Engine Controls - Tests W/codes - 2.2L: Diagnosis Toyota Celica T200

RETRIEVING TROUBLE CODES

Note. Trouble codes may be retrieved using Toyota scan tester in Normal Mode or Test Mode.

Note. Normal Mode is used to retrieve trouble code from Electronic Control Module (ECM) to determine problem area. Test Mode is used to check for trouble codes when operating vehicle to simulate conditions in which trouble code was set. Test mode contains a higher sensing ability to detect malfunctions. Test Mode helps determine malfunctions caused by poor electrical connections, which are difficult to determine using Normal Mode. Test Mode also checks for malfunction in starter signal circuit, A/C switch signal and Park/Neutral switch signal.

Note. The Malfunction Indicator Light (MIL) on the instrument panel may also be referred to as CHECK ENGINE light.

Test Mode

1. Before retrieving trouble code(s), verify MIL on instrument panel comes on with ignition on and engine off. The MIL should go off when engine is started.
2. Check bulb circuit on instrument panel and wiring circuit between MIL and ECM. See appropriate wiring diagram information in «WIRING DIAGRAMS»(ref-21370) article. See «ECM LOCATION»(ref-21372-S00087128932001010300000).
3. Ensure battery voltage is greater than 11 volts and charging system is okay. Apply parking brake. Shift the transmission/transaxle to Neutral (M/T) or Park (A/T). Turn A/C and all accessories off. Ensure throttle is in idle position and ignition is off. NOTE: Test Mode will not operate if jumper wire is installed between terminals TE2 and E1 in Data Link Connector (DLC) after ignition is turned on.
4. Install Jumper Wire (SST 09843-18020) between terminals TE2 and E1 in Data Link Connector (DLC) with ignition off. (Scheme 120)
5. Turn ignition on with engine off. Test Mode is operational if MIL on instrument panel flashes.
6. If MIL fails to flash, check TE2 wiring circuit. See appropriate TE1 & TE2 DIAGNOSTIC CIRCUIT CHECK chart under TROUBLE CODE CHARTS. See «ECM LOCATION»(ref-21372-S00087128932001010300000).
7. Drive vehicle at a speed greater than 6 MPH. ECM will set Trouble Codes 42 and 43 if vehicle is not driven. Try to simulate conditions of driveability complaint described by customer, and note when MIL comes on. This indicates when problem exists.
8. Stop vehicle, but DO NOT turn engine off. Install jumper wire between terminals TE1 and E1 in DLC. (Scheme 120) Count number of flashes from MIL on instrument panel. If system is operating properly (with no trouble codes), MIL will flash continuously and evenly. (Scheme 121)
9. If trouble code exists, digits of trouble code will be flashed at approximately 1/2-second intervals. A 1 1/2-second pause separates first and second digits of code. (Scheme 121)
10. If more than one trouble code is stored, a 2 1/2-second pause will occur before next trouble code is flashed. Once all trouble codes are displayed, a 4 1/2-second pause will occur, then trouble code(s) will be repeated. Trouble codes are displayed in order of smallest to largest. NOTE: On all models, Trouble Code 51 will normally be displayed if automatic transmission/transaxle is in any gear except Park or Neutral, A/C is turned on, or accelerator pedal is depressed.
11. After trouble code(s) is retrieved, remove jumper wires to exit Test Mode. See «NOTES ON TROUBLE CODES»(ref-21372-S33337710902001010300000). For additional information on trouble codes, see «TROUBLE CODE DIAGNOSTIC HINTS»(ref-21372-S11789728212001010300000) table under SELF-DIAGNOSTIC SYSTEM and appropriate «TROUBLE CODE IDENTIFICATION»(ref-21372-S13888618922001010300000) table under TROUBLE CODE IDENTIFICATION.

Note. The MIL may not come on if certain trouble code is set when in Test Mode. See appropriate TROUBLE CODE IDENTIFICATION table under TROUBLE CODE IDENTIFICATION .

Note. To repair failure causing trouble code, refer to proper trouble code chart under TROUBLE CODE CHARTS. Once repairs for trouble code are made, trouble code must be cleared from ECM memory. See CLEARING TROUBLE CODES .

Scheme 120

Scheme 121

NOTES ON TROUBLE CODES

1. When certain trouble codes occur, MIL on instrument panel will not come on. For designation of MIL operation on certain trouble codes, see appropriate «TROUBLE CODE IDENTIFICATION»(ref-21372-S13888618922001010300000) table under TROUBLE CODE IDENTIFICATION.
2. When certain malfunctions or trouble codes initially occur, they will be temporarily stored in ECM memory, but MIL on instrument panel will not come on.
3. The second time malfunction or trouble code is detected, MIL on instrument panel will then come on, provided ignition is turned off and then back on after malfunction or trouble code was first detected. This is referred to as the Two Trip Detection Logic and only applies to specified trouble codes. See «TWO TRIP DETECTION LOGIC TROUBLE CODES»(ref-21372-S36842848062001010300000) table. NOTE: When road testing vehicle in Test Mode, the Two Trip Detection Logic will not function. In Test Mode, the MIL on instrument panel will come on the first time malfunction or trouble code is detected. TWO TRIP DETECTION LOGIC TROUBLE CODES Application (1) Trouble Code Celica 21, 25, 26, 27 & 71 (1) Trouble codes may not apply to all models, as some trouble codes are used only on Calif. models.
4. In Normal Mode, MIL on instrument panel will go off after malfunction is repaired, but trouble codes, except ECM non-memory trouble codes, will be retained in ECM memory until cleared. ECM non-memory trouble codes are not stored in ECM memory. See «ECM NON-MEMORY TROUBLE CODES»(ref-21372-S39798873402001010300000) table.
5. In Test Mode (if equipped), all trouble codes except ECM non-memory trouble codes are retained in ECM memory, even with ignition off and repairs made, until cleared. ECM non-memory trouble codes are not retained in ECM memory. See «ECM NON-MEMORY TROUBLE CODES»(ref-21372-S39798873402001010300000) table.

Note. When in Test Mode, if vehicle is not driven at a speed greater than 6 MPH, ECM will set Trouble Codes 42 and 43. For MIL operation in relation to trouble code when in Test Mode, see appropriate TROUBLE CODE IDENTIFICATION table under TROUBLE CODE IDENTIFICATION .

ECM NON-MEMORY TROUBLE CODES

CLEARING TROUBLE CODES

1. After performing repairs, clear ECM memory of all stored trouble codes. To clear memory, turn ignition off. Remove proper fuse from fuse/relay box for approximately 30 seconds or more. See «FUSE APPLICATION»(ref-21372-S13158820532001010300000) table and «FUSE/RELAY BOX LOCATION»(ref-21372-S00723719822001010300000) table.
2. Depending on ambient temperature, fuse may need to be removed for more than 30 seconds, especially in colder temperatures. Install fuse. Road test vehicle. Ensure system operates properly (with no trouble codes) and MIL flashes continuously and evenly. (Scheme 121) NOTE: Trouble codes may also be cleared by disconnecting negative battery cable. However, other memory functions (clock, radio, alarm, seats, etc.) will be cancelled and must be reset.
3. With certain trouble codes, once trouble code has been cleared from ECM memory, a trouble code detection driving pattern test can be performed to verify repairs and that trouble has not reset. For information on trouble code detection driving pattern test, see «TROUBLE CODE DETECTION DRIVING PATTERN TESTS»(ref-21372-S28022399112001010300000).

FUSE APPLICATION

FUSE/RELAY BOX LOCATION

TROUBLE CODE DETECTION DRIVING PATTERN TESTS

Note. Trouble code driving pattern test may be referred to as driving pattern test.

1. With certain trouble codes, once trouble code has been cleared from ECM memory, a trouble code detection driving pattern test can be performed to verify repairs and that trouble has not reset. Trouble code driving pattern test will duplicate conditions required to set specified trouble codes.
2. Trouble code detection driving pattern test lists procedure to be performed to ensure trouble code has not reset. (Scheme 122)
3. Trouble code detection driving pattern tests apply only to specified trouble codes. See «TROUBLE CODE DETECTION DRIVING PATTERN TEST APPLICATION»(ref-21372-S42432919952001010300000) table. Trouble code detection driving pattern test will be included with proper trouble code chart under TROUBLE CODE CHARTS.

TROUBLE CODE DETECTION DRIVING PATTERN TEST APPLICATION

Scheme 122

TROUBLE CODE DIAGNOSTIC HINTS

Note. To determine a common cause for a trouble code to be set, see TROUBLE CODE DIAGNOSTIC HINTS table.

TROUBLE CODE DIAGNOSTIC HINTS (1)

DIAGNOSTIC CIRCUIT CHECK ("TE1" & "TE2" TERMINAL CIRCUIT)

Terminals "TE1" and "TE2" are located in Data Link Connectors (DLC) No. 1. DLC is located in engine compartment. When these terminals are connected/jumpered with the DLC "E1" terminal, Diagnostic Trouble Codes (DTC) can be accessed in the normal or test modes using the Malfunction Indicator Light (MIL) located in the instrument cluster.

Check for an open or short in wiring harness or for faulty ECM if test mode or output is not activated when DLC terminals "TE1" and "TE2" is jumpered to DLC terminal "E1" or when MIL blinks even though these terminals are not connected or jumpered.

Scheme 123

Scheme 124

DTC 12 - RPM SIGNAL (EXCEPT CALIF.)

The distributor assembly contains 3 pick-up coils. The "G" signal informs ECM of the standard crankshaft position. The "NE" signal informs ECM of the crankshaft position and engine speed.

If "NE" signal is not present to ECM within 2 seconds or more with engine cranking, check for open or short in the "G" or "NE" circuit, or for faulty distributor.

If "G" signal is not present from ECM for 3 seconds or more with engine speed of 600-4000 RPM, check for open or short in "STA" circuit or for a faulty ECM.

Scheme 125

Scheme 126

Scheme 127

DTC 12 - RPM SIGNAL (CALIF.)

The distributor assembly contains 3 pick-up coils. The "G1" and "G2" signals inform ECM of the standard crankshaft position. The "NE" signal informs ECM of the crankshaft position and engine speed.

If "G1", "G2" or "NE" signal is not present to ECM within 2 seconds or more with engine cranking, check for open or short in the "G" or "NE" circuit, or for faulty distributor.

If "G" signal is not present to ECM for 3 seconds or more with engine speed between 600-4000 RPM, check for open or short in "STA" circuit or for a faulty ECM.

Scheme 128

Scheme 129

Scheme 130

DTC 13 - RPM SIGNAL

This code indicates that a momentary interruption of the "G" and "NE" signal from the distributor to ECM has occurred, but has returned to normal. This malfunction is usually a loose or dirty connector or terminal. For further diagnosis, refer to appropriate DTC 12 chart.

DTC 14 - IGNITION SIGNAL

ECM determines ignition timing. ECM turns on "Tr1" circuit at a predetermined angle before desired ignition timing, and outputs an ignition signal to the Integrated Ignition Assembly (IIA). Since the width of the "IGT" signal is constant, dwell angle control circuit in the IIA determines the time control circuit starts primary current flow to ignition coil, based on engine RPM and ignition timing one revolution ago, that is, the time "Tr2" circuit turns on.

When it reaches the ignition timing, ECM turns off "Tr1" and outputs the "IGT" signal "0". This turns off "Tr2", interrupting the primary current flow and generating a high voltage in the secondary coil, firing the spark plugs. Also, by the counter electromotive force generated when the primary current is interrupted, the ignitor sends an ignition confirmation signal (IGF) to the ECM. The ECM stops fuel injection as a fail safe function when "IGF" signal is not input to ECM.

If "IGF" signal to ECM is not present after 4 consecutive "IGT" signals, check for open or short in "IGF" or "IGT" circuit from distributor to ECM. Check for faulty ignitor or ECM.

Scheme 131

Scheme 132

Scheme 133

Scheme 134

Scheme 135

Scheme 136

DTC 16 - ECT CONTROL SIGNAL

Signal from automatic transmission CPU retards engine ignition timing during shifting, thus momentarily reducing engine torque output for smooth clutch operation and reduce shift roughness.

If there is a fault in communications between ECM and A/T CPU, check for faulty ECM. Fault will set DTC 16 and prohibits transmission torque control.

Scheme 137

DTC 21 - OXYGEN SENSOR SIGNAL

This code sets when the main oxygen sensor signal voltage is reduced between .35-.70 volt for 60 seconds under the following conditions

1. Engine coolant temperature at 176°F (80°C) or greater.
2. Engine speed at 1500 RPM or greater.
3. Engine load.
4. Main oxygen sensor signal voltage alternating at greater than or less than .45 volt.

Scheme 138

Scheme 139

Scheme 140

Scheme 141

DTC 22 - ENGINE COOLANT TEMPERATURE SENSOR SIGNAL

The engine coolant temperature sensor is a thermistor that changes its resistance value according to engine coolant temperature. ECM supplies a 5-volt reference voltage to engine coolant temperature through ECM terminal "E6". When sensor resistance changes, ECM changes fuel injection volume to improve driveability during cold engine operation.

A failure code is set when there is an open or short in engine coolant temperature sensor circuit for .5 second or more. Check for open or short in engine coolant temperature sensor circuit, a faulty sensor or ECM.

Scheme 142

Scheme 143

Scheme 144

DTC 24 - INTAKE AIR TEMPERATURE SENSOR SIGNAL

Intake Air Temperature (IAT) sensor is built into air cleaner cover. The IAT sensor senses the intake air temperature. If ECM detects a problem in this circuit, it operates in the fail safe mode in which the intake air temperature is assumed to be 68°F (20°C).

A failure code is set there is an open or short in IAT sensor circuit for .5 second or more. Check for open or short in IAT circuit, a faulty IAT sensor or ECM.

Scheme 145

Scheme 146

DTC 25 is set under following conditions

* Main oxygen sensor voltage is .45 volt or less (lean) for 90 seconds when engine coolant temperature is at 140°F (60°C) or greater, and engine speed at 1500 RPM or greater.

* Engine speed varies by greater than 15 RPM over the preceding crank position period during a period of 30 seconds or more with engine idling and engine coolant temperature at 140°F (60°C) or greater.

DTC 26 is set under following conditions

1. Engine speed varies by greater than 15 RPM over the preceding crank position during a period of 50 seconds or more with engine idling and engine coolant temperature at 140°F (60°C) or greater.

Scheme 147

Scheme 148

Scheme 149

Scheme 150

Scheme 151

DTC 27 - SUB-OXYGEN SENSOR SIGNAL (CALIF.)

DTC 27 is set when the main oxygen sensor signal is .45 volt or greater and sub-oxygen sensor signal is .45 volt or less when engine coolant temperature is at 176°F (80°C) or greater and engine speed at 1500 RPM or greater with accelerator pedal fully depressed for more than 2 seconds.

Check for open or shorted circuit in sub-oxygen sensor circuit, a faulty sub-oxygen sensor or ECM.

Scheme 152

Scheme 153

Scheme 154

DTC 31 - MAP SENSOR SIGNAL

MAP sensor detects the intake manifold absolute pressure as a voltage. ECM determines basic injection duration and basic ignition advance angle based on this voltage. DTC 31 sets when there is an open or short in MAP sensor circuit for .5 second or more. Check for an open or shorted MAP sensor circuit, a faulty MAP sensor or ECM.

Scheme 155

Scheme 156

Scheme 157

DTC 41 - THROTTLE POSITION SENSOR SIGNAL

DTC 41 is set when there is an open or short in throttle position sensor circuit for .5 second or greater. Code will not set when throttle position connector is disconnected. Check for open or short in throttle position sensor circuit, a faulty throttle position sensor or ECM.

Scheme 158

Scheme 159

Scheme 160

DTC 42 - VEHICLE SPEED SENSOR SIGNAL

The No. 1 vehicle speed sensor outputs a 4-pulse signal for every revolution of the rotor shaft, which is rotated by transmission output shaft. ECM determines vehicle speed based on the frequency of these pulse signals.

DTC 42 is set when following conditions are detected continuously for 8 seconds or more

1. On vehicles equipped with A/T, No. 1 vehicle speed signal reads zero MPH with engine speed at 3000 RPM or greater and with P/N switch off.
2. On vehicles equipped with M/T, No. 1 vehicle speed signal reads zero MPH with engine speed at 3000-5000 RPM, engine coolant temperature at 176°F (80°C) or greater and with drive wheels turning (driving load).

Check for open or short in No. 1 vehicle speed sensor circuit, a faulty No. 1 vehicle speed sensor, a faulty combination meter or ECM.

Scheme 161

Scheme 162

Scheme 163

DTC 43 - STARTER SIGNAL

While engine is being cranked, battery voltage is applied to ECM terminal "E5" (STA). Starter signal is mainly used to increase fuel injection volume for the starting injection control and after-start injection control.

DTC 43 is set when there is no starter signal to ECM. Check for open or short in starter signal circuit, an open or short in ignition switch or starter relay circuit or a faulty ECM.

Scheme 164

Scheme 165

DTC 51 - SWITCH CONDITION SIGNAL

ECM uses Park/Neutral (P/N) position switch signal to determine whether transmission is in Park or Neutral, or in some other gear.

ECM uses the output from A/C switch to determine whether or not A/C is operating, so that it can increase idle speed if necessary.

ECM detects idle condition through "IDL" terminal of throttle position sensor.

DTC 51 is set when throttle position switch is off for 3 seconds or more after engine starts. P/N position switch is off with shift position in either Reverse, Drive or Low (A/T). A/C switch on. Check throttle position sensor "IDL" circuit, accelerator pedal and cable adjustment, P/N position switch circuit, A/C switch circuit or for faulty ECM.

Scheme 166

Scheme 167

Scheme 168

DTC 52 - KNOCK SENSOR SIGNAL

DTC 52 is set when ECM detects an open or short in the knock sensor circuit with engine speed of 1200-6000 RPM. Check for open or short in knock sensor circuit, a loose or faulty knock sensor or faulty ECM.

Scheme 169

Scheme 170

Scheme 171

Scheme 172

Scheme 173

DTC 71 - EGR SYSTEM MALFUNCTION

DTC 71 is set when EGR temperature is 140°F (60°C) or less for 50 seconds under the following conditions

1. Engine coolant temperature at 140°F (80°C) or greater.
2. EGR operation possible. Except A/T in 3rd gear or M/T in 5th gear, cruising at 55-60 MPH on a flat road.

Check for open in EGR temperature sensor circuit, a shorted EGR VSV circuit, a plugged EGR passage or a faulty ECM.

Scheme 174

Scheme 175

Scheme 176

Scheme 177

Scheme 178