11 System checks OK
12 Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low)
13 ISC did not respond properly (extends to touch throttle then retracts for KOEO)
Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too high)
ISC sticking, open ITS circuit or TP sticking
14 Ignition pickup was erratic
15 No Keep Alive Memory power to PCM pin 1 or bad PCM (Memory Test Failure)
KAM (pin 1) was interrupted (was battery disconnected ?)
16 1.9L & 2.5L - Throttle stop set too high
2.3L - RPM's too low
Electronic ignition - IDM circuit fault
17 1.9L & 2.5L - Throttle stop set too low
18 Check base timing & advance function
(M) Ignition TACH signal erratic
19 No Vehicle Power (pins 37 + 57) or bad PCM
Erratic idle during test (reset throttle & retest)
Electronic ignition Cylinder ID sensor/circuit problem
21 Engine Coolant Temperature (ECT) sensor out of range
22 MAP (vacuum) or BARO signal out of range
23 Throttle sensor out of range or throttle set too high
24 Intake Air Temperature (IAT) or Vane Air Temperature (VAT) sensor out of range
25 Knock sensor not tested (ignore if not pinging)
26 Mass Air Flow (MAF) or Vane Air Flow (VAF) out of range
Transmission Oil Temperature (TOT) sensor out of range
27 Vehicle Speed Sensor problem
28 Vane Air Temperature (VAT) sensor out of range
2.3L w/Electronic Ignition - Cyl ID, IDM low or right coil pack failure
29 Vehicle Speed Sensor problem
. . . . . . . . . . . . . . . . . . . .
EGR Codes depend on what type of EGR system you have
EVP is for vehicles equipped with EGR solenoid(s), with or without an EVP sensor
EVR is for vehicles equipped with an EGR Vacuum Regulator (EVR) and an EGR Valve Position (EVP) sensor
PFE is for vehicles with Pressure Feedback EGR (PFE) sensor and and an EGR Vacuum Regulator (EVR)
. . . . . . . . . . . . . . . . . . . .
31 EVP - EVP signal is/was out of range
EVR - EVP signal is/was low
PFE - PFE signal is/was low
32 EVP - (R) EGR not responding properly during test
EVR - (O, R, M) EVP signal is/was low
PFE - PFE shows low pressure, EGR not seating or memory, not seating intermittently
33 ALL - EGR did not open/ respond during test or if memory code, did not open intermittently
34 EVP - EGR did not respond properly during test
EVR - EVP sensor is/was high
PFE - PFE sensor is/was out of range
35 EVP - Engine RPM's too low to test EGR system
EVR - EVP sensor signal is/was high
PFE - PFE sensor signal is/was high
38 Idle Tracking Switch signal was intermittent
39 Transmission Torque Converter clutch not engaging
41 System lean
System was lean for 15 seconds or more (no HO2S switching)
42 System rich
System was rich for 15 seconds or more (no HO2S switching)
43 HO2S sensor not reading (run at 2000 rpm's for 2 minutes and retest - check for HO2S switching)
Was lean at WOT for 3 seconds or more
44 AIR system inoperative
45 AIR not Diverting (AIRD)
Electronic Ignition - coil primary circuit failure
46 AIR Bypass (AIRB) not working
Electronic Ignition - primary circuit failure coil 2
47 Low flow unmetered air (check for small vacuum leaks, injector o'rings, gaskets etc.)
48 High flow unmetered air (check for large vacuum leak, inlet hoses etc.)
Electronic Ignition - coil primary circuit failure
49 Electronic Ignition - spout signal circuit problem
Transmission 1/2 shift problem
51 Engine Coolant Temperature (ECT) sensor signal is/was too high
52 Power Steering Pressure Switch/circuit open
Did you turn wheel during test ?
53 Throttle Position sensor too high
54 Intake Air Temperature (IAT) or Vane Air Temperature (VAT) signal high
55 No or low (under 7.5 V) Key Power to PCM pin 5
56 Vane Air Flow (VAF) or Mass Air Flow (MAF) sensor high
(Running) Transmission Oil Temperature sensor too high
57 Intermittent in Park/Neutral/ Switch or Neutral Pressure switch circuit
58 Idle Tracking Switch (ITS) signal problem
Vane Air Temperature (VAT) sensor out of range or open
59 AXOD 4/3 circuit fault
3.0L SHO - Low speed fuel pump circuit problem
Transmission 2/3 shift problem
61 Engine Coolant Temperature (ECT) sensor is or was too low
62 AXOD (off)3/2 circuit short to ground
AXOD (Running) 4/3 circuit failure
63 Throttle Position Sensor (TPS) signal too low
64 Intake Air Temperature (IAT) or Vane Air Temperature (VAT) signal low or grounded
65 Check intermittent HO2S (signal or ground)
66 Vane Air Flow (VAF) or Mass Air Flow (MAF) signal low
Transmission Oil Temperature (TOT) signal low (possibly grounded)
67 Park/Neutral circuit fault
Transmission Manual Lever Position (MLP) sensor circuit
(M) Intermittent Park Neutral Position (PNP) sensor fault
68 Idle Tracking Switch (ITS) circuit (possibly grounded)
Vane Air Temperature (VAT) sensor out of range or grounded
3.8L AXOD -Transmission Temperature Switch (TTS) open
Electronic Transmission - Transmission Oil Temperature (TOT) sensor was overheated
69 AXOD transmission 3/2 switch closed (possible short circuit)
AXOD 3/2 switch open (poss short to power)
E4OD 3/4 shift problem
70 3.8L AXOD - Data link to instrument cluster fault. Service any other EEC codes, erase memory and retest.
If code is still present refer to instrument cluster diagnosis manual.
71 1.9L TBI, 2.3L TBI, 2.5L TBI - ITS signal was grounded when throttle should have been opening ITS
ISC motor problem or Idle Tracking Switch (ITS) signal wire shorted to ground
1.9L MFI - PCM re-initialized. Possible electrical noise, case ground or intermittent VPWR problem Diagnosis
3.8L AXOD - Data link to instrument cluster fault - See code 70
72 No MAP or MAF change in "goose" test - retest, check for frequency or voltage change
(M) 1.9L MFI - VPWR circuit to PCM was intermittent
2.3L T/C - PCM re-initialized. Possible electrical noise, case ground or intermittent VPWR problem
3.8L AXOD - Message center data link circuit fault - See code 70
73 Rerun test, if 73 is still output replace TPS
No Throttle Position Sensor (TPS) change in "goose" test. Must get at least 25% throttle rotation
74 Was brake depressed after engine ID was received ?
Brake On Off (BOO) signal open or short to ground
75 Brake On Off (BOO) signal shorted to power
76 Vane Air Flow (VAF) did not respond to "goose" test
77 System did not receive "goose" test
78 VPWR circuit to PCM was intermittent or the PCM is bad
79 A/C is on or pin 10 is shorted to power
81 Boost control solenoid
AIRD solenoid
3.0L SHO - Inlet Air Solenoid
82 2.3L TC - Fan Control wire shorted to ground
AIRB solenoid
3.8L SC - Super Charger Bypass Solenoid
83 High Electro Drive Fan circuit fault
EGR Control solenoid
3.0L SHO - Low Speed Fuel Pump Relay circuit
84 EGR Vacuum Regulator
EGR cutoff solenoid
EGR Vent solenoid
85 2.3L T/C Automatic - 3/4-4/3 Shift solenoid
CANP solenoid (ALL 1989)
1.9L MFI - System has corrected rich condition
86 2.3L or 2.9L Truck - A4LD 3/4 shift solenoid
1.9L MFI - System has corrected lean condition
87 Fuel pump circuit fault (check inertia switch)
intermittent in fuel pump primary circuit
88 Throttle Kicker Solenoid
Variable Voltage Choke relay circuit fault
Fan Control circuit fault
A4LD - Converter Clutch Override solenoid
Electronic Ignition - IDM, DPI or spout circuit fault
89 A4LD - Converter Clutch Override solenoid
AXOD Torque Converter Control solenoid circuit
Exhaust Heat Control (heat riser) solenoid circuit
91 System running lean
Transmission SS 1 circuit/solenoid problem
92 System running rich
Transmission SS 2 circuit/solenoid problem
93 Throttle linkage binding or bad ISC motor ISC HO2S not reading
Transmission TCC circuit/solenoid problem
94 AIR system inoperative
Transmission TCC circuit/solenoid problem
95 Fuel pump: open, bad ground or always on
AIR not Diverting (AIRD)
(M) Possible bad fuel pump ground or open between fuel pump and pin 8 at PCM (Fuel Pump Monitor signal)
96 Fuel pump monitor circuit shows no power
AIR Bypass (AIRB) not working
(Service 87 code first if present) Fuel pump relay or battery power feed was open
97 E4OD OD cancel light circuit failure
98 Did not pass KOEO yet (Get 11 in KOEO first)
Transmission EPC circuit/solenoid failure
99 ISC needs to learn (Let idle for 2 minutes; Erase memory and retest)
Transmission EPC circuit/solenoid failure