How to read codes from the 1st gen self-diagnostic system (1989-1992)
All mx6's/probes have a self-diagnostic system that monitors the engine sensors for malfunctions. The 2.2L engine uses the Electronic Engine Control system (EEC) and the 3.0L engine uses the Electronic Engine Control-IV system (EEC-IV). The Check Engine Light (CEL) is an amber light that illuminates in the dash panel (gauge pod) when the Electronic Engine Control system senses a malfunction in one of the sensors. This information is stored in the ECA as a two or three digit code. These codes can be read easily by anyone.
What you will need: Piece of wire that is stripped on both ends.
Instructions for the 2.2L engine:
-Make sure the engine is off and the key is out of the ignition.
-Locate the loose single wire harness near the driver's side strut tower. The wire should be red. This connector is called the self-test input connector (STI).
-Use the piece of wire to connect this STI connector to ground (negative battery terminal works well).
-Turn the key to the "ON" position, but do not start the engine.
-Codes are displayed as flashes of the CEL with pauses between digits. If the code has two digits the flashes for the first digit are slightly longer than for the second digit. If there are multiple codes in the ECA, they are separated by a slightly longer pause. Codes are displayed from lowest number to highest, then repeated.
-After repairing a malfunctioning sensor, you need to clear the ECA's memory. Do this by disconnecting the negative battery cable and holding down the brake pedal for at least five seconds.
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THE CODES
1988-1989 ALL (Probe 1989 only)
Code Sensor or Description
01 Ignition Pulse
02 Crankshaft Position Sensor (CPS)
03 Cylinder Identification Sensor A
04 Cylinder Identification Sensor B
05 Knock Sensor or Knock Control Unit
08 Vane Airflow Signal (VAFSIG)
09 Engine Coolant Temperature Sensor (ECT)
10 Vane Air Temperature Sensor (VAT)
12 Throttle Position Sensor (TP)
14 Barometric Pressure Sensor (BP)
15 EGO Sensor (EGO)
16 EGR Valve Position Sensor (EVP)
25 Pressure Regulator Control
26 Canister Purge Solenoid (CANP)
28 EGR Control Solenoid Valve (EGRC)
29 EGR Vent Solenoid Vavle (EGRV)
34 Idle Speed Control Solenoid Valve (ISC)
42 Turbocharger Boost Control Solenoid Valve (BOOST)
1990-1992 [2.2L Non-Turbo]
Code Sensor or Description
01 Ignition Diagnostic Monitor (IDM)
06 Vehicle Speed Sensor (VSS)
08 Vane Air Flow Signal (VAFSIG)
09 Engine Coolant Temperature Sensor (ECT)
10 Vane Air Temperature Sensor (VAT)
12 Throttle Position Sensor (TP)
14 Barometric Pressure Sensor (BP)
15 Exhaust Gas Oxygen Sensor (EGO)
Lean - Voltage Always Below 0.55V
16 EGR Valve Position Sensor (EVP)
17 Exhaust Gas Oxygen Sensor (EGO)
Rich - Voltage Stays At 0.55V
25 Fuel Pressure Regulator Control Solenoid (PRC)
26 Canister Purge Solenoid Valve (CANP)
28 EGR Control Solenoid Valve (EGRC)
34 Idle Speed Control Solenoid Valve (ISC)
55 Torque Converter Speed Sensor (TCS)
60 Shift Solenoid #1 (SS1)
61 Shift Solenoid #2 (SS2)
62 Shift Solenoid #3 (SS3)
63 Torque Converter Clutch Control Solenoid (CCC)
(I can accept no credit for this post. It was provided by someone else a long time ago on this forum. I posted it here since it is referred to often.)
jSTeele
