Service Codes: 1988 Ford EEC-IV: Codes

11 - System "Passes" test procedure.
12 - Idle RPM not within specifications.
13 - Idle Speed Control (ISC) RPM too high.
14 - Erratic ignition signal from PIP.
15 - Power interruption to Keep Alive Memory (KAM), Pin No. 1.
16 - Idle Speed Control (ISC) RPM too high or throttle pedal touched during KOER SELF-TEST.
17 - Idle Speed Control (ISC) RPM too low.
18 - Spark timing incorrect.
19 - Idle Speed Control (ISC) RPM too low,
21 - Engine Coolant Temperature (ECT) sensor/signal out of range.
22 - Manifold Absolute Pressure (MAP) sensor/signal out of range.
23 - Throttle Position Sensor (TPS) signal/out of range.
24 - Air Charge Temperature (ACT) sensor/signal out of range.
25 - Knock sensor signal not received by ECA.
27 - Vehicle Speed Sensor (VSS) signal not received (2.3L Turbo MPFI).
28 - Ambient temperature less than 50°F (10°C).
29 - Vehicle Speed Sensor (VSS) not functioning.
31 - Pressure Feedback EGR (PFE) circuit open.
32 - EGR Control solenoid (EGRC) or EGR Vent solenoid (EGRV) signal failure.
33 - EGR valve not operating or sticking.
34 - EGR Control solenoid (EGRC) or EGR Vent solenoid (EGRV) signal failure.
35 - RPM too low for EGR testing or Pressure Feedback EGR (PFE) circuit short.
39 - Converter by-pass clutch not operating correctly.
41 - Heated Exhaust Gas Oxygen (HEGO) sensor, lean signal in closed loop.
42 - Heated Exhaust Gas Oxygen (HEGO) sensor signal rich in closed loop. Excessive fuel pressure or volume.
43 - Heated Exhaust Gas Oxygen (HEGO) sensor signal lean during WOT test.
47 - Idle speed control (by-pass Air), low flow of unmetered air.
48 - Idle speed control (by-pass Air), high flow of unmetered air.
51 - Engine Coolant Temperature (ECT) sensor, signal circuit open.
52 - Power Steering Pressure Switch (PSPS) signal open or shorted, steering wheel not turned during KOER SELF-TEST.
53 - Throttle Position Sensor (TPS) signal circuit short.
54 - Air Charge Temperature (ACT) sensor circuit open.
55 - Key power check circuit open (CFI engines).
56 - Vane Airflow (VAF) sensor, shorted VREF to SIG circuit.
57 - Neutral Pressure Switch (NPS) failed in neutral.
58 - Vane Air Temperature (VAT) sensor circuit open.
59 - Transmission Hydraulic Switch (THS), 4/3 pressure switch, failed in open position.
61 - Engine Coolant Temperature (ECT) sensor, signal circuit short.
62 - Transmission Hydraulic Switch (THS) 4/3 pressure switch failed in closed position.
63 - Throttle Position Sensor (TPS) signal circuit open.
64 - Air Charge Temperature (ACT) sensor circuit short.
65 - Did not go to closed loop fuel control on HEGO switching. Faulty HEGO signal.
66 - Vane Airflow (VAF) sensor, shorted SIG to SIG RTN circuit.
67 - Neutral Drive Switch (NDS), A/C input, Neutral Pressure Switch (NPS) signal interrupted.
68 - Vane Air Temperature (VAT) sensor circuit short.
69 - Transmission Hydraulic Switch (THS) 3/2 pressure switch failed in closed position.
72 - Fault in VPWR circuit to EEC power relay.
73 - Throttle Position Sensor (TPS) did not rotate more than 25% during dynamic response test.
74 - Brake On/Off (BOO) switch always open, or not applied during KOER SELF-TEST.
75 - Brake On/Off (BOO) switch always closed, or signal circuit shorted.
76 - Vane Airflow (VAF) sensor, no voltage signal increase during Dynamic Response Test.
77 - ECA request for Dynamic Response Test.
78 - Power supply circuit to EEC power relay interrupted.
79 - Neutral Drive Switch (NDS), A/C input, Neutral Position Switch (NPS) signal interrupted.
81 - Open or shorted signal from turbo boost solenoid.
82 - Integrated Controller Relay Module (ICRM), electric fan processor signal shorted to ground or open.
83 - Integrated Controller Relay Module (ICRM), high speed electric fan processor signal shorted to ground or open.
84 - EGR Valve Regulator (EVR) resistance signal out of range.
85 - Fuel mixture made leaner (Adaptive Fuel) to accommodate canister purge function or excessive fuel pressure or volume.
86 - Fuel mixture made richer (Adaptive Fuel) due to low fuel pressure or low volume.
87 - Open in fuel pump circuit or VPWR circuit between EEC power relay and fuel pump relay.
88 - Integrated Controller Relay Module (ICRM), electric fan processor signal shorted to ground or open.
89 - Converter by-pass clutch solenoid always open or closed.
91 - Heated Exhaust Gas Oxygen (HEGO) sensor, lean signal in closed loop.
92 - Heated Exhaust Gas Oxygen (HEGO) sensor signal rich in closed loop. Excessive fuel pressure or volume.
95 - Inertia switch or fuel pump circuit shorted or open.
96 - No power to fuel pump relay.
98 - Vehicle did not pass KOEO SELF-TEST. Code 11 necessary to proceed with KOER test.
99 - ECA has not stored enough information to control idle speed.

DIAGNOSIS BY SYMPTOM (SYMPTOM-TO-DIAGNOSTIC TEST)

Symptom		Go To Test: (Step No.)
Rough/Miss/Stall/Lacks Power/Rough Idle/Surge in Self Test		D20 (1)
Stalls When Parking
2.3L EFI OHC		B15 (3)
2.3L EFI TC		N/A
2.3L EFI HSC		N/A
Surges With A/C On At Idle
2.3L EFI OHC		D7 (17)
2.3L EFI TC		N/A
2.3L EFI HSC		D7 (17)
A/C Stays On During WOT
2.3L EFI OHC		D7 (8)
2.3L EFI TC		D22 (41)
2.3L EFI HSC		D7 (8)
A/C Not Functioning
2.3L EFI OHC		D7 (1)
2.3L EFI TC		D22 (39)
2.3L EFI HSC		D7 (1)
A/C Compressor Always Runs
2.3L EFI OHC		D7 (19)
2.3L EFI TC		N/A
2.3L EFI HSC		N/A
High Idle After Restart. May Knock 3-5 Minutes After Restart
2.3L EFI OHC		N/A
2.3L EFI TC		B7 (1)
2.3L EFI HSC		N/A
Low Idle With A/C On		B13 (10)
High Idle In "Drive", A/T Trans Only.		N/A
Shift Indicator Light Always/Never On
2.3L EFI OHC		N/A
2.3L EFI TC		N/A
2.3L EFI HSC		D6 (1)
"CHECK ENGINE" Light Always On		D11 (1)
"CHECK ENGINE" Light Never On		D11 (2)
"CHECK ENGINE"/"CHECK DCL" Message On		N/A
Stumble After Hot Restart		C1 (20)
Engine Will Not Restart		N/A
Fuel Pump Runs With Engine Off
2.3L EFI OHC		C2 (13)
2.3L EFI TC		D22 (14)
2.3L EFI HSC		N/A
Gasoline Fumes In Engine Compartment
2.3L EFI OHC		N/A
2.3L EFI TC		N/A
2.3L EFI HSC		D4 (1)
Detonation/Spark Knock
2.3L EFI OHC		B7 (1)
2.3L EFI TC		B7 (2)
2.3L EFI HSC		N/A
Low Power, No Turbo Boost
2.3L EFI OHC		N/A
2.3L EFI TC		D8 (1)
2.3L EFI HSC		N/A
Low Turbo Boost Pressure
2.3L EFI OHC		N/A
2.3L EFI TC		D8 (9)
2.3L EFI HSC		N/A
Engine Cooling Fan(s) Inoperative		N/A
Cooling Fan(s) Always On		N/A
Low Turbo Boost Pressure
2.3L EFI OHC		N/A
2.3L EFI TC		D8 (9)
2.3L EFI HSC		N/A
Engine Cooling Fan(s) Inoperative		N/A
Cooling Fan(s) Always On		N/A
Engine "Lugs" or "Bucks"		N/A

KEY ON ENGINE OFF (KOEO) CODE-TO-CIRCUIT TEST MENU

Code No.		Go To: Circuit Test No. (Step No.)
15		D15 (3)
19		D17 (1)
21		B5 (1)
22		B6 (1)
23		B8 (1)
24		B2 (1)
28 (Turbo MPFI Only)		B1 (1)
31
(OHC MPFI)		B4 (2)
(HSC MPFI)		B10 (1)
34 (HSC MPFI)		B10 (8)
35 (HSC MPFI)		B10 (5)
51		B5 (4)
52 (Except Turbo MPFI)		B15 (1)
53		B8 (3)
54		B2 (10)
56 (Turbo MPFI)		B9 (10)
58		B1 (10)
61		B5 (6)
63		B8 (6)
64		B2 (7)
66 (Turbo MPFI)		B9 (6)
67		B13 (1)
68 (Turbo MPFI)		B1 (6)
81		D8 (1)
82		D22 (58)
83
(OHC MPFI)		B4 (14)
(Turbo MPFI)		D22 (25)
84
(OHC MPFI)		B10 (11)
(Turbo MPFI)		B4 (14)
(HSC MPFI)		B10 (11)
85
(Turbo MPFI)		D9 (6)
(HSC MPFI)		D4 (6)
87
(OHC MPFI)		C2 (7)
(Turbo MPFI)		D22 (15)
(HSC MPFI)		C2 (7)
88 (Turbo MPFI)		D9 (1)
89 (OHC MPFI)		D9 (1)
93 (HSC MPFI)		D2 (11)
95 (HSC MPFI)		C2 (11)
96 (HSC MPFI)		C2 (17)

KEY ON ENGINE RUNNING (KOER) CODE-TO-CIRCUIT TEST MENU

Code No.

Go To: Circuit Test No. (Step No.)

D5 (1)

(OHC MPFI)

D2 (15)

(Turbo MPFI)

D2 (11)

(HSC MPFI)

D2 (11)

16 (OHC MPFI)

D5 (1)

B5 (1)

(OHC MPFI)

B6 (7)

(Turbo MPFI)

B6 (1)

(HSC MPFI)

B6 (7)

B8 (1)

B2 (1)

28 (Turbo MPFI Only)

B1 (1)

(OHC MPFI)

B4 (1)

(HSC MPFI)

B10 (16)

(OHC MPFI)

B4 (8)

(HSC MPFI)

B10 (20)

(OHC MPFI)

B4 (19)

(Turbo MPFI)

D1 (1)

(HSC MPFI)

B10 (19)

(OHC MPFI)

B4 (19)

(HSC MPFI)

B10 (19)

C1 (11)

C1 (23)

52 (HSC MPFI)

B15 (5)

72 (Except Turbo MPFI)

B6 (10)

B8 (10)

74 (Except HSC MPFI)

B14 (1)

75 (Except HSC MPFI)

B14 (5)

D10 (1)

⁽¹⁾ *

⁽¹⁾	If Code 98 is displayed, perform KEY ON/ENGINE OFF (KOEO) SELF-TEST and obtain a Code 11 for KOEO QUICK TEST.

CONTINUOUS SELF-TEST - CODE-TO-CIRCUIT TEST MENU

Code No.		Go To: Circuit Test No. (Step No.)
14		D23 (1)
15		D15 (1)
18		D12 (1)
22		B6 (15)
41
(Turbo MPFI)		C1 (30)
(All Others)		C1 (29)
42 (Turbo MPFI Only)		C1 (30)
43 (Turbo MPFI Only)		C1 (30)
51		B5 (10)
53		B8 (11)
56 (Turbo MPFI Only)		B9 (12)
61		B5 (13)
63		B8 (15)
65 (Turbo MPFI Only)		C1 (30)
66 (Turbo MPFI Only)		B9 (15)
67 (Turbo MPFI Only)		B13 (1)
68 (Turbo MPFI Only)		B1 (12)
72 (Turbo MPFI Only)		D18 (12)
87 (HSC MPFI Only)		C2 (24)
95 (HSC MPFI Only)		C2 (20)
96 (HSC MPFI Only)		C2 (22)