1994 PCED OBDI-A | SECTION 18A: Diesel Diagnosis — 7.3L DI Engine |
Z1 DTC 153: ICP CIRCUIT LOW INPUT
DTC 153 indicates injector control signal out of range low was detected during KOEO Self-Test or during continuous diagnostic monitoring.
Possible causes:
- Biased sensor/PCM.
- Open ICP sensor circuit.
- Short to SIG RTN or PWR GND on ICP sensor circuit.
- Key off.
- Disconnect ICP sensor.
- Disconnect PCM, check for damaged pins, etc.
- Connect breakout box. Leave PCM disconnected.
- Measure resistance between ICP terminal C on sensor harness connector and Pin 87 on breakout box.
Is resistance less than 5.0 ohms?
| Yes | No |
|---|
| GO to Z2. | SERVICE open circuit. RERUN Scan Tool Diagnostic Test. |
Z2 CHECK CIRCUIT 812 (DB/LG) FOR SHORT
- Disconnect ICP sensor.
- Disconnect PCM. Check for damaged pins, etc.
- Connect breakout box. Leave PCM disconnected.
- Measure resistance between Pin 87 and Pins 91/51/76/77 and 103 on breakout box.
Is resistance greater than 10,000 ohms?
| Yes | No |
|---|
| GO to Z3. | SERVICE short in Circuit 812 (DB/LG). RERUN Scan Tool Diagnostic Test. |
Z3 CHECK FOR SHORT ON PIN 87
- Disconnect ICP sensor.
- Connect breakout box and PCM.
- Measure resistance between Pins 87 and Pins 91/51/76/77 and 103.
Is resistance greater than 10,000 ohms?
| Yes | No |
|---|
| REPLACE ICP sensor. RERUN Scan Tool Diagnostic Test. | REPLACE PCM. REMOVE breakout box. RECONNECT ICP sensor. RERUN Scan Tool Diagnostic Test. |
Z4 DTC 154: ICP CIRCUIT HIGH INPUT
DTC 154 indicates injector control pressure out of range high during KOEO Self-Test or during continuous diagnostic monitoring.
Possible causes:
- Biased sensor/PCM.
- ICP circuit shorted to VREF.
- Key off.
- Disconnect ICP sensor.
- Disconnect PCM. Check for damaged pins, etc.
- Connect breakout box. Leave PCM disconnected.
- Measure resistance between Pin 87 and Pin 90.
Is resistance greater than 10,000 ohms?
| Yes | No |
|---|
| GO to Z5. | SERVICE short circuit. RERUN Scan Tool Diagnostic Test. |
Z5 CHECK FOR SHORT ON PIN 87
- Disconnect ICP sensor.
- Connect breakout box and PCM.
- Measure resistance between Pin 87 and Pin 90.
Is resistance greater than 10,000 ohms?
| Yes | No |
|---|
| REPLACE ICP sensor. RERUN Scan Tool Diagnostic Test. | REPLACE PCM. REMOVE breakout box. RECONNECT ICP sensor. RERUN Scan Tool Diagnostic Test. |
Z6 DTC 819: ICP HIGHER THAN EXPECTED
- DTC 819 indicates signal voltage greater than 1.625 volts with the engine off.
- Possible causes:
- Biased sensor.
- Biased circuit.
- Key off.
- Disconnect ICP sensor.
- Disconnect PCM, check for damaged pins, etc.
- Connect breakout box. Leave PCM disconnected.
- Key on.
- Measure voltage between Pin 87 and ground.
Is voltage greater than 1.625 volts?
| Yes | No |
|---|
| SERVICE Circuit 812 (DB/LG) as required. RERUN Scan Tool Diagnostic Test. | Biased ICP sensor. REPLACE sensor. RERUN Scan Tool Diagnostic Test. |
Z: Introduction