DR-1A CODE to DR TEST Chart (Checking for Fault Codes)

1. Connect diagnostic readout box to engine harness connector.
2. Within five seconds, cycle ignition on and off two times, then turn on and record all codes. If Codes 12, 22, 25, 26 or 28 are displayed, proceed to Test indication.
3. Turn ignition switch Off, then disconnect the computer 14-way connector for one minute and reconnect it.
4. Disconnect the diagnostic readout box.
5. Start engine and run for two minutes, then turn engine Off.
6. Reconnect the diagnostic readout box.
7. Within five seconds, cycle ignition on and off two times, then turn on and record all codes.
8. If codes displayed are the same as those in step 2, proceed to Test indications. If codes are not repeated, proceed to Step G.
9. Initiate the appropriate diagnosis for the following fault code displays:
a. Code sequence 88-14-55 indicates no fault codes are present. Proceed to Step B DR-1B Output Circuits of ECM Controlled Components
b. Code sequence 88-11-14-55 or 88-11-14-22-55 indicates a fault in the oxygen sensor circuit. Proceed to Test 22DR-2A Fault Code 11-Oxygen Solenoid Circuit
c. Code sequence 88-12-14-55 indicates a fault in the transmission unlock relay. Proceed to Test 3 DR-3A Fault Code 12-Transmission Unlock Relay
d. Code sequence 88-13-14-55 indicates a fault in the air switching solenoid circuit. Proceed to Test 4 DR-4A Fault Code 13-Air Switching Solenoid
e. Code sequence 88-14-17-55 indicates a fault in the throttle control solenoid. Proceed to Test 5 DR-5A Fault Code 17-Throttle Control Solenoid
f. Code sequence 88-14-18-55 indicates a fault in the EGR system or canister purge control solenoid. Proceed to Test 6 DR-6A Fault Code 18-EGR or Canister Purge Solenoid
g. Code sequence 88-14-22-55 indicates a fault in the oxygen feedback system circuit. Proceed to Test 7 DR-7A Fault Code 22-Oxygen Feedback System
h. Code sequence 88-14-24-55 indicates a fault in the vacuum sensor circuit. Replace computer.
i. Code sequence 88-14-25-55 indicates a fault in the charge temperature circuit. Proceed to Test 8 DR-8A Fault Code 25-Charge Temperature Switch
j. Code sequence 88-14-26-55 indicates a fault in the engine temperature circuit. Proceed to Test 9 DR-9A Fault Code 26-Engine Temperature Sensor
k. Code sequence 88-14-28-55 indicates a fault in the speed sensor circuit. Proceed to Test 10 DR-10A Fault Code 28-Speed Sensor Circuit
l. Code sequence 88-14-32-55, 88-14-33-55 or 88-11-13-14-16-17-18-55 indicates a fault in the computer. Replace computer.
m. Code sequence 88-13-14-18-55 indicates an open circuit in ignition feed wire. Repair open circuit in ignition feed wire to dual solenoids.
n. No code 88 after switch is moved to Hold position indicates a faulty computer. Proceed to Test 11 DR-11A Checking For No Code 88 Ensure diagnostic readout box is operational.

o. No code 00, check diagnostic readout connector ignition and ground wire for open circuits. If okay, repair readout box.