Engine Controls - Tests W/codes - Turbo: Diagnosis

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

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.
Check bulb circuit on instrument panel and wiring circuit between MIL and ECM. See appropriate wiring diagram information in the «WIRING DIAGRAMS»(ref-21402) article. See «ECM LOCATION»(ref-21404-S25332328302001010300000).
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.
Install Jumper Wire (SST 09843-18020) between terminals TE2 and E1 in Data Link Connector (DLC) with ignition off. (Scheme 126) NOTE: DLC No. 2 is used. (Scheme 126)
Turn ignition on with engine off. Test Mode is operational if MIL on instrument panel flashes.
If MIL fails to flash, check TE2 wiring circuit. See appropriate TE1 & TE2 DIAGNOSTIC CIRCUIT CHECK chart under «TROUBLE CODE CHARTS»(ref-21404-S29532316702001010300000). See «ECM LOCATION»(ref-21404-S25332328302001010300000).
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.
Stop vehicle, but DO NOT turn engine off. Install jumper wire between terminals TE1 and E1 in DLC. (Scheme 126) 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 127)
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 127)
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: 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.
After trouble code(s) is retrieved, remove jumper wires to exit Test Mode. See «NOTES ON TROUBLE CODES»(ref-21404-S14355977512001010300000). For additional information on trouble codes, see «TROUBLE CODE DIAGNOSTIC HINTS»(ref-21404-S41403015982001010300000) table under SELF-DIAGNOSTIC SYSTEM and appropriate «TROUBLE CODE IDENTIFICATION»(ref-21404-S05561050302001010300000) 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 126

Scheme 127

NOTES ON TROUBLE CODES

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-21404-S05561050302001010300000) table under TROUBLE CODE IDENTIFICATION.
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.
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-21404-S01059323462001010300000) 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 (2) Application (1) Trouble Code Turbo 21, 25, 26, 27, 71 & 78 (1) Trouble codes may not apply to all models, as some trouble codes are used only on Calif. models. (2) Two Trip Detection Logic is used on Trouble Code 21 on all except Calif. models.
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-21404-S40134522482001010300000) table.
In Test Mode, 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-21404-S40134522482001010300000) 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.

Application	Trouble Code
Normal Mode	16, 43, 51 & 53
Test Mode	43 & 51

ECM NON-MEMORY TROUBLE CODES

CLEARING TROUBLE CODES

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-21404-S12823381612001010300000) table and «FUSE/RELAY BOX LOCATION»(ref-21404-S02674840952001010300000) table.
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 127) NOTE: Trouble codes may also be cleared by disconnecting negative battery cable. However, other memory functions (clock, radio, alarm, seats, etc.) will be canceled and must be reset.
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-21404-S30339146602001010300000).

Model	Fuse (Amps)
Supra	EFI No. 1 (30)

FUSE APPLICATION

Application	Location
Supra	Driver Side, Front Corner Of Engine Bay

FUSE/RELAY BOX LOCATION

TROUBLE CODE DETECTION DRIVING PATTERN TESTS

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

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.
Trouble code detection driving pattern test lists procedure to be performed to ensure trouble code has not reset. (Scheme 128)
Trouble code detection driving pattern tests apply only to specified trouble codes. See «TROUBLE CODE DETECTION DRIVING PATTERN TEST APPLICATION»(ref-21404-S42768359512001010300000) table. Trouble code detection driving pattern test will be included with proper trouble code chart under «TROUBLE CODE CHARTS»(ref-21404-S29532316702001010300000).

Model	(1) Trouble Code
Turbo	21, 25, 26, 27, 52, 53, 55 & 71
(1) Trouble codes listed may not apply to all models, as some trouble codes are used only on Calif. models.

(1)	Trouble codes listed may not apply to all models, as some trouble codes are used only on Calif. models.

TROUBLE CODE DETECTION DRIVING PATTERN TEST APPLICATION

Scheme 128

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	(1) Diagnostic Hints
12	No "G", "G1", "G2" or "NE" Ignition Signal To ECM Within 2 Seconds After Engine Is Cranked, No "G" Ignition Signal To ECM For 3 Seconds With Engine Speed Of 600-4000 RPM Open In "G-" Circuit
13	No "NE" Ignition Signal To ECM When Engine Speed Is Greater Than Approximately 1000 RPM, No "G" Ignition Signal To ECM When "NE" Signal Is Input 4 Times With Engine Speed Of 600-4000 RPM
14	No "IG" Or "IGF" Ignition Signal To ECM From Ignitor Several Times In Succession
16	Fault In Transmission/Transaxle ECU Or ECM
21	Defective O2 Sensor, Open Or Short Circuit In O2 Sensor Signal
22	Open Or Short Circuit In Engine Coolant Temp. Sensor Signal
24	Open Or Short Circuit In Intake Air Temp. Sensor Signal
25	Lean Signal Sent By O2 Sensor For Several Seconds
26	Rich Signal Sent By O2 Sensor For Several Seconds
27	Open Or Short Circuit In Sub-O2 Sensor Signal
28	Defective O2 Sensor, Open Or Short Circuit In O2 Sensor Signal
31	Open Or Short Circuit In Airflow Meter Or MAP Sensor Signal
32	Open Or Short Circuit Between Airflow Meter Terminals
34	Turbocharger Pressure Is Abnormal
35	Open Or Short Circuit In Turbocharging Pressure Sensor, MAP Sensor Or BARO Sensor
41	Open Or Short Circuit In Throttle Position Sensor Signal
42	No Signal From Vehicle Speed Sensor For Several Seconds
43	No "STA" Signal To ECM Until Engine Reaches 800 RPM With Engine Cranking
47	Open Or Short Circuit In Sub-Throttle Position Sensor Signal
51	(2) Problem In One Of 3 Circuits Monitored By ECM
52	Open Or Short Circuit In Knock Sensor Signal
53	Knock Control In ECM Is Faulty
55	Open Or Short Circuit In Knock Sensor Signal
71	EGR Gas Temp. Less Than Predetermined Level During EGR Control
78	Open Or Short Circuit In Fuel Pump Control Circuit Or Fuel Pump Electronic Control Unit (ECU)
81	Open In ECT1 Circuit Between ECM & Trans. Control Module (TCM) For At Least 2 Seconds
83	Open In ESA1 Circuit Between ECM & Trans. Control Module (TCM) For 1/2 Second After Engine Idles At Least 1/2 Second
84	Open In ESA2 Circuit Between ECM & Trans. Control Module (TCM) For 1/2 Second After Engine Idles At Least 1/2 Second
85	Open In ESA3 Circuit Between ECM & Trans. Control Module (TCM) For 1/2 Second After Engine Idles At Least 1/2 Second
(1) Listed are possible areas causing trouble codes. Not all trouble codes are used on all models. (2) Throttle position sensor, Park/Neutral switch and A/C Signal circuits are monitored.

(1)	Listed are possible areas causing trouble codes. Not all trouble codes are used on all models.

(2)	Throttle position sensor, Park/Neutral switch and A/C Signal circuits are monitored.

TROUBLE CODE DIAGNOSTIC HINTS

DTC 13 - RPM SIGNAL

DTC No.	Detecting Condition(s)	Trouble Area
13	No "NE" Signal to ECM for 0.1 second or more at 1000 RPM or more	Open or short in crank- shaft position sensor circuit, Crankshaft position sensor, ECM
"NE" signal does not pulse 12 times to ECM during the interval between G1 and G2 pulses		Open or short in crank- shaft position sensor circuit, Mechanical malfunction (skipping teeth of timing belt, belt stretched) Crankshaft position sensor, ECM
Deviation in G (G1, G2) and "NE" signal continues for 3 seconds during idling (throttle fully closed) after engine warmed up		Mechanical malfunction (skipping teeth of timing belt, belt streched) Camshaft position sensor No. 1 or No. 2, ECM

DTC 13 - RPM SIGNAL TROUBLE SHOOTING

Scheme 129

Scheme 130

Scheme 130: DTC 14 - IGNITION SIGNAL

Scheme 131

Scheme 132

Scheme 133

DTC 16 - ELECTRONIC-CONTROLLED A/T SIGNAL

The signal from A/T CPU retards the ignition timing of the engine during A/T gear shifting, thus momentarily reducing torque output of the engine for smooth clutch operation inside the transmission and reduced shift shock.