2JZ OBD Engine error checking

The ECU stores an error code so that you can check for problems. Rather than requiring a bug diagnostics machine, you can use a simple paperclip, or a short wire. You use this to bridge the connections E1 and TE1 in the diagnostics port. For VVT-i versions please use Tc and E1 as ODB2 engines (mid 1996+) use Tc and E1 instead.”

For OBD2  codes please use a compatible OBD2 Scanner. The paperclip method won’t work well for those ECU’s when searching for error codes.
Also, Make sure you have de-immobilised your car as some immobilisers stop the engine light from flashing.

Here are the different types of plugs displayed (images taken from other sites/google):

1JZ Supra/Soarer:

OBD1 Round plug:

Soarer plugs:

• Before proceeding, make sure the:
  • CHECK ENGINE light circuit is functional. It should be ON when the ignition switch is ON with the engine stopped.
  • Battery voltage is above 11 volts.
  • Throttle valve is fully closed (Throttle Position Sensor IDL points closed).
  • Accessory switches (A/C, etc.) are OFF.
  • Engine is at normal operating temperature (if possible).
• Turn ignition switch to ON position.
  • Do not start the engine.
  • Place a jumper wire across TEl and El terminals in engine check connector.

• Count number of flashes from CHECK ENGINE light.
  • If system is operating normally (with no detected faults), the CHECK ENGINE light will blink continuouslyand evenly about 2 times a second.
• Otherwise, the light will blink a number of times equal to the trouble code as follows:
  • The light blinks only (.5 second ON, .5 second OFF) when indicating a number.
  • The light will be OFF for 1.5 seconds between the first digit and the second digit of the code.
  • If more than one code is stored, the light will be OFF for 2.5 seconds before the next code is displayed.
  • Once all code(s) have been displayed, the light will be OFF for 4.5 seconds and then the whole sequence will repeat.
• The diagnostic code series will continue to repeat as long as the check connecter terminals TEl and El are connected.
• When finished, remove the jumper wire.
• After repairing the malfunction, clear the codes from the ECUs memory: Remove the EFI fuse (15A) for 30 seconds with the ignition switch OFF.

Most common 2JZ CEL codes chart:

DIAGNOSTIC TROUBLE CODE CHART (2JZ-GTE)
DTC	Circuit	Diag.. Trouble Code Detecting Condition	Trouble Area	Normal  Mode	Test  Mode	Memory
No.
–	Normal	No code is recorded	–	–	–	–
12	G, NE Signal  (No. 1)	No “NE” or “G1” and “G2 signal to ECM for 2 sec. or more after cranking.	Open or short in crankshaft position sensor, camshaft position sensor No. 1, No. 2 circuit.	ON	n/a	Yes
			Crankshaft position sensor
			Camshaft position sensor No. 1, No. 2
			Started
			ECM
13	G, NE Signal  (No. 2)	No NE signal to ECM for 0.1 sec. or more at 1,000 rpm or more.	Open or short in crankshaft position sensor circuit.	ON	n/a	Yes
			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 crankshaft position sensor circuit.	n/a	ON
			Mechanical system malfunction (skipping teeth of timing belt, belt stretched)
			Crankshaft position sensor
			ECM
		Deviation in G (G1, G2) and NE signal continues for 3 sec. during idling (throttle fully closed) after engine warmed up.	Mechanical system malfunction (skipping teeth of timing belt, belt stretched)	ON	n/a
			Camshaft position sensor No. 1, No. 2
			ECM
14	Ignition Signal	No IGF signal to ECM for 4~7 consecutive IGT signals with engine speed less than 3,000 rpm.	Open or short in IGF circuit from igniter to ECM	ON	n/a	Yes
			Igniter
			ECM
16	A/T Control  Signal	Fault in communications between the engine CPU and A/T CPU in the ECM.	ECM	ON	n/a	No

21	Main Heated  Oxygen Sensor  Signal	Open or short in heater circuit of main heated oxygen sensor (Fr) for 0.5 sec. or more.	Open or short in heater circuit of main heated oxygen sensor.	ON	n/a	Yes
			Main heated oxygen sensor heater
			ECM
		Main heated oxygen sensor signal voltage is reduced to between 0.35V and 0.70V for 60 sec. under condition	Main heated oxygen sensor circuit	ON	ON
			Main heated oxygen sensor
		a) ~ (d). (2 trip detection logic)
		a). Engine coolant temp.: Between 80° C (176°F) and 95°C (203°F)
		b). Engine speed: 1,500 rpm or more
		c). Load driving (EX. A/T in overdrive (5th for M/T), A/C ON, Flat road, 50 mph <80 km/h>)
		d). Main heated oxygen sensor signal voltage:  Alternating above and below 0.45 V.
22	Engine Coolant Temp. Sensor Circuit	Open or short in engine coolant temp. sensor circuit for 0.5 sec or more.	Open or short in engine coolant temp. sensor circuit.	ON	ON	Yes
			Engine coolant temp. sensor
			ECM
24	Intake Air Temp. Sensor Signal	Open or short in intake air temp. sensor circuit for 0.5 sec. or more.	Open or short in intake air temp. sensor circuit.	ON	ON	Yes
			Intake air temp. sensor
25	Air-Fuel Ratio Lean Malfunction
26	Air-Fuel Ratio Rich Malfunction
27	Sub Heated Oxygen Sensor Signal
31	Mass Air Flow Meter Circuit
34	Turbo Pressure Malfunction
35	Turbo Pressure Sensor Circuit
35(?)	Barometric  Pressure Sensor Circuit
41	Throttle Position
	Sensor Signal
42	No. 1 Vehicle Speed Sensor Signal (for A/T)
	No. 1 Vehicle Speed Sensor  Signal (for M/T)
43	Starter Signal
47	Sub-Throttle Position Sensor Signal
52	Knock Sensor Signal (front side)
53	Knock Control Signal	Engine control computer (for knock control) malfunction at engine speed between 650 rpm and 5,200 rpm.	ECM	ON	n/a	No
55	Knock Sensor Signal (rear side)
71	EGR System  Malfunction
78	Fuel Pump Control Signal
51	Switch Condition Signal	1. 3 sec. or more after engine starts, with closed throttle position switch OFF (IDL1).	A/C switch circuit.	n/a	OFF	No
		2. Park/neutral position switch: OF (Shift position in “R”, “D”, “2”, or “L” position)	Throttle position sensor IDL circuit.
		3. A/C switch ON.	Park/neutral position switch circuit
			Accelerator pedal and cable.
			ECM

OBD2 Codes:

Trouble code identification
OBD-11 code	Fault location	Probable cause
PO, P2,UO	Refer to OBD-II trouble code tables	–
P1100	Barometric pressure (BARO) sensor – circuit malfunction	ECM
P1120	Accelerator pedal position (APP) sensor – circuit malfunction	Wiring, APP sensor, ECM
P1121	Accelerator pedal position (APP) sensor – range/   performance problem	APP sensor, ECM
P1125	Throttle actuator control (TAC) motor- circuit malfunction	Wiring, TAC motor, ECM
P1126	Magnetic clutch – circuit malfunction	Wiring, magnetic clutch, ECM
P1127	Traction control system – circuit malfunction	Wiring, ECM
P1128	Throttle actuator control (TAC) motor- lock malfunction	TAC motor, throttle body, ECM
P1129	Throttle actuator control (TAC) system -malfunction	Wiring, ECM
P1200	Fuel pump (FP) relay/ECM – circuit malfunction	Wiring, fuel pump/control module, ECM
P1300	Ignition control – circuit malfunction	Wiring, ignition module, ECM
P1335	Crankshaft position (CKP) sensor – no signal	Wiring, CKP sensor, starter motor, ECM
P1349	Camshaft position (CMP) actuator system – malfunction	Valve timing, CMP actuator, ECM
P1400	Throttle position (TP) sensor 2 – circuit malfunction	Wiring, TP sensor, ECM
P1401	Throttle position (TP) sensor 2 – range/   performance problem	TP sensor
P1405	Turbocharger (TC) boost pressure sensor- circuit malfunction	Wiring, TC boost pressure sensor, ECM
P1406	Turbocharger (TC) boost pressure sensor- range/performance problem	TC boost pressure sensor
P1500	Starter signal – circuit malfunction	Wiring, ignition switch, engine control relay, ECM
P1511	Turbocharger (TC) boost pressure- pressure too low	Intake system/air control valve, wiring, TC   wastegate regulating valve/actuator, ECM
P1512	Turbocharger (TC) boost pressure – pressure too high	Wiring, TC wastegate regulating valve/actuator, ECM
P1520	Stop lamp switch – signal malfunction	Wiring, stop lamp switch, ECM
P1565	Cruise control switch – signal malfunction	Wiring, cruise control switch, ECM
P1600	Engine control module (ECM) – supply voltage	Wiring, ECM
P1605	Knock control – malfunction	ECM
P1630	Traction control system – malfunction	Wiring, throttle control module, ECM
P1633	Engine control module (ECM)- throttle actuator control (TAC) system – malfunction	ECM
P1652	Turbocharger (TC) 2 air control solenoid – circuit malfunction	Wiring, air control solenoid, ECM
P1656	Oil control valve – circuit malfunction	Wiring, oil control valve, ECM
P1658	Turbocharger (TC) wastegate regulating valve – circuit malfunction	Wiring, TC wastegate regulating valve, ECM
P1661	Turbocharger (TC) 2 exhaust gas control valve – circuit malfunction	Wiring, exhaust gas control valve, ECM
P1662	Exhaust bypass valve – circuit malfunction	Wiring, exhaust bypass valve, ECM
P1780	Park/neutral position (PNP) switch – circuit malfunction	Wiring, PNP switch, ECM