1994 PCED OBDI-A | SECTION 18A: Diesel Diagnosis — 7.3L DI Engine |
AA1 DIAGNOSTIC TROUBLE CODE (DTC) 124/125
- With engine running in idle mode.
- Slowly depress accelerator pedal.
Does engine remain at idle?
| Yes | No |
|---|
| GO to AA2. | PERFORM KOEO wiggle test. CHECK pedal and RERUN Scan Tool Diagnostic Test. |
AA2 CHECK CIRCUIT 16 FOR VOLTAGE
- Key on.
- Disconnect IVS connector at accelerator pedal.
- Check with DVOM for voltage at connector Circuit 16 (R/G).
Is B+ present?
| Yes | No |
|---|
| GO to AA3. | REPAIR open in Circuit 16. |
AA3 CHECK IVS SWITCH
- Measure continuity across IVS switch on pedal with pedal released.
Is there continuity?
| Yes | No |
|---|
| REPLACE pedal and switch assembly. | GO to AA4. |
AA4 CHECK IVS SWITCH
- Measure continuity across IVS switch on pedal with pedal depressed.
Is there continuity?
| Yes | No |
|---|
| GO to AA5. | REPLACE pedal and switch assembly. |
AA5 CHECK PINS FOR DAMAGE
- Disconnect PCM.
- Check for damaged or corroded pins.
Are the pins on the PCM OK?
| Yes | No |
|---|
| GO to AA6. | REPAIR or REPLACE damaged unit. |
AA6 CHECK CIRCUIT 308 (R/O) FOR OPEN
- Connect breakout box. Leave the PCM disconnected.
- Key off.
- With a volt ohmmeter check for continuity between IVS connector Pin A Circuit 308 (R/O) to Test Pin 5 at breakout box.
Is there continuity?
| Yes | No |
|---|
| GO to AA7. | REPAIR open in circuit. RERUN Scan Tool Diagnostic Test. |
AA7 CHECK CIRCUIT 308 (R/O) FOR SHORT
- Key off.
- Disconnect IVS switch.
- Measure continuity between Test Pin 5 and battery ground.
Is there continuity?
| Yes | No |
|---|
| REPLACE PCM. RERUN Scan Tool Diagnostic Test. If DTC 125 is present with 122 or 123. GO to AA8. | REPAIR open in circuit. RERUN Scan Tool Diagnostic Test. If DTC 125 is present with DTCs 122 or 123. GO to AA8. |
AA8 CHECK FOR DISAGREEMENT BETWEEN IVS AND AP
- Run Diagnostic Scan Tool Test.
Is DTC 125 present with DTC 122 or 123?
| Yes | No |
|---|
| GO to E1. | GO to AA9. |
AA9 CHECK IVS AND AP VOLTAGES
- Install breakout box.
- Using two Digital Volt Ohmmeters check Pin 89, 0 to 5 volts and Pin 5, 0 to 12 volts.
- Slowly depress the accelerator pedal holding it in position when the voltage reading on Pin 5 goes to 12 volts.
Is the voltage reading on Pin 89 less than 1.55 volts?
| Yes | No |
|---|
| Pedal and sensor assembly OK. CHECK harness for intermittent faults. | REPLACE pedal and sensor assembly. CHECK for proper operation. |
AA: Introduction