No. 1 and bodyground,
Inspect lor an open or short toground in the wire between the
VTEC orassure swilch and ECM
{c101.lf the wire i3 OK, substitute a
known-good ECM and recheck.
{To page 6 52)

Troubleshooting
Troubleshooting Procedures (cont,dl
ll, Engine Control Module (ECM)/powertrain Control Module (pCM) Reset procedure
NoTE: Resetting the EcM/PcM will erase any stored DTcs and any freeze data. lt will also restart all readiness codemonitors.
Either of the following actions will reset the ECM/PCM.
. Use the OBD ll scan tool or Honda pGM Tester to clear the EClM,s/pCM,s memory.
NorE: see the oBD ll scan tool or Honda PGM Tester user's manuals for specific operating instructions.
' Turn the ignition switch oFF. Remove the BACK uP (7.5 A) fuse from the under-hood fuse/relay box for 10 sec-onds.
NorE: Bemoving the BACK uP (7 5 A) fuse cancels the clock and the radio presets. Make note of the customer,spresets so you can reset then
lll. Final Procedure (this procedure must be done after any troubleshoottng)
1. Remove the SCS Service Connector if it is connected.
NoTE: If the Scs service connector is connected and there are no DTcs stored in the EcMipcM, the MtL will stayon when the ignition switch is turned ON 0l).
2. Do the ECM/PCM Reset procedure.
3. Turn the ignition switch OFF.
1-82

How to Read Flowcharts
A flowchart is designed to be used from start to final repair. lt's like a map showing you the shortest distance. But beware:
lf you go off the "map" anywhere but a "stop" symbol, you can easily get lost.
tSrARTl(bold type)
FanoNl
@
tsroP I
{bold type)
Describes the conditions or situation to start a troubleshooting flowchart.
Asks you to do something; perform a test, set up a condition etc.
Asks you about the result of an action, then sends you in the appropriate troubleshooting direction.
The end of a series of actions and decisions. describes a final repair action and sometimes directs you to
an earlier part of the flowchart to confirm your repair,
NOTE:
. The term "lntermittent Failure" is used in these charts, lt simply means a system may have had a failure. but it checks
out OK at this time. lf the Malfunction Indicator Lamp (MlL) on the dash does not come on, check for poor connections
or loose wires at all connectors related to the circuit that you are troubleshooting (see illustration below)'
. Most of the troubleshooting flowcharts have you reset the Engine Control Moduls (ECM)/Powertrain Control Module
(pCM) and try to duplicate the Diagnostic Trouble Code (DTC). lf the problem is intermittent and you can't duplicate the
code, do not continue though the flowchart. To do so will only result in confusion and, possibly, a needlessly replaced
ECM/PCM.
. ,,Open" and "Short" are common electrical terms. An open is a break in a wire or at a connection. A short is an acci-
dental connection of a wire to ground or to another wire. In simple electronics, this usually means something won't
work at all. In complex electronics (like ECM's/PCM'sl. this can sometim€s mean something works, but not the way it's
suDDosed to.
toosE
1 1-103

Manifold Absolute Pressure (MAP) Sensor ('96 Models)
The scan tool indicates Diagnostic Trouble Code (DTC) P0106: A mechanical problem (vacuum leak) in the
Manifold Absolute Pressure (MAP) Sensor system'
TheMAPsensorconvertsmanifoIdabsoIutepressureintoeiectricaIsigna|sandinpUtstheEcM/PcM'
OUTPUTVOLTAGE
(v13.5
3.0
2.5
2.0
1.5
1.0
0.5
0lin. Hgl GAUGE
- The MIL has been reported on- OTC P0106 is storod.- Or from Ptobable Cause Lisl.
Problom verificetion:1. Do the ECM/PCM Reset Pro-
cedure.2. Start the engine and keep
engine speed at 1,000 rpm for
one minute with the transmis'
sion in @ or I Position {Mff
in neutral).
ls DTC P0106 indicated?
Check tor vacuum leakage or
blockage between the MAP sen'
sor and throftle bodyCheck the MAP sensor outPut:
1. Turn the ignition switch OFF
2. Turn the ignition switch ON (ll).
3. Check the MAP with the scan
tool.ls there leakage or blockage?
Chock the MAP s€nsol output:
1. Stop the engane.2. Turn the ignition switch ON (ll).
3. Check the MAP with the scan
tool.
READING300(mm Hgl
(To page 11 116)
{cont'd)ll,(To page 11-116)
1 1-1 15

Primary Heated Oxygen Sensor {Primary HO2SI (Sensor 1)
t('96 - 98 Models except Dl6Y5 engine with M/Tl
The Heated Oxygen Sensor (HO2S) detects the oxygen content in the exhaust gas and signals the ECM/PCM. In operation,
the ECM/PCM receives the sjgnals from the sensor and varies the duration during which fuel is injected To stabilize the
sensor,s output, the sensor has an internal heater. The Primary HO2S (Sensor 1) is installed in the exhaust manifold.
HO2S:
VOLTAGE {VI
The scan tool indicates Diagnostic Trouble Code (DTC) P0131; A low voltage
Oxygen Sensor (H02S) (Sensor 1) circuit.
R|cH-AIR- - LEANFUELRANO
problem in the Primary Heated
SENSOR
ztRcoNlA
The MIL has be€n teported on.DTC P0131 is siorcd.
Problom verificalion:1. Do the ECM/PCM Reset Pro'
cedure.2. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on,3. Test-drive with the A/T in Eposition (M/T in 4th gear)
4. Check the Primary HO2S(Sensor 1) output voltage with
the scan tool during accelera-
tion using wide open throttle.
lntcrmift€nt failura, 3Y3tem is OKat this tims. Check for Poor con-nections or loo3e wi.o3 at C123(Primlry HO2S, 3sn3or 1) and
ECM/PCM,
(To page 1I-140)
{cont'd)
1 1-139

Primary Heated Oxygen Sensor (Primary- Fjq?S) (Sensor 1l
('99 - 0b Models exiept D16Y5 engine with M/T)
TheHeatedoxygensensors(Ho2S)detecttheoxygencontentintheexhaustgasandsigna|stheEcM/PcM'|noperation,
the EcM/pcM receives the signars from the sensor and varies the duration during which fuel is injected. To stabilize the
sensor,soutput,thesensornasaninternaIheater.ThePrimaryHo2S(sensorl)isinsta|ledinexhaustmanifo|d(D16Y8.
81642 engine: exhaust PiPe A)
SENSORTERMINALSVOLTAG€ (VI
HEATERTERMINALS
The scan tool indicates Diagnostic Trouble Code (DTC) P0131: A low voltage
Oxygen Sensor (HO2S) (Sensor 1) circuit
RICH+ AIR- - LEANFUELRATIO
problem in the Primary Heated
HEATER
- The MIL has been t€Ported on.- DTC P013'l is stored.
Problem veritication:1. Do the ECM/PCM Reset Pro-
2. Start the engine. Hold the
engine at 3,000 rpm wrth no
load (in Park or neutral) until
the radiator fan comes on
3. Check the PrimarY HO2S
lSensor 1) output voltage wath
the scan tool during accelera
tion using wide open throttle
lntermittont f.ilure, 3ystem i3 OK
at thi3 time. Check tor Poor con'
nections or loose wires el C123
{Primary HO2S, Sensor 1) and
ECM/PCM.
Does the voltage stay at 0 5 v
or less?
Check the fuel pressLlre (see Page11,109).
(To page 11 142)(cont'd)
11-141

Primary Heated Oxygen Sensor (Primary HO2SI (Sensor 1)
('96 - 9b Models except Dl6Y5 engine with M/Tl
PHO29IWHT}
The scan tool indicates Diagnostic Trouble Code (DTC) P0132: A high voltage problem in the Primary Heated
Oxygen Sensor (Primary H02S) (Sensor'l) circuit.
PRIMARY HO2S (Sonso. 'll 4P CONNECToR
tc123t
sG2IGRN/BLKI
Wire side ot female terminals
ECM/PCM CONNECTOR D I16PI
JUMPER WIRE
PHO2S (WHT}SG2 IGRN/BLKI
Wire side of tem6le terminals
Probl€m verification:1. Do the ECM/PCM Reset Pro-
cedure.2. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on
3. Test-drive with the A/T in Eposition (M/T in 4th gear)
4. Check the PrimarY HO2S(Sensor 1) oLltPut voltage with
the scan tool during decelera'tion using completely closed
throttle.
Int.rmittont fiilur., system it OK
at thb timo. Chock for Poot con-
nections or loo3a wir63 at Cl23
lPrimarY HO2S, SensoJ 1l .nd
ECM/PCM.
Does the voltage stay at 1.0 V
or more?
Check for an open in the Primary
HO2S:1. Turn the ignition switch OFF.
2. Disconnect the Primary HO2S(Sensor 1) 4P connector'
3. Connect the PrimarY HO25
lSensor l) 4P connector termi-
nals No. 1 and No. 2 with a
4. Turn the ignition switch ON (ll).
5. Check the PrimarY H02S(Sensor 1i outPut voltage with
the scan tool.
lsthere 1.0 V or more?
Check for an open in the wiro
{PHO2S line):1. Turn the ignition switch OFF.
2. Connect EcM/PcM connector
terminals D7 and D11 with ajumper wrre,3. Turn the ignition switch ON lll)4. Check the PrimarY HO2S(Sensor 1) output voltage withthe scan tool,
Replir open in tho wirc b€twccnECM/PCM lo?) and Prim!.Y
HO2S lsonsor 1).ls there 1.0 V or more?
Substitute a known-good ECM/PCM and recheck. lf 3ymptom/indicetion goos awey, roplacethe oliginal ECM/PCM.
11-143