Diagnostic Trouble Codes - 1990
Ford
| 11 | System "pass" |
| 12 | Unable to control RPM to Self Test upper limit band. |
| 13 | Unable to control RPM to Self Test lower limit band. |
| 14 | PIP circuit failure. |
| 18 | No tach. |
| 19 | Failure of EEC power supply. |
| 21 | ECT out of range. |
| 22 | MAP out of range. |
| 23 | TPS out of range. |
| 29 | Insufficient input from Vehicle Speed Sensor. |
| 31 | PFE circuit is below minimum. |
| 32 | EGR valve not seated. |
| 33 | EVP not closing properly. |
| 34 | No EGR flow. |
| 35 | PFE circuit is above maximum voltage. |
| 39 | AXOD converter bypass not applying correctly. |
| 41 | HEGO sensor circuit indicates system lean (Right HEGO). |
| 42 | HEGO sensor circuit indicates system rich (Right HEGO). |
| 51 | ECT sensor input too high. |
| 52 | Power steering pressure switch is open. |
| 53 | TPS input too high. |
| 54 | ACT (VAT) input too high. |
| 57 | AXOD Neutral Pressure Switch open. |
| 59 | Transhydraulic switch (THS 3/4) failed in open position. |
| 61 | ECT input too low. |
| 63 | TPS input too low. |
| 64 | ACT (VAT) input too low. |
| 67 | AXOD Neutral Pressure Switch closed. |
| 68 | AXOD Transmission Temperature Switch open. |
| 69 | Transhydraulic switch (THS 3/2) failed. |
| 70 | EEC-IV data transmission circuit failed. |
| 71 | Cluster Control Assembly circuit failed. |
| 72 | Message Center Control Assembly circuit failed. |
| 74 | Brake on/off circuit failed. |
| 79 | A/C on during Self Test. |
| 83 | High speed Electro Drive Fan circuit failure. |
| 84 | EGR Vacuum Regulator circuit failure. |
| 85 | Canister purge (CANP) circuit failure. |
| 87 | Fuel pump primary circuit fault. |
| 88 | Electro Drive Fan circuit failure. |
| 89 | AXOD Lock Up Solenoid circuit failure. |
| 91 | HEGO sensor circuit indicates system lean (Left HEGO). |
| 92 | HEGO sensor circuit indicates system Rich (Left HEGO). |
| 95 | Fuel pump secondary circuit failure. |
| 96 | Fuel pump secondary circuit failure. |
** On 1986 and later vehicles, this represents RPM too high/low or throttle pedal was depressed during KOER Self-Test
*** Low flow of unmetered air on 1987-88 1.9L EFI engine
To extract DTCs from the computer for diagnostic purposes, the Self Test connector is used.
- Start engine and bring to normal operating temperature. If engine will not start or stalls after starting, proceed with next step.
- Turn the key "OFF", then wait ten seconds.
- Activate the self test by grounding the Self-Test Input (STI) connector.
- Turn the ignition key "ON".
- Record all codes received.
- Turn ignition "OFF".
Data Link Connector (DLC)
(Located Underhood)
Analog Voltmeter Connection
