Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1990 Ford Bronco II 4WD, Standard, M5OD-R1FACTORY OEM SERVICE PROCEDURE
2.3L VIN [A]
CODE DEFINITION
| Code | Condition (1) | Definition | ||
|---|---|---|---|---|
| 11 | orc | System pass | ||
| 12 | r | Cannot control RPM during Self-Test high RPM check | ||
| 13 | r | Cannot control RPM during Self-Test low RPM check | ||
| 14 | c | PIP circuit failure | ||
| 15 | o | ECA Read Only Memory (ROM) test failed | ||
| 15 | c | ECA Keep Alive Memory (KAM) test failed | ||
| 18 | r | SPOUT circuit open | ||
| 18 | c | Erratic IDM input to processor | ||
| 19 | o | Failure in ECA internal voltage | ||
| 21 | or | Engine Coolant Temp (ECT) out of Self-Test range | ||
| 22 | orc | Manifold Absolute Pressure (MAP) out of Self-Test range | ||
| 23 | or | Throttle Position (TP) out of Self-Test range | ||
| 24 | or | Air Charge Temp (ACT) out of Self-Test range | ||
| 28 | c | Loss of IDM - right side | ||
| 29 | c | Insufficient input from Vehicle Speed Sensor (VSS) | ||
| 31 | orc | EVP circuit below minimum voltage | ||
| 32 | orc | EVP voltage below closed limit | ||
| 33 | rc | EGR valve opening not detected | ||
| 34 | orc | EVP voltage above closed limit | ||
| 35 | orc | EVP circuit above maximum voltage | ||
| 41 | r | HEGO sensor circuit indicates system lean | ||
| 41 | c | No HEGO switching detected | ||
| 42 | r | HEGO sensor circuit indicates system rich | ||
| 48 | c | Loss of IDM - left side | ||
| 51 | oc | ECT indicated -40°F/circuit open | ||
| 52 | o | Power Steering Pressure Switch (PSPS) circuit open | ||
| 52 | r | PSPS circuit did not change states | ||
| 53 | oc | TP circuit above maximum voltage | ||
| 54 | oc | ACT indicated -40°F/circuit open | ||
| 61 | oc | ECT indicated 254°F/circuit grounded | ||
| 63 | oc | TP circuit below minimum voltage | ||
| 64 | oc | ACT indicated 254°F/circuit grounded | ||
| 67 | o | Neutral Drive Switch (NDS) circuit open or A/C on | ||
| 72 | r | Insufficient MAP change during Dynamic Response Test | ||
| 73 | r | Insufficient TP change during Dynamic Response Test | ||
| 74 | r | Brake On/Off (BOO) circuit failure or not actuated during Self-Test | ||
| 77 | r | Operator error (Dynamic Response/Cylinder Balance tests) | ||
| 84 | o | EGR Vacuum Regulator (EVR) circuit failure | ||
| 86 | o | Shift Solenoid (SS) circuit failure | ||
| 87 | oc | Primary Fuel Pump circuit failure | ||
| 88 | o | Loss of Dual Plug input control | ||
| 89 | o | Clutch Converter Override (CCO) circuit failure | ||
| 95 | oc | Fuel pump circuit open; ECA to motor ground | ||
| 96 | oc | Fuel pump circuit open; Battery to ECA | ||
| 98 | r | Hard fault is present (currently in FMEM) | ||
| NO CODES | Unable to initiate Self-Test or unable to output Self-Test codes | |||
| CODE NOT LISTED | Service codes displayed are not applicable to vehicle being tested | |||
|
||||
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.