yo, Some info for now;
DTC 54; the Intake Air Temp (IAT), (Air Charge Temperature [ACT] prior to 1992)
Source: by miesk5 at Ford Bronco Zone ForumsOverview & Testing; "...
The ambient temperature should be above 50�F (10�C) to receive acceptable input from the Air Charge Temperature (ACT) sensor during the KOEO and KOER Self-Test. To accomplish this, the engine should be at normal operating temperature.
This measures the temperature of the air entering the engine. Which impacts the fuel ratio; the cooler the incoming air is the denser it is. Denser air can utilize more fuel, giving us even greater accuracy in obtaining our desired air to fuel ratio. Before you start blaming the air charge temperature sensor and replacing it make sure the rest of the coolant system is in good condition. All of the following items will affect the ACT; Coolant level, Radiator Fan, Engine Temperature, and more; Values were calculated for VREF=5.0 volts.These values may vary 15 percent due to
sensor and VREF variations
..." READ MORE
Source: by Ryan M (Fireguy50) at
http://oldfuelinjection.com/?p=29
Symptoms; Check Engine light is on continuously, hesitation, poor mileage or rich exhaust odor, poor performance and economy. Inspect for damage or corrosion on terminals. Check sensor for carbon accumulation or contaminants which can cause false readings.
-----------
In following Pin-Point Testing, where Breakout Box is cited; go to the EEC IV Pin instead;
EEC
IV Connector Pin Depiction Pic by Ryan M (Fireguy50)
EEC IV Connector Pin Legend by Ryan M (Fireguy50) @
http://oldfuelinjection.com/truckpinouts.html
Wiring Diagram in an 89 (From TAD & TAD to EEC IV)
Source: by SeattleFSB (Seattle FSB) at SuperMotors.net
DTC 81/553 and
82/552 indicate voltage output for secondary air injection solenoid did not change when activated. Possible causes for this fault are:
• AIRB/AIRD circuit(s) shorted or open.
• Fault in solenoid or PCM.
Disconnect both solenoid connectors. Turn ignition on. Measure voltage between VPWR terminal of wiring harness connector and battery ground for both solenoids. If either voltage reading is less than 10.5 volts, repair wiring harness open circuit, and repeat QUICK TEST. If both readings are 10.5 volts or more, go to step 9).
9)Measure Solenoid Resistance :
Turn ignition off. Leave solenoid connectors disconnected. Measure resistance of both solenoids. If either reading is not 50-100 ohms, replace solenoid assembly and repeat QUICK TEST. If both readings are 50-100 ohms, go to step 10).
10) Check Circuit Continuity :
Leave ignition off. Disconnect PCM 60-pin connector. Inspect terminals, and repair if damaged. Install EEC-IV Breakout Box (T83L-50-EEC-IV), leaving PCM disconnected. Measure resistance between AIRB test pin and AIRB terminal at wiring harness connector. Measure resistance between AIRD test pin and AIRD terminal at wiring harness connector. If either reading is 5 ohms or more, repair open circuit and repeat QUICK TEST. If both readings are less than 5 ohms, go to step 11).
11) Check For Short To Ground :
Leave ignition off and solenoids disconnected. Measure resistance between test pin No. 51 and test pins No. 40, 46 and 60 at breakout box. Measure resistance between test pin No. 11 and test pins No. 40, 46 and 60. If any reading is less than 10,000 ohms, repair short to ground and repeat QUICK TEST. If all readings are 10,000 ohms or more, go to step 12).
12) Check For Short To Power Circuit :
Turn ignition off. Measure resistance between test pin No. 51 and test pins No. 37 and 57 at break-out box. Measure resistance between test pin No. 11 and test pins No. 37 and 57 at breakout box. If any resistance is less than 10,000 ohms, repair short to power and repeat QUICK TEST. If code is repeated, replace PCM. If all resistances are 10,000 ohms or more, replace PCM and repeat QUICK TEST.
I'll post up for now; expecting a replacement Comcast Modem now to alleviate pre 1996 download speeds